2020-09-01_Astronomy.pdf

A shadow crosses

With a bit of planning,
you can witness this year’s
total solar eclipse.

BY MICHAEL E. BAKICH

ON DECEMBER 14, the total On December 14, the
solar eclipse on Moon’s umbra (dark inner
celestial drama once again December 14, 2020, will race shadow) first touches Earth in the
unfolds as the Sun and Moon across the same two countries — Chile central Pacific Ocean. It vanishes at sunset in
line up with Earth to produce and Argentina — as it did during the the Atlantic Ocean near the African coast. This map
the greatest of nature’s spec- eclipse of July 2, 2019. This year, the only shows the center line in yellow and the progression
tacles: a total solar eclipse. other land off of the main mass of South of the umbra in 10-minute increments. MICHAEL ZEILER
America to experience totality will be
Although total solar eclipses Isla Mocha, a Chilean island. All told, after sunrise, which occurs at 14h32m
occur more often than total lunar only about 5 percent of this eclipse’s UT, 466 miles (750 kilometers) east of
ones, more people have seen the totality path falls on land. Nuku Hiva, the largest of the Marquesas
latter. The reason is simple: During Islands, at longitude 132°49'39" west
a lunar eclipse, anyone on the night- The finer details and latitude 7°46'22" south. The umbra
side of our planet under a clear sky remains in contact with Earth’s sur-
can see the Moon passing through The Moon’s penumbra first touches face for 3 hours 21 minutes 45 seconds,
Earth’s shadow. Earth at 13h33m48s UT and last con- until 17h54m13s UT, when it vanishes
tacts it at 18h53m00s UT. The total 217 miles (350 km) off the Namibian
Even at the Moon’s distance, Earth’s phase of the eclipse begins 28 seconds coast at longitude 11°01'22" east and
shadow is much larger than the lunar
disk. If the Moon passes through the
center of Earth’s shadow, totality can last
as long as 106 minutes. It’s usually less,
because the Moon often passes either
above or below the shadow’s center.

On the other hand, the Moon’s
shadow barely reaches Earth’s surface
during solar eclipses. If you’re beneath
the lighter outer region of the shadow,
called the penumbra, you’ll see a partial
eclipse. The lucky individuals under the
dark inner shadow, or umbra, will expe-
rience a total solar eclipse.

But, although dramatic, the event is
brief. Solar totality lasts a maximum of
7 minutes 29 seconds. Unfortunately, the
next eclipse sporting that duration won’t
occur until July 16, 2186.

The Moon’s umbral shadow during

50 ASTRONOMY • SEPTEMBER 2020

latitude 23°37'28" south. The total path
length is 9,239 miles (14,869 km).

This eclipse is total because at the
time of the event, the Sun’s apparent
diameter is 32'30", while the Moon’s
apparent span is slightly larger at 32'48".
Greatest eclipse occurs at 16h13m23s UT
at longitude 67°56' west and latitude
40°21' south. The maximum duration
of totality is 2 minutes 10 seconds.

The sky during the eclipse

In December, the Sun and Moon lie

in Ophiuchus the Serpent-bearer, one

of the southernmost constellations the

Sun passes through during the year. At

the moment of greatest eclipse, the Sun’s

right ascension will be 17h30m06s and

its declination will be –23°15'32". As

a result, the Sun’s altitude from any

land location will be at least 71.4° at This 2-hour 23-minute sequence shows the March 9, 2016, eclipse at Palu, Central Sulawesi, Indonesia. From
mid-totality. beginning to end, it spans some 36º. At this location, totality lasted 2 minutes 31 seconds. MUHAMMAD RAYHAN

Observers who enjoy favorable con-

ditions will be in for a nice planetary

show. During totality, the planet nearest earlier. Be extremely careful not to point It glows at magnitude 1.1, which means

the Sun will be Mercury. The innermost any unfiltered optical device near the Sun. it’s only 60 percent as bright as Saturn.

world will lie a bit more than 3° west- With our star obscured by the Moon, Still, if you’d like to try to snag it, aim

southwest of our daytime star. Sharp- it also should be possible to spot two your binoculars 14° west of the Sun.

eyed observers using binoculars will giant outer planets, which lie within 1° of

certainly spot Mercury, glowing at mag- each other. Jupiter will shine at magni- The eclipse in Chile

nitude –1.0 during totality. Depending tude –2.0, and Saturn will glow at magni- Because the umbra initially contacts

on the sky’s transparency at your observ- tude 0.6. Both will lie 36° east of the Sun. Earth in the center of the Pacific

ing site, it might even become visible to Jupiter, three and a half times brighter Ocean, it travels more than 3,000 miles

the naked eye. than Saturn, shouldn’t pose a problem (4,830 km) before it touches land. That

The visibility of Mercury might be for naked-eye observers. Once you find first territory, Isla Mocha, belongs to

in question, but there’s no doubt about it, use binoculars to locate nearby Saturn. the Republic of Chile. The Moon’s inner

Venus, which will lie nearly 25° west of One thing to remember if you’re going to shadow reaches the southwestern tip

the Sun. Shining at magnitude –4.0, this search for these planets is that the real of this island at 15h58m55s UT. There,

planet may be visible to even casual spectacle is the Sun’s corona, so don’t totality will last 1 minute 19 seconds,

observers up to 15 minutes before total- devote many seconds to the endeavor. with the Sun 71° high.

ity. Knowing where to look should let As far as stars go, the only bright one The island’s northern edge lies at the

you pinpoint it through binoculars even in the area is Antares (Alpha [α] Scorpii). northern limit of totality. Here, and for

16 miles (25 km) south along the coast,

is where climate statistics say observers

will likely find the best weather in Chile.

Conveniently, it’s neither difficult nor

expensive to travel to the island.

The umbra first encounters the

Chilean mainland at Champulli, which

lies 50 miles (80 km) west of Temuco. As

a city with some 300,000 residents and

corresponding amenities, Temuco will

undoubtedly be the destination of choice

for many eclipse chasers. From Temuco,

it’s a quick 30-mile (50 km) drive down

Highway 5 to either Gorbea or El Liuco,

The diamond rings before and after totality were spectacular from Australia during the November 14, 2012, both of which will enjoy nearly 2 minutes
eclipse. The small reddish arcs above the Moon’s black disk are solar prominences. BEN COOPER 9 seconds of totality.

WWW.ASTRONOMY.COM 51

LEFT: No one who experienced the July 11, 2010,
eclipse from Rapa Nui (Easter Island) will ever
forget it. The sight of the eclipsed Sun 40º above
the famous moai statues was the highlight of the
trip. GIORGIO MASSIGNANI

RIGHT: A close-up of the December 2020 eclipse’s
umbral path through South America is seen in this
map. Eclipse chasers take note: The closer you are to
the center line, the longer totality will last. MICHAEL ZEILER

On December 14, One spot that might offer an intrigu- watchers is Los Menucos, a town of some
celestial drama ing photographic opportunity is the 3,000 residents, which lies just outside
once again unfolds southern side of Villarrica, one of Chile’s the southern limit of totality. The mid-
as the Sun and most active volcanoes. There, the eclipse point of the eclipse lies 37 miles (60 km)
Moon line up with will last 2 minutes 6 seconds, with the north of Los Menucos and experiences
Earth to produce Sun 72° high in the north-northeast. 2 minutes 10 seconds of totality, but
the greatest of no roads go to it. Travelers who drive
nature’s spectacles: Before leaving Chile, the Moon’s 53 miles (85 km) to the northeast along
umbra quickly encounters two other vol- Highway 23 to the small village of
A TOTAL SOLAR canoes within Villarrica National Park: Ministro Ramos Mexia can get the
ECLIPSE. Quetrupillan and Lanin, which sit on the equivalent length of totality.
country’s border with Argentina.
TRAVEL TO TOTALITY
Chile is a long country, but it’s not
wide. The total length of the umbra’s Astronomy magazine and TravelQuest
path through it, therefore, is only about International offer three opportunities to
100 miles (160 km). witness this December’s total eclipse. Go
to www.travelquesttours.com for details.
According to Canadian meteorologist
Jay Anderson, the acknowledged expert
when it comes to predicting weather
for eclipses, the coastal region west of
Teodoro Schmidt offers the most promis-
ing weather prospects in mainland Chile.
The lower cloudiness (an average of
45 percent) occurs because cool air from
the Pacific suppresses the formation of
convective clouds. He writes on his web-
site, eclipsophile.com, “The best cloud
prospects on the coast are even better
on the south side of the track where the
terrain is roughest, but the benefit is only
about 5 percent.”

After Teodoro Schmidt, average cloud
cover goes up a bit, peaking at 52 percent
east of Gorbea before declining to 45 per-
cent at Villarrica. This decrease is due
partly to the distance from the ocean and
partly to the cooling effects of Lake
Villarrica, which suppresses convection.

The eclipse in Argentina Argentina and Brazil Total Solar Eclipse
Spend three nights each in Rio de Janeiro,
The second country the umbra touches Iguazu Falls, Bariloche, and Buenos Aires.
offers better weather and the longest
totality. In fact, every point along the Wonders of Chile Total Solar Eclipse
center line in Argentina offers a dura- Spend two nights in Santiago and three
tion of totality within one second of the nights in the Atacama Desert with prime
maximum. dark-sky observing, and much more.

As the Moon’s shadow crosses from South Pacific Cruise to Totality
Chile into Argentina, it encounters a vast Enjoy 15 days aboard the privately
stretch of small villages and rough roads. chartered M/S Paul Gaugin.
One possible destination for eclipse

Another destination to consider is This wide-angle shot of the March 20, 2015, eclipse highlights the landscape near the Svalbard archipelago
Valcheta, a town of nearly 4,000, which in Norway. Venus is visible to the upper left of the solar corona. TUNÇ TEZEL
lies just north of the center line (and also
on Highway 23). From there, totality will East of Junín de los Andes, where Unfortunately, as I write this story
last 2 minutes 9 seconds, with the Sun totality will last 1 minute 1 second, the (at the beginning of June), restrictions
73° high in the north at mideclipse. mean cloud cover drops below 40 percent on international travel are high due
until the track reaches the Atlantic coast to the COVID-19 threat, so it’s unclear
Better accommodations, but less at San Antonio Oeste. Afternoon clouds whether amateur astronomers outside
favorable weather prospects, will be are less frequent in Argentina than in of Chile or Argentina will be able to
found at the coastal towns of San Chile, but the savvy eclipse chaser will view totality. Hopefully, a vaccine or
Antonio Oeste, San Antonio Este, and stay mobile enough to make a last-minute treatment will soon open up our world
Las Grutas. And although Las Grutas’ change of location if necessary. and we’ll once again be able to experi-
population is just 8,000, some 400,000 ence the spectacle of darkness at
tourists visit it during the summer, More water midday.
which, in Argentina, begins a week after
the eclipse. The center line, with its After leaving Argentina, the umbra Michael E. Bakich is a contributing editor
2 minutes 9 seconds of totality, lies only travels another 3,000 miles (4,830 km), of Astronomy and is co-author of Atlas of
6 miles (10 km) south of this town. nearly the width of the Atlantic Ocean, Solar Eclipses 2020 to 2045 with eclipse
Observers in the northern sections before the eclipse ends a scant 155 miles mapmaker Michael Zeiler.
of San Antonio Oeste will lose nearly (250 km) short of the Namibian coast.
20 seconds from that duration.

According to Anderson, weather pros-
pects throughout Argentina are best on
the western side of the country, where
the sunniest and driest areas lie along the
eastern edge of the Andes Mountains.
Eclipse chasers may want to head for the
village of Piedra del Aguila, which offers
the best weather prospects. Don’t go too
far west, though, because cloudiness is
highest near the Chilean border.

WWW.ASTRONOMY.COM 53

Some of the greatest splendors of the
cosmos lie in the Southern Hemisphere.

BY DAVID J. EICHER

Deep-sky observing from

COSTA RICA

Howler monkeys are among IF YOU’RE AN OBSERVER OF THE SKIES,
the numerous creatures in and
around our Costa Rica base you undoubtedly have fond memories of gazing up at
camp. TRAVELQUEST INTERNATIONAL Orion and taking in that misty “star” in the middle of the
Hunter’s sword. Viewed in a telescope, the Orion Nebula
54 ASTRONOMY • SEPTEMBER 2020 (M42) is a gray-green wonderland of gauzy glow, a nebu-

lous smear of gas that is collapsing down into newborn
stars. The brilliant Trapezium, a dazzling gem of four
bright stars, acts as the nebula’s centerpiece.

But if you’ve never seen a Southern Hemisphere sky,
you’ve never had the “Orion Nebula shock,” as I call it.
That’s when you gaze up at M42 and then look over to
the east and see the Carina Nebula rising. Much as we

may love Orion, the Carina Nebula is factors larger
and brighter, in a class by itself.

This past February, I had the great pleasure to
accompany a group of Astronomy readers down to
Costa Rica for our annual star party, which lets us
see the wonders we can never glimpse from the

North. We had a small but dedicated group of
about 20 this year, all primed to observe the
southern skies from a Star Lodge plantation
camp north of Puntarenas, on the Gulf of
Nicoya, near the country’s western edge. Costa Rica is a
splendid place and our site offered an incredible natural adventure
in addition to the sky, with daily walks to spy dozens of bird species,
howler monkeys, crocodiles, and other critters. We swam, rode
horses, and enjoyed the beauty of the locale, which is easy to get
to — a mere three-hour flight from Miami.
Our 2020 trip was a joint venture with Astronomy’s travel partner,
TravelQuest International. The endeavor was ably led by our maestro
of logistics and organization, TravelQuest’s Cody Carter.

A new view

This year, we had the great fortune to raise the bar for our astronomi-
cal observing. I transported an Explore Scientific 16-inch Truss Tube
Dobsonian telescope down to the site, outfitted with three of Scott
Roberts’ gorgeous eyepieces. The 2" 82° apparent field of view 30mm
eyepiece, which we used the most for deep-sky objects, is a perfect
eyepiece for the 16-inch, yielding views that were akin to peering into
a huge porthole. If you’re looking for a transportable, large-aperture
deep-sky scope, I highly recommend this instrument. It was a joy to

ABOVE: The southern sky holds numerous
treasures, starting with the Southern Cross,
Crux (center). The uppermost star in the cross,
Gacrux, is the closest red giant star to our Sun
at 89 light-years. The great dark Coalsack
Nebula lies to the lower left of the cross. Near
the right edge of the shot is the Carina Nebula
and near the left edge are the bright stars
Alpha and Beta Centauri. Yellow-hued Alpha,
farthest left, is the closest star system to the
Sun, just 4.3 light-years away. YURI BELETSKY

LEFT: Astronomy magazine’s group of travelers
enjoyed a splendid week under dark Costa
Rican skies. Here, they pose with the new
16-inch Explore Scientific Dobsonian, which
provided spectacular views of deep-sky
objects, including the Orion and Carina
nebulae, and Omega Centauri. DAVID J. EICHER

WWW.ASTRONOMY.COM 55

apparent at low power, even without proper dark adap-

tion. Our 16-inch Dobsonian showed bright deep-sky

objects like M42 as almost photographic in their detail,

simply lacking the faint portions visible in long-exposure

images and the myriad colors human eye receptors are

not structured to detect.

We also explored some other goodies in Orion, such

as M78, one of the sky’s best reflection nebulae, which

appears as a more-or-less circular haze surrounding

bright stars. We next turned to the small, bright plan-

etary nebula NGC 2022, a view of what our solar system

may be like in 6 billion to 7 billion years. Near Orion, we

wandered over to see two of the gems of Monoceros: the

Rosette Nebula and the Cone Nebula.

The Rosette Nebula, a showpiece in astrophotos, is a

wreath-shaped emission nebula with a pronounced cen-

tral hole that contains a bright star cluster, NGC 2244.

The nebula’s surface brightness is rather low; that is, indi-

vidual parts of it appear rather dim, so it glows faintly as

a circular, mottled haze. The bright star cluster stands out

strongly, however, and the 16-inch scope revealed traces

of the dark knots and nebulae intertwined with

the bright gas — globules that are

condensing down into stars. The

Cone Nebula is a relatively easily

visible prominent dark nebula,

which lies near an associated star

use and gave me the best views of cluster, NGC 2264 — sometimes
Southern Hemisphere treasures
I’ve ever had. called the Christmas Tree Cluster

The scope was remarkably easy because of its distinctive shape.
to set up, and collimation, assisted
by our HOTECH laser collimator, Also nearby in Puppis, we
was similarly simple. Once we
had the telescope assembled, viewed two beautiful star clusters
I found that I could get it
ready for the evening in that shouldn’t be missed. Located
about 20 minutes. And the
views of myriad deep-space near each other, M46 and M47 offer
objects were mind-blowing.
a marked contrast. M46 is composed
Familiar favorites
of numerous faint stars, making the
In late February in Costa Rica,
the darkening evening twilight cluster appear as a richly appointed
brings on a sky shimmering
with the bright stars of the win- cloud of tiny bees. And there’s a
ter Milky Way. The first thing we
typically turned to was the Orion bonus: The planetary nebula NGC 2438,
Nebula — always a show-stopper
not only for our own guests, but a perfect ring shape, appears encased
for the local families and kids who
came in one night to have what was, within the cluster. It’s actually a fore-
for many, their first view of the distant
cosmos. The dark “fish’s mouth” near ground object, but the two make a
the nebula’s center, the bright stars of
the Trapezium, and the winged shape beautiful eyepiece field. By contrast,
of the glowing gas extending upward
away from the nebula’s base were all M47 is a looser cluster made up of

56 ASTRONOMY • SEPTEMBER 2020 much brighter stars.

Next, we explored the vistas of

Taurus. The central portion of this

constellation, making up the Bull’s

TOP LEFT: A favorite object of head, is the Hyades star cluster. At
many stargazers, the Orion Nebula 151 light-years, it is one of the closest
can be seen as the misty “star” in physically associated groups of stars
the center of Orion’s sword. It is a to us. Aldebaran, the brightest star in
vast star-forming region in which the V-shaped group, is a red giant that
hydrogen gas is gravitationally lies in front of the cluster, 65 light-
collapsing, creating newborn stars. years away.

TONY HALLAS

ABOVE: Costa Rica’s western coast Not far from the Hyades is the
is a birdwatcher’s paradise, and is other great cluster in Taurus, the
also home to curious creatures Pleiades, famous to naked-eye viewers
such as tapirs. TRAVELQUEST INTERNATIONAL

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CLOCKWISE FROM TOP: Draped in gauzy Telescopes line up awaiting Our southern sky Star Lodge lies A wide-field image of the Orion area
reflection nebulosity, the Pleiades star another clear night at our base on the Gulf of Nicoya, northwest of shows the magnificent Hunter; within
cluster in Taurus is one of the closest camp. TRAVELQUEST INTERNATIONAL Puntarenas, and offers dark skies. his outline are the Orion Nebula and
such star groups to us at 445 light-years. the faint arc of Barnard’s Loop. The
Visible to the naked eye as the Seven ASTRONOMY: ROEN KELLY bright red Rosette Nebula is to his
Sisters, it is a magnificent binocular target left and Canis Major with Sirius, the
and so large that only low-power scopes brightest star in the sky, below him.
show most of its stars. TERRY HANCOCK
LUKE DODD

WWW.ASTRONOMY.COM 57

NEXT YEAR’S as the Seven Sisters and Many other bright star clusters and some intriguing
PLANNED TRIP so large it is best suited nebulae also live in the area. One of the greatest is the
for binocular viewing. cluster IC 2602, sometimes called the Southern Pleiades,
which is so bright and scattered, it’s astonishing that
Join us on the 2021 Jewels of Costa Rica Lying 445 light-years off, more people don’t know about it. If it were in the north-
and the Southern Milky Way excursion. the Pleiades is another ern sky, it would be one of the most celebrated deep-sky
objects of all.
You can accompany Astronomy Editor close open cluster, and
Dave Eicher to view spectacular treasures with the 16-inch scope As each night progressed, Alpha and Beta Centauri
of the southern sky February 6–14, 2021. In we glimpsed some of the rose, trailing the Cross. It’s a thrill to see these stars for
association with TravelQuest International, nebulosity around one the first time — especially Alpha — even as a bright star
of its stars, Merope. This in a telescopic field. Alpha Centauri is the closest star
Astronomy readers will embark on an system to our Sun and consists of a bright double star
that is encircled by a distant third star, Proxima Centauri.
adventure to see Arenal Volcano National faint reflection nebulosity At 4.2 light-years, Proxima is a red dwarf and the closest
Park, Tabacón Hot Springs, and Monteverde is dust left over from the star to the Sun, a shade closer than the double.
cluster’s formation. And
Cloud Forest, with three nights of we had a terrific view of And that’s not all. There’s a huge panoply of great
unforgettable stargazing at our private the Crab Nebula, a super- stuff that rises after midnight and into the early morn-
ing February skies. How about Omega Centauri, the
plantation, Star Lodge. largest and brightest globular cluster in the Milky Way?
The view of this mighty sphere of stars in the 16-inch
You will take a joyride through the Carina nova remnant left from scope was truly jaw-dropping, as if we were viewing it
Nebula, Omega Centauri, the Southern the A.D. 1054 explosion. from orbit around the cluster. A short distance north of
It looked remarkably like Omega is the peculiar galaxy Centaurus A, a spectacular
Cross, and countless other southern sky a photograph in the showpiece that perhaps foreshadows our own galaxy’s
splendors with Dave and our 16-inch 16-inch scope, with wiry future. The result of a massive collision — two normal
galaxies creating a huge, actively star-forming ball with a
Explore Scientific Truss Tube Dobsonian broad dark band — Centaurus A is astonishing,
telescope, showing portholelike although somewhat shy with a low surface brightness.
The same chaotic future lies ahead with the Milky Way
views that will blow your mind. tendrils of gas branching and the Andromeda Galaxy when they merge.

For complete trip information, see out from the core. Then, in the early morning hours, came another
amazing treat. Most of us northerners are used to seeing
https://travelquesttours.com/eclipse-tours/ Seeking the center of the galaxy, Sagittarius and Scorpius, rela-
2021-jewels-of-costa-rica-and-the- southern gems tively low on the horizon. But stay up long enough on
southern-milky-way our Costa Rica jaunt and you could see them high in the
sky, their dozens of deep-sky treasures perched against
All the other treats of the inky blackness. The resulting telescopic views, especially
in a big scope, were amazing. The Lagoon and Trifid
winter Milky Way were nebulae, the Eagle and Omega nebulae, the Table of
Scorpius with brilliant cluster NGC 6231, Scutum and its
up there too, and high Wild Duck Cluster, the Bug Nebula, the Rho Ophiuchi
region ... the list goes on and on and on.
up, in a nicely dark sky. We waited until late evening,
I can tell you that an expedition south to see the skies
though, for the secret treats to rise — the far-southern is one of the most memorable an amateur astronomer
can take. We plan to journey once more to Costa Rica for
gems we cannot see at all back at home. As wonderful deep-sky observing in February 2021, and again will use
the 16-inch Explore Scientific Dobsonian we are so for-
as the Orion Nebula is, the Carina Nebula is far larger tunate to now have. See the sidebar for complete details
on how you can sign up for the adventure of a lifetime.
and brighter. Its three-pronged shape, separated into Not only will the Carina Nebula, the Southern Cross,
and Omega Centauri be waiting, but also howler mon-
wedges by a broad dust band, gives it a glowing, spidery keys, dozens of bird species, incredible forests, and many
other natural wonders that will make the trip unforget-
appearance in the big scope at low power, the field pep- table. I look forward to traveling with you next year.

pered with both bright and faint stars that show a range David J. Eicher is the editor of Astronomy and enjoys
Southern Hemisphere observing of some of his favorite
of color. The brightest star embedded within one of the deep-sky objects.

wedges of nebulosity is Eta Carinae, one of the most

massive stars known, and which has an enigmatic his-

tory. During much of the 19th century, it flared up to

dazzling naked-eye brightness before fading to near its

current magnitude.

Following the Carina Nebula as Earth turns is the

Southern Cross, not to be missed on any trip south. Its

topmost star is Gacrux, the closest M-class red giant to

the Sun at 89 light-years. The huge, dark Coalsack

Nebula covers the lower left quadrant of the Cross. Near

the scene’s left edge is one of the area’s most dazzling

open clusters, the Jewel Box (NGC 4755). This spectacu-

lar star group shone in the 16-inch scope

as a tight, colorful bead of

bright stars in a rich field.

The Star Lodge contains wide-
open fields with a great horizon all
around, ideal for telescope setups.

TRAVELQUEST INTERNATIONAL

LEFT COLUMN FROM TOP: RIGHT COLUMN FROM TOP:
Just north of Omega Centauri lies the The hook-shaped constellation
peculiar galaxy Centaurus A, the result Scorpius rises early in the morning in
of a merger between two ordinary late winter and offers a treasure trove
galaxies that has sparked a new round of dozens of bright deep-sky objects.
of star formation. The prominent dust Star clusters, bright and dark nebulae,
band in this galaxy is visible in small and planetary nebulae abound, making
telescopes. ESO this a gem for observers. LUKE DODD

The Star Lodge cabins comfortably The largest globular cluster in the
offer a base camp for deep-space Milky Way, Omega Centauri, is so
viewing. TRAVELQUEST INTERNATIONAL bright that it was mistaken for a naked-
eye star. A sphere of 1 million ancient
The Star Lodge pier extends into the stars, the cluster might have been a
Gulf of Nicoya, and boat trips take dwarf galaxy if not for a lack of mass.
visitors to see amazing animal life. It makes a splendid view in backyard
telescopes. LUKE DODD
TRAVELQUEST INTERNATIONAL

The centerpiece of Sagittarius is the
mighty star-forming region, the Lagoon
Nebula. This immense cloud of gas is
condensing down into a central star
cluster of blue-white, dazzling stars
that shine like diamonds in a
telescope’s eyepiece. ADAM BLOCK/MOUNT

LEMMON SKYCENTER/UNIVERSITY OF ARIZONA

WWW.ASTRONOMY.COM 59

TWESET Chroma filters

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Nearly three decades ago, a An exceptional The Unlike the filters from
handful of employees left coating reflection nebula many other companies,
their jobs at Omega Optical NGC 2170 sits in the
and founded Chroma constellation Monoceros. The
Technology in Vermont. author captured this image with
Since then, the company, which is entirely an SBIG STX-16803 CCD camera,
owned by its roughly 150 employees, has PlaneWave CDK17 telescope, and
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the biological life sciences, agriculture, energized matter.
security, and aerospace industries. But of
particular interest to Astronomy readers TONY HALLAS
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well as an anti-reflection coating on the the coating is as even as possible, right

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60 ASTRONOMY • SEPTEMBER 2020

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SECRET SKY

The 2020 Ghost Hunts.” Lashbrook said the evening, which
Ghost Hunt included a fall picnic, was a great success. The competi-
tion was four categories: manual telescope, electroni-
Use this strategy to find all the objects on the annual list. cally aided scope, binoculars, and astrophotography.

The winners in each category (who saw or imaged
the most objects) received a special gold or silver Ghost
Hunt medal. John Wagoner won the gold medal in the
manual telescope and binocular categories, Larry
Ammann took the gold medal in astrophotography, and
Les Matyas was the winner in the “aided telescope”
category, as he used an electronically aided telescope to
capture 30-second exposures of 82 Ghost Hunt objects
— more than anyone else. “I never dreamed that some-
one would do that,” Lashbrook says.

“While no one got through the entire list,” Lashbrook
says, “we had a great time. Several new members learned
about the sky and observing it. Now they have become
regular members of our club.”

Busting the ghosts

One benefit of the society’s first Ghost Hunt is that they

came up with a plan of attack to help participants search

efficiently and rapidly. Last year, Lashbrook also sug-

gested substitutes for four objects that beginners may

find too difficult to detect. I noted these in parentheses

ABOVE: The Ghost with an asterisk in the “Facing south” group below.
of Saturn Nebula
(NGC 7009) in Due to the COVID-19 pandemic, people Here is the group’s breakdown for attacking the 2020
Aquarius is the 21st
object awaiting across the globe have been confined to their Ghost Hunt. Observers should start with the first object
observers. DANIEL
homes with limited outdoor activities. We listed, then move to the next. All times are local.
VERSCHATSE
amateur astronomers, however, are lucky to have the FACING WEST
OPPOSITE PAGE, night sky to explore, untouched by human
TOP: The Ghost
Puppet Nebula, also concerns. Lockdown or not, this year’s 7:30–8:30 P.M.: M17, M16, M10, M12, M51
known as M16, is the
second target in this October Ghost Hunt — a fun activity that, The society 8:30–9 P.M.: M101, NGC 6572, NGC 6426,
year’s Ghost Hunt. like the Messier marathon, challenges ama- came up NGC 6633, IC 4756, M26, NGC 6712,
teur astronomers to view 109 targets in a M13, NGC 6709, M71, M27, M56, M57,
BOB FERA single night — may just be the medicine we with a plan M92, M72
need to lift our spirits. I originally wrote of attack
BY STEPHEN about the Ghost Hunt, whose targets are to help 9–10 P.M.: NGC 7009, NGC 6934,
JAMES O’MEARA carefully selected from several deep-sky NGC 7006, NGC 6940, NGC 6888,
Stephen is a globe- observing lists, in the October 2009 issue. participants NGC 6826, NGC 6543
trotting observer who search
is always looking Because New Moon occurs October 16 10–11 P.M.: NGC 7293, M2, M15,
for the next great this year, I’ve made adjustments to the origi- efficiently NGC 6992/95, NGC 6960, NGC 6866,
celestial event. nal list, as five objects will be too low to see and rapidly. NGC 6819, Northern Coalsack,
NGC 7000

well: M3, M53, NGC 3242, NGC 4699, and 11 P.M.–12 A.M.: IC 5146, NGC 7008,

NGC 4725. For the 2020 Ghost Hunt, these NGC 7331, NGC 7662, NGC 7789, M52,

have been replaced with M10, M12, NGC NGC 7023

1931, NGC 4656, and NGC 6426. The 2020 Ghost Hunt FACING SOUTH
list, presented in order of right ascension, can be viewed

online at www.Astronomy.com/Ghost2020. 12–1 A.M.: NGC 246, M74, M33, NGC 404, M31,

Texas stargazing M32, NGC 205, NGC 185, NGC 147, NGC 281,
NGC 457, NGC 663, NGC 559

Last October 26, Lloyd Lashbrook and some 25 mem- 1:30–2:30 A.M.: NGC 869/884, M76, NGC 752,

bers of the Texas Astronomical Society of Dallas drove NGC 891, M34, NGC 1023, NGC 1535, M45,

to their dark site in southern Oklahoma with 15 tele- NGC 1333, NGC 1528, NGC 1545, NGC 1501,

scopes to conduct what he “hoped to be the first of many IC 342, NGC 188, NGC 40, NGC 1360

62 ASTRONOMY • SEPTEMBER 2020

2:30–3:30 A.M.: M79, NGC 1999, M42, M43,
NGC 1973/5/7 (*NGC 2017), NGC 2024
(*NGC 1662), M78, NGC 1647, NGC 2163
(*NGC 2169), M1, NGC 2175 (*NGC 2395), M35,
IC 405, NGC 1931

FACING EAST Star Party on Saturday, October 3. It will be a fore- ABOVE: Some 25 members
runner to the main event and will include the Fort of the Texas Astronomical
3:30–4:30 A.M.: M41, NGC 2301, NGC 2237-9, Worth Astronomical Society. “We will just keep Society of Dallas (TAS)
NGC 2261, NGC 2392, M44, NGC 2683, NGC pushing until this thing starts rolling on its own,” participated in the club’s
2419, NGC 2841, M81, M82, M97, M108 Lashbrook says. first Ghost Hunt on
October 26, 2019. From
4:30 A.M.–End: NGC 2467, NGC 2440, NGC 2903, And remember, you’ll find a list of targets updated left to right: Les Matyas
NGC 4236, NGC 4449, NGC 4631, NGC 4656, for 2020 online at www.Astronomy.com/Ghost2020. (overall winner), Gary
Melotte 111, NGC 4565, NGC 3628 As always, send your thoughts and observations to Carter, John Wagoner
[email protected]. I’d really like to know how (gold medal winner in the
A silver Ghost Hunt medal Future plans many Ghost Hunt targets you saw. manual telescope and
was presented to second- binocular categories),
place winners in each “Now that we have had BROWSE THE “SECRET SKY” ARCHIVE AT Mike Planchon, Lloyd
category. Gold medals the first Ghost Hunt,” www.Astronomy.com/OMeara Lashbrook, Larry Ammann
went to first place. TAS Lashbrook says, “enthu- (astrophotography winner),
siasm runs high in the Angela Ellexson, Sean
club” for this month’s Buehrle, and Glenn
— whether it’s solitary, Fitzgerald. TAS
virtual, or social.

The society also
plans to hold a Ghost
Hunt at the Palo Pinto

WWW.ASTRONOMY.COM 63

OBSERVING BASICS collaborate with Astronomy to produce a short video
series, Infinity and Beyond, which covers the cosmos.
Women in
astronomy clubs Why did you join a club?

Female readers share their experiences. Charlotte M. DuPree, a member of the Wehr
Astronomical Society, states emphatically, “Women
Suzie Dills is director Last month, I join astronomy clubs because they have an interest in
of the Hoover-Price highlighted a astronomy and want to learn more, not because they’re
Planetarium in handful of looking to meet men.”
Canton, Ohio. She’s female members in my
also a member of two astronomy club, the A strong passion for the night sky led Suzie Dills —
nearby astronomy Amateur Telescope planetarium director at the Hoover-Price Planetarium
clubs. SHEILA WAYNE Makers of Boston. This in Canton, Ohio — to join two groups, the Cleveland
time around, we hand Astronomical Society and the Cuyahoga Astronomical
Length the mic to women in Association. “I wanted to learn more about the night
restrictions only other astronomy clubs sky and telescopes,” Dills says. Similarly, learning about
who responded to ques- telescopes prompted Sandy Rose of Groton,
allowed for tions I posed in my Massachusetts, to join a local astronomy club after her
snippets of the January column. A summary of their replies follows. husband bought a telescope for her as a birthday gift.
comments used But first, it’s important to note that not all responses
in this column. were positive. In 1993, Doreen McLaughlin (captain, How can clubs increase female membership?
However, I can U.S. Air Force, retired) learned of a public meeting at a
email the full local astronomy club and decided to attend. She was Because women are historically a minority in astronomy
responses to “greeted” at the door by a male member. Upon learning clubs, Dills says, “Perhaps a ladies-only night at the club
that McLaughlin was single and didn’t own a telescope, observatory or telescope night would make women more
anyone who she recalls he “said I could come back when I had a comfortable.” Darekar advises clubs to “plan a meet-
requests them. scope AND a husband — as he (gently but firmly) ing that celebrates and informs others about women’s
pushed me out the outside door and locked it behind achievements in astronomy.” Virginia resident Jackie
BY GLENN CHAPLE me.” McLaughlin has since moved to Colorado. And I O’Neill suggests clubs encourage “members to bring
Glenn has been an greatly hope she has had better luck with astronomy their daughters to meetings and observing sessions.”
avid observer since clubs, and their members, since then.
a friend showed And to avoid losing a potential female member who
him Saturn through What got you into astronomy? ventures to a club meeting or star party for the first
a small backyard time, O’Neill reminds members to “see her as a person
scope in 1963. No surprise here: Anyone can catch the astronomy bug. who enjoys looking into the night sky. Treat her as you
Some learn about the subject while in school. Others would any student eager to learn.”
are introduced to the cosmos by friends or family.
Nancy McGuire, president of the Western Colorado Advice for women considering joining a club?
Astronomy Club, writes, “The sight of Saturn and its
rings through my little Sears refractor when I was a kid Sue French of the Albany Area Amateur Astronomers
got me hooked for life.” Sound familiar? encourages newcomers to “introduce yourself. Tell mem-
bers what you’re interested in. If you’d like help with
Astronomy fever often strikes at a young age. anything, just ask.” We all bring our own unique sets of
Francine Jackson, a member of the Rhode Island knowledge and experience, which is why McGuire sug-
Skyscrapers and frequent contributor to their newslet- gests: “Add your passion and talents for astronomy to the
ter, says, “I’d wanted to be an astronomer since I was 8.” club! Don’t be afraid to give it your personal touch.
Then there’s Ayesha Darekar, who not only joined the Women have great capacity for attention to detail that
Raleigh Astronomy Club in North Carolina as a teen- can enhance a club’s overall environment.”
ager, but also founded a club at her high school.
A common reason given for not joining a club was a
Finally, Abigail Bollenbach, winner of the 2018 perceived lack of knowledge. The good news is that
Horkheimer/Smith Youth Service Award, joined the astronomy clubs aren’t just for those with a doctorate in
Bartlesville Astronomical Society in Oklahoma at age astrophysics. Joyce Jentges of the Northern Cross Science
13. She immediately became involved in the club news- Foundation agrees. “I could[n’t] care less about gravita-
letter and later formed a youth astronomy club. Now, as tional waves and black holes,” she says. “But let me look
she begins college, Bollenbach is finding time to at the planets and deep-sky stuff, [and] I am happy.”
Cristina Montes of Muntinlupa in the Philippines sums
up the feeling shared by many female members of
astronomy clubs: “Just join! We need more of us.”

Questions, comments, or suggestions? Email me at
[email protected]. Next month: Mars is back again!
Clear skies!

BROWSE THE “OBSERVING BASICS” ARCHIVE
AT www.Astronomy.com/Chaple

64 ASTRONOMY • SEPTEMBER 2020

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BINOCULAR UNIVERSE released the Palermo Star Catalogue. When the catalog’s
second edition appeared in 1814, the stars Alpha and

Beta Delphini had been named Sualocin and Rotanev.

How did that happen? Nineteenth-century English

A dolphin’s tale astronomer Thomas Webb unraveled the mystery. It
turns out Piazzi’s assistant, Niccolò Cacciatore, oversaw
the second edition’s creation and publication. Translated

Tiny Delphinus holds some sweet binocular treasures. into Latin, Niccolò Cacciatore becomes Nicolaus Venator.
Spell his Latinized name backward and what do you get?

Sualocin and Rotanev. Cacciatore’s little practical joke

has endured for more than two centuries.

Delta Delphini, the southeastern corner, is an unusual

spectroscopic binary system. Both white-hot suns com-

bine characteristics of a type A star with that of a type F.

Closing the diamond is Gamma Delphini, at the

northeastern corner. Gamma is a striking binary star

system through amateur telescopes, pairing an orange

4th-magnitude primary star with a 5th-magnitude pale

yellow companion, separated by 10". That’s too close to

resolve through most binoculars. I can sense Gamma’s

duality through my 25x100s, but cannot split them

cleanly. I would be interested in receiving your reports

on resolving Gamma through high-power binoculars.

Shift your attention 2° south-southwest of Job’s Coffin

to Theta (θ) Delphini and the surrounding bevy of

fainter points. Webb was also first to draw attention to

The small This month, we find Delphinus the Dolphin this region in his 1859 Celestial Objects for Common
constellation swimming in an empty portion of the sky, east Telescopes. He noted that Theta was nestled “in a beauti-
Delphinus has a of the Milky Way’s plane. Ranking only 69th ful field.” My friend the late John Davis interpreted
distinctive shape in size among the 88 sanctioned constellations, Webb’s “beautiful field” more inventively, connecting
and holds a multitude Delphinus is drawn from just five 4th-magnitude stars. the stars into a small asterism he called the bucking
of unusual stars. bronco. His creative mind saw orange Theta as the

BILL AND SALLY FLETCHER

Despite their dimness, Delphinus stands out surpris- bronco’s saddle. To its east, a triangle of faint stars traces

ingly well, even under the veil of suburban light pollu- the steed’s raised leg, while a trail of faint stars to the

tion. That’s likely because of the distinctive pattern they southwest completes the horse’s form. The rider is an arc

form. Four of the stars — Alpha (α), Beta (β), Gamma of 10th-magnitude stars curving north from Theta.

(γ), and Delta (δ) Delphini — create a sharply pointed, Finally, extend a line from Alpha to Delta and con-

diamond-shaped asterism known as a lozenge. All four tinue southeastward for just over 8° to a delightful

fit nicely into the fields of most binoculars. double star, Gamma Equulei. Turn your

Measuring 1.3° by 2.7°, this four-star Delphinus is binoculars its way and you’ll immediately
asterism is also known as Job’s Coffin. The notice that 5th-magnitude Gamma is joined

origin of that rather macabre nickname is drawn from by a 6th-magnitude star to its southeast.
lost to history, but there’s no question that just five This second sun is cataloged as 6 Equulei. If
the four-star sarcophagus is interesting to you have keen color perception, Gamma
study through binoculars. 4th-magnitude may look slightly yellowish, while 6 is white.
stars. Both are separated by 6', making them easily
Its northwestern corner, Alpha, properly

named Sualocin, is a blue main sequence star resolvable through the smallest pocket

with a surface temperature about twice that binocular. Their pairing is purely circum-

of our Sun’s. Its color is apparent through binoculars, stantial, however. Gamma is 118 light-years away, while

especially after slightly defocusing the view. 6 Equ is almost four times farther out. Few observers

Compare Alpha to Beta Delphini, the southwestern ever notice Gamma because it lies in the obscure con-

corner. Also known by the proper name Rotanev, Beta stellation Equuleus the Little Horse. Were it more

is a closely set pair of yellow-white subgiant stars. prominently positioned in the sky, it would surely be a

Although far too close to resolve through binoculars seasonal binocular favorite.

BY PHIL — or most amateur telescopes, for that matter — those Comments, suggestions? Contact me through my
HARRINGTON stars pool their efforts to display a soft yellowish tint. website, philharrington.net. And remember, two eyes
Phil is a longtime are better than one.
contributor to The origin of these stars’ curious proper names dates
Astronomy and the back only to the 19th century. In 1803, two years after BROWSE THE “BINOCULAR UNIVERSE” ARCHIVE AT
author of many books. he discovered the first asteroid (now classified as a dwarf www.Astronomy.com/Harrington
planet), Ceres, Sicilian astronomer Giuseppe Piazzi

66 ASTRONOMY • SEPTEMBER 2020

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A S K A S T R O Astronomy’s experts from around the globe answer your cosmic questions.

RELAY COMMUNICATIONS Queqiao are balanced, meaning Queqiao will
relay permanently remain in that location
Earth satellite because gravity isn’t tugging it away.
Moon
L2 halo orbit Furthermore, Queqiao is in a halo
orbit, which means it’s actually orbit-
L2 ing the L2 point itself. While Queqiao
always remains on the opposite side of
Lagrangian the Moon from Earth, its orbit sweeps
point it out far enough from behind the
Moon’s limb that signals can then
travel between the spacecraft and our
planet. So, any time researchers want
to communicate with Chang’e-4, they
send a signal to the satellite, which
then relays the information to the
lander — and vice versa.

Alison Klesman
Senior Associate Editor

Chang’e-4 Messages Q I HOW DO PLANETS DEVELOP AN
communicates from the ATMOSPHERE?
with Earth via a farside Shobha Kaicker
relay satellite Mississauga, Ontario
named Queqiao, Q I HOW IS IT POSSIBLE FOR
whose orbit around THE CHANG’E-4 LANDER TO A I Planets and their atmospheres come from the
pthoeinEtaarltlho-wMsoitotnoL2 COMMUNICATE WITH EARTH FROM same material as their parent star, which forms
speak with both the THE FARSIDE OF THE MOON, WHILE from a nebula of dust and gas. After the new sun ignites,
lander and mission THE APOLLO ASTRONAUTS COULD NOT excess material that didn’t make it into the star instead
scientists back on COMMUNICATE WITH NASA WHILE THEY forms a disk around it. Planets, asteroids, and comets
Earth. ASTRONOMY: ROEN KELLY WERE ORBITING ON THE FARSIDE? later condense from that disk.

James P. Collins Based on computer modeling of the planet-formation
Rochester, New York process, astronomers believe that giant worlds — such
as Jupiter, Saturn, Neptune, and Uranus in our solar
system — likely pull in gas directly from the surround-
ing nebula to swaddle them. This is why our giant
planets have atmospheres that are largely hydrogen and

A I When Apollo astronauts circled the Moon, Planets condense from the gas and dust left over after the birth
communications were cut off with Earth every of their parent star. Larger planets, such as gas giants, then pull
time the command module passed behind the Moon. more gas from their surroundings into thick atmospheres, as
This is because the Moon itself blocks radio signals, seen in this artist’s impression of a forming gas giant in the disk
preventing communication when it comes between around the star HD 100546. ESO/L. CALÇADA
Earth and any spacecraft.

But mission scientists have maintained constant
contact with Chang’e-4, located on the lunar farside in
Von Kármán crater within the larger South Pole-Aitken
Basin. They communicate with the lander via a relay
satellite, Queqiao, which orbits a point called the Earth-
Moon L2 Lagrangian point. L2 is a point about
40,390 miles (65,000 kilometers) beyond the Moon. It is
one of five Lagrangian points where gravitational forces

68 ASTRONOMY • SEPTEMBER 2020

helium, the two most common elements in the Sun and THE SUN’S EXPANDING Habziotnaeble
the nebula in which it formed. Terrestrial (rocky) plan- HABITABLE ZONE
ets may also pull in surrounding gas early in their for-
mation. But because these planets are smaller and less Current Sun Mercury Uranus
massive, they can’t pull in as much — or as quickly — as 4.6 billion Jupiter
the giants. And these early atmospheres likely aren’t the years Earth
same atmospheres smaller planets have today. Neptune
Venus Saturn
That’s because, over time, a young star grows brighter
and hotter. Its increasing radiation blows the light- Mars
weight hydrogen and helium from the atmosphere of
any planet without enough mass (and, thus, gravity) to Habzitoanbele
hold onto it. In our solar system, this is how the inner
planets lost their initial atmospheres. Meanwhile, the Red Giant Sun Earth Uranus
outer planets — both farther away and more massive 12.5 billion years Mars Jupiter
— held onto theirs. Astronomers believe the inner
planets later developed secondary atmospheres of Neptune
heavier molecules, such as carbon dioxide and water, Saturn
from outgassing that occurred through events such as
volcanic activity. Additionally, theories suggest that A star’s habitable zone, or the region around the star where SEND US YOUR
comet and asteroid impacts could have brought volatiles temperatures are warm enough for a planet’s surface to sustain QUESTIONS
— particularly water — that contributed to our inner liquid water, depends on the star’s temperature and brightness.
planets’ atmospheres over time. Both outgassing and As a red giant, our Sun will expand and heat up, forcing its Send your
impacts likely also occur in other star systems, likewise current habitable zone, which now encompasses Earth, outward. astronomy questions
giving smaller, terrestrial planets their atmospheres. via email to askastro@
ASTRONOMY: ROEN KELLY astronomy.com, or
Alison Klesman write to Ask Astro,
Senior Associate Editor been pumped up by their star’s intense radiation. So, P.O. Box 1612,
our own Jupiter’s fate is far from certain. Waukesha, WI 53187.
Q I HOW FAR WILL THE SUN EXPAND Be sure to tell us
DURING ITS TRANSITION TO A The inner realm’s doomsday will bring a brief new your full name and
RED GIANT? HOW MANY PLANETS WILL dawn to the outer solar system. Saturn’s moon Titan, where you live.
BE ENGULFED, AND WHAT — IF ANY — the only known satellite with a significant atmosphere, Unfortunately, we
EFFECTS WILL THE EXPANSION HAVE ON should keep its dense shroud. It could enjoy several cannot answer all
THE GIANT PLANETS’ ATMOSPHERES? hundred million years of potentially habitable condi- questions submitted.
tions with liquid oceans of water-ammonia, simulations
Jacob Bertin show. The environment may even resemble early Earth.
South Williamsport, Pennsylvania Eventually, Pluto and its cousins in the Kuiper Belt —
plus Neptune’s moon Triton — could be the most valu-
A I Roughly 5 billion years from now, the Sun will able real estate in the solar system. When the Sun turns
exhaust the hydrogen fuel in its core and start into a red giant, the temperatures there will be equiva-
burning helium, forcing its transition into a red giant lent to those in tropical locales on Earth today, such as
star. During this shift, its atmosphere will expand out Miami Beach, according to Southwest Research
to somewhere around 1 astronomical unit — the cur- Institute astronomer S. Alan Stern.
rent average Earth-Sun distance. This means the Sun
will gradually engulf Mercury, Venus, and likely Earth. Eric Betz
Any surviving earthlings will have long since fled the Astronomy contributor
brightening Sun — or, as some scientists recently sug-
gested, moved the planet itself to a more sanguine orbit.

The atmospheres of gas giant planets like Jupiter and
Saturn will gradually erode under the increased radia-
tion from the Sun. However, astronomers have found a
number of gas giant exoplanets orbiting close to their
red giant stars. These so-called hot Jupiters have man-
aged to hold onto their atmospheres. Some of them even
have enormous, puffy atmospheres that appear to have

WWW.ASTRONOMY.COM 69

READER GALLERY

Cosmic portraits

Chamaeleon Cederblad 111 NGC 3620
Infrared Cederblad 112
Nebula

Cederblad 110

1 2

1. WHEN THE DUST SETTLES
This amazing region of dark and
reflection nebulosity lies in the
far-southern constellation
Chamaeleon. Several of the
objects are included in a catalog
of 330 bright galactic nebulae,
compiled by Swedish astronomer
Stefan Cederblad in 1946.
• Nicholas Clarke

2. THE EIGHTH SISTER
Venus passed in front of the
Pleiades star cluster (M45), also
known as the Seven Sisters, on
the evening of April 3, 2020.
Although M45 is one of the
closest star clusters, it was still
more than 45 million times as far
away as Venus during this lineup.
• John Chumack

3

70 ASTRONOMY • SEPTEMBER 2020

3. BY ANY OTHER NAME
G255.8+10.9 is a faint one-
sided planetary nebula in
the constellation Pyxis the
Compass. The planetary
is surrounded by the red
emission nebulosity of
Sharpless 2–312. The
photographer captured
28.5 hours of exposures
through a 20-inch telescope
to create this image.
• Don Goldman

4. LET FREEDOM REIGN
The Statue of Liberty Nebula
(NGC 3576) is a huge
star-forming region in the
constellation Carina the Keel.
The loops form when strong
stellar winds — radiation and
particles emitted from nearby
stars — move the gas in the
region into rounded shapes.
• Matt Dieterich

5. CELESTIAL ACT
The Zhuhai Grand Theatre,
built on the shore of the
South China Sea, was the
foreground for the annual
Geminid meteor shower
December 12, 2019.
Unfortunately, the Full Moon
also intervened, but the
camera was still able to
capture several meteors.
• Likai Lin

4

5

WWW.ASTRONOMY.COM 71

READER GALLERY

6. BEFORE I GO 6
To create this image of fading
Comet C/2019 Y4 (ATLAS),
this photographer captured
2 hours 35 minutes of
exposures through a
Celestron Compustar C14
equipped with a Starizona
LF reducer/corrector for
an f/7.5 focal ratio. He shot
from Portland, Oregon, from
4h45m UT through 7h16m UT
on April 8, 2020. • Rodney
Pommier

7. CAULDRON OF COLOR
The Witch Head Nebula (IC
2118) lies some 900 light-years
away in the constellation
Eridanus the River. It glows
blue because it scatters and
reflects light from Rigel (Beta
[β] Orionis). It’s not alone,
though. As you can see,
many other nebulae lie in
this fascinating region. Note
that this image has been
flipped so the Witch Head
appears right-side up.
• Adam Block/Steward
Observatory/University
of Arizona

7

72 ASTRONOMY • SEPTEMBER 2020

8. I’M SAILING AWAY
The Sailboat Cluster (NGC
225), a name given to this
open star cluster by longtime
Astronomy contributor
Rodney Pommier, lies in the
constellation Cassiopeia the
Queen. Also visible in the
same region is the blue
reflection nebula van den
Bergh 4 and the dark nebula
LDN 1291 (which lies to the
lower left of vdB 4).
• David Wills

9. PENUMBRAL PASSAGE
On January 10, 2020, the
Moon passed through Earth’s
penumbra (its lighter, outer
shadow). These 1/320-second
exposures through the same
equipment show the Moon
at mid-eclipse (left) and
immediately after the eclipse
was over. • Ken Harrison

10. PICTURESQUE SWIRL
NGC 3184 is a face-on spiral
galaxy in the constellation

8 Ursa Major the Great Bear.
It has been host to five
supernovae during the past
century. NGC 3184 lies some
40 million light-years from
Earth. • John Vermette

9

SEND YOUR IMAGES TO:
Astronomy Reader Gallery,
P.O. Box 1612, Waukesha,
WI 53187. Please include
the date and location of the
image and complete photo
data: telescope, camera,
filters, and exposures.

10 Submit images by email to
readergallery@
astronomy.com.

WWW.ASTRONOMY.COM 73

BREAKTHROUGH

PEEKING BEHIND A DUSTY VEIL

While English astronomer John Herschel was scanning northwestern Centaurus with his 18.7-inch telescope in April 1835,
he came across a faint smudge that he cataloged as NGC 3749. Little could he imagine that more than 180 years later, a
94.5-inch instrument lofted above Earth’s obscuring atmosphere would render this edge-on spiral galaxy in such stunning
detail. The Hubble Space Telescope shows NGC 3749’s dusty disk, which conceals much of the object’s other features from
our view. But spectra of the galaxy reveal several strong emission lines, suggesting it harbors large numbers of hot young
stars. Hubble captured this scene across 135 million light-years of intergalactic space. ESA/HUBBLE AND NASA, D. ROSARIO ET AL.

74 ASTRONOMY • SEPTEMBER 2020



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IC 405 Dancing Blue by Tony Hallas with EdgeHD 1100 Crab Nebula by Andre Paquette with EdgeHD 1400

SOUTHERN SKY BY MARTIN GEORGE

November 2020

A feast of evening planets

November features right of the Archer’s prominent Although Venus lies a healthy not make it into the official list
exquisite evening views Teapot asterism. 31° west of the Sun in mid- of 88 and have disappeared
of three outer planets. Mars November, it stands only 6° from use.
likely will draw the most atten- Any telescope can deliver high an hour before sunrise.
tion because it reached a favor- stunning views of Jupiter. The You can blame the shallow However, some of the ones
able opposition just last month gas giant offers a fine array of angle of the ecliptic — the we know today have names that
and remains near its peak. The colorful atmospheric features apparent path of the Sun across were shortened from their orig-
Red Planet lies high in the and an obvious polar flatten- our sky that the planets follow inal identities. Good examples
northeast as darkness falls and ing. (The world’s rapid rotation closely — to the eastern hori- include some of those 18th-
outshines every other object in and gaseous content means that zon before dawn this time of century French astronomer
the area. It stands out even its polar diameter is 6 percent year. Venus’ elongation from Nicholas Louis de Lacaille
more thanks to its distinctive less than its equatorial diam- the Sun translates mostly into added. Famed English astrono-
ruddy hue. eter.) And you can’t miss distance along the horizon and mer John Herschel suggested
Mars resides among the Jupiter’s four bright moons not altitude above it. A tele- shortening many of these
much fainter background stars unless, of course, one or more scopic view proves disappoint- names in a remark published in
of Pisces the Fish. It drifts happens to be hidden in front ing: The planet’s disk appears Monthly Notices of the Royal
slowly westward against this of or behind the planet. only 12" across and 85 percent Astronomical Society in 1844.
backdrop during November’s lit at midmonth.
first half, pauses briefly on the Jupiter drifts slowly east- If you look high in the east
15th, and then reverses course ward against the starry back- Mercury reaches greatest early on a November evening,
and heads eastward. drop, putting it on an apparent elongation November 10, when you’ll see the constellation
If you follow Mars all collision course with Saturn. it lies 19° west of the Sun. Lacaille called L’Atelier du
month, you’ll no doubt notice The distance between the two Unfortunately, it also suffers Sculpteur, or the Sculptor’s
it growing dimmer as it moves worlds shrinks from 5° to 2° from the ecliptic’s inclination Workshop, which we now call
away from Earth. It shines at this month, a harbinger of their to the horizon and will be Sculptor. In the interim, this
magnitude –2.1 on the 1st but spectacular conjunction in late difficult to spot from mid- star group also has been called
appears less than half as bright December. Although it appears southern latitudes. Officina Sculptoria and
(magnitude –1.2) on the 30th. 12 times fainter than Jupiter, Apparatus Sculptoris.
A telescope reveals similar Saturn’s magnitude 0.6 glow A penumbral lunar eclipse
distance-related changes: The bests all of Sagittarius’ stars. takes place November 30. At its The constellation Antlia the
planet’s diameter shrinks from peak at 9h43m UT, 86 percent Air Pump, which doesn’t clear
20" to 15" during November. The view of the ringed of the Moon’s diameter will be the horizon until after mid-
Thankfully, this is still plenty planet through a telescope has within Earth’s lighter penum- night in November, is another
big enough to show consider- few, if any, equals. The planet’s bral shadow. Viewers in west- good example. Lacaille origi-
able detail. Expect to see sev- yellowish globe measures 16" ern South America, the Pacific nally called it la Machine
eral dusky surface markings in across in mid-November while Ocean, New Zealand, and east- Pneumatique, and it was later
addition to the south polar cap, the rings span 36" and tilt 22° ern Australia should see a given the Latin name Machina
which conveniently tips in our to our line of sight. Take a few dusky shading across the Pneumatica.
direction this month. minutes to look for the shadow Moon’s northern half.
Swing your gaze to the west- of Saturn’s disk falling on the Much farther south and
ern sky and you can’t miss rings. It appears as a narrow The starry sky not far to the left of the South
Jupiter. The giant planet shines gap on the rings’ farside just Celestial Pole in November’s
at magnitude –2.1, brighter east of the planet’s limb. As many amateur astronomers evening sky, we have Reticulum
than any other point of light in know, 88 constellations cover the Reticle. Lacaille called this
the evening sky. Jupiter lies in Around the time that Mars the sky with no gaps or over- group le Reticule Rhomboide,
eastern Sagittarius, to the upper sets, Venus pokes above the laps. Still, a number of cultures and he fashioned it from stars
eastern horizon. The brightest around the world recognize that reminded him of the
planet shines at magnitude –3.9 many other star groups. And rhomboidal-shaped reticle of
and appears unmistakable some constellations of yore did four lines he used in his celes-
against the morning twilight. tial observations.

STAR DOME S

HOW TO USE THIS MAP TARUISATNRGAULLEU M MUSCA 2

This map portrays the sky as seen TELESCOPIUM APUS CHAMAELEON
near 30° south latitude. Located NGC 6397
inside the border are the cardinalA UCSOTRROANLAI S ARA NGC 104 L A N S SCP
directions and their intermediate O CTANS
points. To find stars, hold the mapSW INDUS MENSA 20N7G0C
overhead and orient it so one of PAVO
the labels matches the direction HYDRUS
you’re facing. The stars above
the map’s horizon now match MICROSCOPIUM SMC RETICULUM
what’s in the sky. S A G I T TA R I U S LMC

The all-sky map showsSaturn TUCANA Achernar OROLOGIUM
how the sky looks at:Jupiter
11 P.M. November 1 GRUS
10 P.M. November 15
9 P.M. November 30CAPRICORNUS PISCIS Fomalhaut SCULPTOR PHOENIX
Planets are shown AUSTRINUS
W at midmonth

MAP SYMBOLS SGP
NGC 253
Open cluster
Globular cluster A Q UA R I U S CETUS
Diffuse nebula
Planetary nebulaDELPHINUS E Q U U L E U S M15 Mira
Galaxy
Mars
STAR
MAGNITUDES Enif

Sirius PISCES UranusPath of th
0.0 3.0 ARIES
1.0 4.0 PEGASUS
2.0 5.0
NW M33
STAR COLORS
TRIANGULUM
A star’s color depends M31
on its surface temperature.
ANDROMEDA
The hottest stars shine blue
N
•• Slightly cooler stars appear white
• Intermediate stars (like the Sun) glow yellow
• Lower-temperature stars appear orange
• The coolest stars glow red
• Fainter stars can’t excite our eyes’ color

receptors, so they appear white unless you
use optical aid to gather more light

BEGINNERS: WATCH A VIDEO ABOUT HOW TO READ A STAR CHART AT
www.Astronomy.com/starchart.

CARINA NOVEMBER 2020 SAT.
NGC 33
SUN. MON. TUES. WED. THURS. FRI.

VELA SE 1 234567

V 8 9 10 11 12 13 14

R PICTO 15 16 17 18 19 20 21 ILLUSTRATIONS BY ASTRONOMY: ROEN KELLY
NGC 2516
NGC 2477 22 23 24 25 26 27 28
COLUMBA
DORADO PUPPIS M41 29 30
Canopus CANIS MAJOR
Note: Moon phases in the calendar vary in size due to the distance
CAELUM M47 from Earth and are shown at 0h Universal Time.
MONOCEROS
LEPUS Sirius CALENDAR OF EVENTS
E
ERIDANUS 1 Asteroid Flora is at opposition, 7h UT
Rigel ORION 3 Mercury is stationary, 8h UT
M42 Betelgeuse 8 Asteroid Juno is in conjunction with the Sun, 9h UT

Aldebaran Last Quarter Moon occurs at 13h46m UT
10 Mercury is at greatest western elongation (19°), 17h UT
he Sun (ecliptic) TAURUS M1 12 The Moon passes 3° north of Venus, 21h UT
Pleiades 13 The Moon passes 1.7° north of Mercury, 21h UT
NE 14 The Moon is at perigee (357,837 kilometers from Earth), 11h43m UT
15 New Moon occurs at 5h07m UT
Algol PERSEUS
Venus passes 4° north of Spica, 13h UT
Mars is stationary, 19h UT
17 Leonid meteor shower peaks
19 The Moon passes 2° south of Jupiter, 9h UT
The Moon passes 3° south of Saturn, 15h UT
22 First Quarter Moon occurs at 4h45m UT
23 The Moon passes 5° south of Neptune, 12h UT
25 The Moon passes 5° south of Mars, 20h UT
27 The Moon is at apogee (405,894 kilometers from Earth), 0h29m UT
The Moon passes 3° south of Uranus, 17h UT
29 Neptune is stationary, 9h UT
30 Full Moon occurs at 9h30m UT; penumbral lunar eclipse