Seeing is Believing: Hidden Galaxies Revealed

Journal of the Amateur Astronomers Association of New York

March 2015 Volume 63 Number 3; ISSN 0146-7662

Like driving with a dirty windshield, Andrew Baker

tries to peer at what’s behind clouds of dust in our uni-

verse. Sometimes, the dust hides entire galaxies. The

Rutgers University astrophysicist spoke about the phenome-

non of hidden galaxies in the distant universe on Feb 6 at the

American Museum of Natural History, the latest in AAA’s

free, monthly lecture series.

Baker began by thanking the U.S. taxpayers in the audi-

ence “for willingly or unwillingly” supporting his research,

which is funded by the National Science Foundation, on the

Green Bank Telescope in West Virginia. The 100-meter-

wide dish is the world’s largest, fully steerable telescope, part

of the National Radio Astronomy Observatory (NRAO).

Interstellar dust is made of carbon, silicon and other

elements produced in the outer envelopes of dying red stars.

The dust absorbs visible light from stars and reradiates the

light in the far infrared spectrum, or long wavelength radia-

tion. When astronomers look at a portion of the sky, the

missing optical light is a signpost for dust. “We know what’s

there – dust – because we know what’s missing – light from

stars,” said Baker.

He offered up slides of

some well-known examples:

the iconic shape of the Horse-

head Nebula (Barnard 33) is the

result of huge dust clouds in

front of ionized gas; the Trifid

Nebula (M20) is bisected by

large regions of dust; and the

Whirlpool (M51) and Black Eye

(M64) Galaxies have extremely

large dust lanes in their spiral

structures.

“Can dust hide an entire

galaxy?” Baker asked. He then quickly replied to his own

question, “Y es! If all the light is missing, we might not even

realize there is a galaxy at all.”

So how do you find these hidden galaxies? “When CO

is Our Friend,” answered Baker’s next slide. Most associa-

tions with that molecule are negative, and although carbon

monoxide (CO) is dangerous to humans on Earth, radio as-

AAA Lecture (cont’d on Page 4)

By Stan Honda Richard Brounstein

Diving in: Exploring Europa’s Subsurface Ocean

WHAT IF???

THIS MONTH: AAA Lecture on Mar 6 and NASA Sun/Earth Day at AMNH on Mar 21!

AAA LECTURE SERIES

NASA and ESA are

planning a trip to Europe, er

Europa, that is – not the

Earth continent, but the icy

moon of Jupiter that hides a

salty, liquid water ocean be-

neath its surface. This feature

makes the outer Solar System

body a very special place, one

of the very promising loca-

tions where non-Earth life

forms may actually exist.

The American and Euro-

pean (perfect!) space agencies have announced a joint mis-

sion called JUICE (JUpiter ICy moons Explorer), which will

launch in 2022 and arrive in orbit around Jupiter in 2030.

During flybys of several Jovian moons, the probe will per-

form detailed reconnaissance of Europa to gain more infor-

mation about it. The mission will collect high resolution

images and study its surface features and processes. Europa’s icy crust has been subject to continuous resur-

facing by tectonic and thermal processes over tens of mil-

lions of years. Patterns of ice cracks, ridges, and displace-

ment show signs of surface stress, and tidal flexing due to

Jupiter’s gravity keeps Europa’s water warm enough to be

liquid. Material is exchanged between the subsurface ocean

and the ice crust in continuous processes. Studying Europa’s

surface is an important first step to exploring its ocean and

the life forms that may reside beneath. Now, we have to fig-

ure out the best way to break the ice. Twenty years ago, the NASA spacecraft Galileo made a

flyby of Europa and sent back to Earth the first data to sug-

gest a 60-mile deep subsurface ocean. Since then, it has been

a dream of astronomers and astrobiologists to explore it. We

know here on Earth that where there is liquid water, there is

life. So, it is only logical to suspect that Europa’s salty ocean

harbors life too. But even if we manage to make our way

there on the nearly 400 million-mile trip, going for a dip will

be a huge challenge. We don’t know exactly the depth of

Europa’s ice layer – it could be tens of kilometers thick. So,

we can’t just drill a hole and go fishing. But, there may be a

Ocean Exploration on Europa (cont’d on Page 4)

NASA

A liquid water ocean under the icy surface of Jupiter’s moon Europa

may be 60 miles deep.

NASA

For 2015, International Year of Light, Chandra X-ray Observa-tory released new pics like this one of Whirlpool Galaxy M51.

NAO

The Horsehead Nebula’s shape is formed by interstellar dust clouds in front of ionized gas.

2

March’s Evening Planets: Mars will be visible for

about an hour after sunset in Pisces the Fish. Venus will be

visible for about 3 hours after sunset moving from toward

Taurus the Bull. Uranus will also be in Pisces for about one

hour after sunset in the first half of the month. Bright Jupi-

ter is found in Cancer the Crab all night.

March’s Evening Stars: The Winter Triangle will be

up in March until 11:00 PM with Sirius, the brightest star

viewed from Earth, in Canis Major the Great Dog; Betel-

geuse in Orion the Hunter; and Procyon in Canis Minor the

Small Dog. Spot Capella in Auriga the Charioteer, Aldeber-

an in Taurus the Bull, Arcturus in Bootes the Herdsman, and

bright Castor and Pollux in Gemini the Twins. Also find the

stars of constellations Cassiopeia, Perseus, Cepheus, Draco,

Virgo, Leo, Cancer, Corona Borealis, and the two Dippers

during the month.

March’s Morning Planets: Jupiter will linger in Can-

cer the Crab until dawn. Saturn be up in Scorpius the Scorpi-

on after midnight and will stay until sunrise. Mercury is be-

tween Capricornus the Seagoat and Aquarius the Water Bear-

er during the first half of March for about an hour before

sunrise. Later in the month, Neptune will be in Aquarius

shortly before sunrise. Dwarf planet Pluto will be in Sagitta-

rius the Archer a couple of hours before sunrise.

March’s Morning Stars: Spot the Summer Triangle

around 3:00 AM, rising earlier every night, formed by Vega

in Lyra the Harp, Deneb in Cygnus the Swan, and Altair in

Aquila the Eagle. Look for reddish Antares in Scorpius the

Scorpion, Arcturus in Bootes the Herdsman, and Spica in

Virgo the Virgin, along with the stars of constellations Leo,

Lyra, Hercules, Libra, Corona Borealis, Cassiopeia, Cepheus,

Draco, and the two Dippers.

Mar 3 Jupiter is 5° north of the Moon (morning)

Mar 5 Full Moon at 1:05 PM EST (smallest of 2015)

Moon at apogee (252,515 miles from Earth)

Mar 8 Daylight Saving Time begins

Mar 13 Last Quarter Moon at 1:45 PM

Mar 19 Moon at perigee (222,190 miles from Earth)

Mar 20 New Moon at 5:35 AM

Vernal Equinox at 6:45 PM

Total Solar Eclipse (not visible in the US)

Mar 21 Mars is 1° north of the Moon (at sunset)

Saturn is 2° south of the Moon (morning)

Mar 22 Moon pairs with Venus after sunset

Mar 27 First Quarter Moon at 3:45 AM

Times given in EDT, unless noted.

WHAT’S UP IN THE SKY

March “Skylights”

March 2015

In 2006, the International Astronomical Union (IAU)

changed Pluto’s classification to a dwarf planet, defined as: "a

celestial body that (a) is in orbit around the Sun, (b) has suffi-

cient mass for its self-gravity...so that it assumes a hydrostatic

equilibrium (nearly round) shape, (c) has not cleared the neigh-

bourhood around its orbit, and (d) is not a satellite.” Dwarf plan-

ets are tiny, dim, and often in far-flung orbits, making them

tough to find. Scientists estimate that dozens remain undiscov-

ered. Here are the five most recognized.

Pluto was discovered

by Clyde Tombaugh in

1930 and named for the

Roman god of the under-

world (Hades, in Ancient

Greece). The 1,455 mile-

wide body has an extremely

elliptical orbit in a different

plane than the eight planets

of our Solar System. It orbits the Sun at an average distance of

39.3 au, taking 248 Earth years to complete a lap. Its five moons

are named for elements of underworld mythology: Charon, Nix,

Hydra, Kerberos, and Styx. The largest, Charon, is nearly equal

in size to Pluto, forming a double system. NASA’s New Hori-

zons spacecraft is scheduled to reach Pluto in July 2015. It was

still the ninth planet when the mission launched in early 2006.

Ceres is the smallest of the dwarf planets at 590 miles

wide, but the largest object in the Asteroid Belt between Mars

and Jupiter. Discovered in 1801, it was named for the Roman

grain goddess (Demeter, to the Greeks). It is nearest at only 2.8

au from the Sun and completes one orbit in 4.6 Earth years. It is

thought to be an icy protoplanet, the only one not found in the

Kuiper Belt. NASA’s Dawn mission will arrive at Ceres this

month for our first study of a dwarf planet.

Haumea, discovered in 2003, has an elongated shape with

a rocky interior, covered by a thin, icy crust. It is named for the

Hawaiian goddess of fertility, and its moons are named for her

daughters Hi‘iaka and Namaka. Haumea is about as wide as

Pluto at 1,200 miles, but it is 1/3 as massive. Haumea averages

43.2 au in its 283 Earth-year orbit. It completes one full rotation

in less than four hours, making it one of the fastest-spinning bod-

ies in the Solar System.

Makemake, a plutoid (orbiting beyond Neptune), was

discovered ten years ago and is named after the fertility god of

the native people of Easter Island. Its surface is thought to be

composed of frozen methane, ethane, and nitrogen. It is about

3/4 as big as Pluto and at 45.7 au from the Sun, it completes one

orbit every 310 Earth years.

Eris, another plutoid, was found in January 2005 and

briefly considered our tenth planet. It was demoted by the IAU

with Pluto. It is named for the Greek goddess of chaos and has

one known moon named for her daughter, Dysnomia, the god-

dess of lawlessness. Eris is similar in size to Pluto but about

25% more massive. It has a highly elliptical orbit at an average

distance of 67.8 au, which takes 557 Earth years to complete.

Sources: IAU; Encyclopedia Britannica; nasa.gov; space.com.

Follow veteran sky watcher Tony Faddoul each month, as he points our minds and our scopes toward the night sky.

AAA Observers’ Guide

By Tony Faddoul

Pluto and the Dwarf Planets

3

March 2015

Seen in Space Citizen Scoobies Investigate a Spitzer Mystery and

Thar She Blows! NuSTAR & XMM-Newton See Black Hole Wind

Zooniverse.org is a

citizen science website

where anyone can help sci-

entists classify data. Vol-

unteers on The Milky Way

Project found what they

dubbed “yellowballs” in im-

ages taken by the Spitzer

Space Telescope. They had stumbled upon “a new way to

detect the early stages of massive star formation,” said

Charles Kerton, co-author of a new study. “The simple ques-

tion of ‘Hmm, what’s that?’ led us to this discovery.” They’re

not really yellow – its just the color their infrared wave-

lengths are assigned, where green and red overlap. They oc-

cur mainly along the rim of green bubbles of organic mole-

cules that are blasted out by a massive newborn star. Inside

the bubbles is dust, red when warmed by the star. Analysis

reveals that this new class of object formed before the green

bubbles – representing an earlier phase of star birth. Their

presence suggests the massive new stars are causing more

starbirths, a phenomenon called triggered star formation.

NASA and ESA are

teaming up to figure out just

how powerful supermassive

black holes really are. Their

space telescopes NuSTAR and

XMM-Newton view comple-

mentary high and low energy

parts of the X-ray spectrum.

Together, they observed “nearby” PDS 456, a luminous qua-

sar powered by a black hole formed 10 billion years ago, and

found that its 223 million mph radiation is blowing out not as

a beam, but in all directions. "For an astronomer...PDS 456

is like a paleontologist being given a living dinosaur to study,"

said Daniel Stern of NASA. As the black hole feeds, ionized

particles are forced out of its accretion disk, inhibiting star

formation and regulating its galaxy’s growth. Having meas-

ured the wind’s speed, shape, and size, scientists can now

determine the black hole’s strength. AMW Source: nasa.gov

Down to Earth Forward Progress with a Backward Glance

NASA’s Earth Sciences Division has had a busy

year, launching five missions, two in the past month alone

– Soil Moisture Active Passive (SMAP) and Deep Space

Climate Observatory (DSCOVR). SMAP will make high-

resolution global maps of the Earth’s soil moisture to track

water availability and identify trends around the planet. It

will help improve weather forecasts, monitor droughts, pre-

dict floods, gauge climate cycles, and hopefully, guide policy

decisions. A major impact of climate change will be its soci-

etal effects on water supply, especially for food production.

Meanwhile, renamed DSCOVR, the Earth observatory

first proposed by Vice President Al Gore in 1998 called Tria-

na finally launched last month, after sitting in storage during

the Bush administration. The satellite was originally intend-

ed to gather data about global warming and also raise Earth

awareness by taking a live image of

the planet to be made available to the

public on the internet. Redefined for

funding purposes by President

Obama, DSCOVR will primarily

monitor solar wind in real-time and

measure radiation, but it will still

image the sun-lit side of the Earth,

monitoring ozone, aerosols, cloud

dynamics, land, and vegetation.

AMW Sources: nasa.gov; nytimes.com.

Telescope of the Month The Aristarchos Telescope in Greece

Named for the 3rd century BCE Greek astronomer who first proposed that the Earth re-

volved around the Sun, the Aristarchos Telescope is located at the Helmos Observatory in the

Northern Peloponnese, about 80 miles west of Athens, in one of the darkest areas in Europe. Operated

by the National Observatory of Athens (NOA), it was inaugurated in 2007. The Aristarchos is current-

ly focused on the star system in planetary nebula KjPn8. In the constellation Cassiopeia, KjPn8 is unusually shaped with giant

lobes. NOA scientists are trying to determine the distance to KjPn8 and the ages and energy output of its lobes. They discovered

that KjPn8 is about 6,000 light-years away and that its star system ejected matter into space three times: 3,200, 7,200, and 50,000

years ago. Its inner lobe is expanding at 208 miles/s, which suggests it is the result of an Intermediate Luminosity Optical Transi-

ent (ILOT) event. ILOTs happen when a massive star transfers material to a less massive companion, producing high-speed jets.

So, the core of KjPN8 must be a binary system. The Aristarchos is a Ritchey-Chrétien Telescope with a hyperbolic 2.3m primary

mirror and a hyperbolic secondary mirror. This design makes its large 1° field of view free of optical aberrations. But, while

RCTs are compact, like other Cassegrain reflectors (concave primary and convex secondary mirrors), their hyperbolic mirrors are

very expensive to fabricate, making telescopes like the Aristarchos rare. AMW Sources: helmos.astro.noa.gr.; universetoday.com.

NASA/JPL-Caltech

Citizen scientists discovered mys-terious “yellowballs” in Spitzer data.

NASA

The Deep Space Climate Observatory (DSCOVR)

launched on Feb 11.

AAA Around Town Workshop at Adorama

On Feb 15, Michael Rich-

mond of the Rochester Insti-

tute of Technology conducted

a workshop for AAA at

Adorama in Manhattan. He

teaches astronomy and physics

and runs the RIT Observatory.

He discussed urban observing

and described how the human eye is a great instrument for

observing variable stars, even in light-polluted skies. SH

Stan Honda

NASA/JPL-Caltech

Winds from supermassive black holes blast out in all directions.

NOA

4

March 2015

tronomers love the stuff. The presence of CO corresponds

with star-forming regions in galaxies: the molecular cloud in

the constellation Taurus, which is filled with carbon monox-

ide, gave rise to the Pleiades. Very distant dusty galaxies

have CO in their spectrum signatures.

The instrument that is used in the search for CO is the

Zpectrometer, a spectrometer that covers an ultra-wideband

for a broad range of z, or redshift. Redshift tells us how far

away a galaxy is. Our universe is expanding at an accelerat-

ing rate, and the furthest galaxies are receding the fastest. By

the time their light reaches us, the radiation has increased in

wavelength, shifting to the red end of the spectrum. More

distant galaxies have more redshift. Baker uses the

Zpectrometer to look for CO emission lines in the spectra of

high redshift galaxies, with z between 1.9 and 3.4.

The Zpectrometer is attached to the Robert C. Byrd

Green Bank Telescope, which is located within the National

Radio Quiet Zone, an area of about 13,000 square miles near

the borders of Virginia and West Virginia. Cell phone towers

and other radio services are restricted in the Zone, which was

established by the FCC in 1958 to minimize harmful interfer-

ence to the NRAO. Much to their chagrin, the Rutgers stu-

dents who accompany Baker on research trips to the site are

stranded without cell service for days. Unusually, the

Zpectrometer’s electronics are analog, which makes it lighter.

It produces less heat than solid-state electronics.

Describing recent findings, Baker presented data and

images of a galaxy almost completely hidden by dust in visi-

AAA Lecture (cont’d from Page 1) ble light, which was detect-

ed only by CO emission.

Baker also uses the

Zpectrometer to measure

redshifts for galaxies that

appear distorted because of

gravitational lensing by a

foreground object. He

reconstructs what the gal-

axy looks like unlensed,

especially its discrete star-

forming regions, which are

brighter and more active in

the distant galaxies of the

young universe.

Baker also discussed

a new project with the Ata-

cama Large Millimeter

Array (ALMA), located on the dry, 5,000-meter-high

Chajnantor plateau in northern Chile, which will provide in-

sight into star birth in the early universe. It is the largest and

most sensitive instrument in the world at longer millimeter and

submillimeter wavelengths.

During the Q&A following the presentation, an audience

member asked what Baker might report if he returned for an-

other AAA lecture in ten years’ time. He said that he’d hope

to provide a better understanding of early galaxies. Optical

and radio astronomers look at very different things, he ex-

plained, and once all the pieces of the puzzle are assembled,

we might have a better idea of how galaxies evolved.

most of Europa’s oceanic life might be at the bottom instead,

where tidal forces on the rocky interior could create volcan-

ism or hydrothermal vents. We may not find complex life,

like giant octopuses, but we might find microbes down there.

So, don’t hold out for a taste of Europ-ean shrimp cocktail

just yet. But, there are no guarantees for microbes either; we

know tidal flexing affects Europa’s surface, but we can’t be

sure the inner rock seafloor is also tectonically active.

While any discovery of extraterrestrial life would be

significant, finding it so far away would suggest it evolved

independently from life on Earth. If we find Martian life, it is

likely have arisen from material exchanging back and forth

with nearby Earth. It is doubtful that water from Europa

could travel this far into the inner Solar System, escaping

Jupiter’s gravitational pull. Even more unlikely is the possi-

bility that material from Earth could make its way to Europa

unscathed. We can say with confidence that the only Earth

material to reach Europa will be man-made probes.

Studying independently evolved Europ-ean life forms

could be a way to learn more about life outside our Solar Sys-

tem. How do they accomplish growth, reproduction, locomo-

tion, metabolism, etc? If we find they are based on DNA,

then there is a greater likelihood the molecule is fundamental

to life everywhere in the universe. Life unlike us may be very

like us indeed! Sources: researchgate.net; nasa.gov; space.com.

way in. In December

2012, the Hubble Space

Telescope observed

plumes of water vapor

erupting from the south

polar region of Europa.

So, there is at least one

spot where the ice is thin

enough for water to es-

cape, so maybe we can

break in. A probe might

gain access here, with

minimal drilling.

But, once we dive into Europa’s ocean, where will we

find life? If it is anything like Earth, then millions of living

bacteria would be present in every 1.5 gallons of the water.

A probe might meet with success right off the bat and find

microbes on its first plunge. But, it is estimated that Europa’s

ocean has more than twice as much water as Earth. Finding

life may be more difficult in such a vast body of water.

Meanwhile, it is hardly adequate to use Earth oceans as a

guide, when we have explored so little of them – less than 5%

– how much do we really know about marine life?

We do know that living organisms need more than just

water. They need energy and nutrients, which are found in

warmer waters. On Earth, most marine life lives in surface

waters closest to sunlight. Topped by layers of thick ice,

Ocean Exploration on Europa (cont’d from Page 1)

Richard Brounstein’s “What If?” column tests the limits of our

imagination – can the improbable or impossible be reality one day?

Artist’s concept for an underwater probe to explore Europa’s subsurface ocean.

Mark Swinbank (Durham) and Steve Longmore (SAO)

Distant dusty galaxy SMM J2135-0102 is gravitationally lensed by a foreground galaxy cluster. Redshift measurements by the Zpectrometer on the Green Bank

Telescope reconstruct how it looks without lensing (upper left), especially its four active star-forming regions.

5

Still Lovin’ Lovejoy

By Stan Honda

I caught the comet bug after photographing Lovejoy in

early January at the United Astronomy Clubs of New Jersey

(a frosty adventure featured in the February Eyepiece), so I

set out to capture it again. After consulting star charts, I dis-

covered Lovejoy (C2014/Q2) would make a close approach

to the Pleiades star cluster in mid-January, which could make

for a nice composition. All I needed were some dark skies. I

called my friend Rush Dudley in Albuquerque to verify the

dependable New Mexico weather for the next week – reliably

clear skies were forecast – and he suggested heading north to

his brother-in-law Ron’s house in Taos for best viewing.

Using my trusty airline miles, I flew out to meet up with

Rush on Jan 14. We drove up to Taos that afternoon. When

we stepped out into Ron’s backyard after dark, we were

greeted by a lovely view of the Milky Way high overhead and

the brilliant stars of Orion in the south. With a 50mm lens on

a Nikon D800, mounted on an iOptron SkyTracker, I aimed

above the Hunter to shoot the Pleiades and Aldebaran, an

orange-ish star in Taurus. On the camera’s screen, Lovejoy

glowed green with a distinct tail and formed a triangle with

the other two objects. Pretty good results for our first night

out, I thought.

Faint com-

ets are usually

best photo-

graphed with

telescopes or long

telephoto lenses.

In Lovejoy’s

case, I think the

best photos were

taken with rela-

tively moderate

lenses, 50mm to

135mm, on a full-

frame digital SLR

(35mm to 90mm on cameras with APS-C-sized sensors). A

telescope gave excellent close-in views of the comet, but a

wider camera lens allowed me to include other objects,

providing perspective. Having a familiar object in a night sky

photo also adds a common reference point. Lovejoy speeding

past the bright Seven Sisters made for a memorable image.

I hadn’t originally planned to use the 50mm lens – the

choice was serendipitous. I realized the next morning, look-

ing at the star charts again, that I could create a composite

image of Lovejoy’s progression past the Pleiades shooting

over the next five nights with the same lens.

For those five nights, we drove out of Taos to seek even

darker skies, away from the city’s light glow. Winding our

way through the surrounding mountains, we found some

spots well above the 7,000-foot elevation of the city, where

we would experience new levels of cold. Many, many, many

layers of clothing, hand and toe warmers, and frequent breaks

in Rush’s heated van kept us from freezing.

March 2015

Each night,

I shot with the

50mm lens, keep-

ing the composite

in mind, and then

switched to a 70-

200mm zoom, set

at about 100-

135mm, for a

closer image.

Lovejoy’s tail

was quite long

and extended at

least to the edge

of the frame. My

best shot was taken this way, with a 90-second exposure at f4,

at an ISO of 3200. The SkyTracker mount proved to be in-

valuable. It supported the camera/lens combination and

tracked with fairly good precision for the long exposures.

I also took a 300mm f4 lens with me, having gotten

good results with it a week earlier in New Jersey. The lens is

heavier than the 70-200, but the SkyTracker handled the big-

ger load. Jan 15 was an ultra-clear night, and I captured some

great close-ups of Lovejoy with the longer telephoto lens,

using the same exposure as I did with the zoom.

Lovejoy moved rapidly in the sky past the Pleiades, at

least 1° each night. This was my first experience photo-

graphing a comet over time from a dark site, and it was a pro-

ductive trip. Sky & Telescope magazine featured my shot of

the comet and Pleiades on the online gallery’s “Editor’s Pick”

page (http://www.skyandtelescope.com/online-gallery/

lovejoy-passes-the-pleiades). And, Astronomy Picture of the

Day posted some of my images on “Starship Asterisk,”

APOD’s discussion forum (http://asterisk.apod.com/

viewtopic.php?f=29&t=34284&p=239152#p239156).

Back home, I worked on processing the images and put-

ting together the six-frame composite, which took almost as

much time as my trip. Experimenting with various tech-

niques I’ve used for star trails and sun and moon sequences, I

settled on manually layering onto the first night’s photo each

successive image. Aligning the stars while keeping the com-

et correctly oriented proved challenging, but it was worth it.

I now have a beautiful photo to go with fond memories of six

cold January nights observing Lovejoy with friends.

FOCUS ON THE UNIVERSE

Explore more night sky photography at

www.stanhonda.com.

Submit your photography questions to

stanhonda@gmail.com.

Stan Honda is a professional photographer. Formerly with Agence

France-Presse, Stan covered the Space Shuttle program. In his

“Focus on the Universe” column, he shares his night sky images and

explores his passions for astronomy and photography.

Stan Honda

Comet Lovejoy and the Pleiades on Jan 15. Nikon D800, 70-200mm zoom lens at 102mm on iOptron SkyTracker mount, 90 sec., f4, ISO 3200.

Stan Honda

A composite follows Lovejoy’s progress over six nights from Jan 14-19, with the Pleiades (top

center) and orange Aldebaran (left). Nikon D800 with a 50mm lens on iOptron SkyTracker mount,

each exposure 90 sec., f4, ISO 3200.

6

March 2015

misalignment, which is critical for observing. But of course,

chromatic aberration creeps in with a refractor. Color devia-

tion distortion can create a rainbow around the image. This is

acceptable for the amateur astronomer on a budget, because

your first glimpse of the rings of Saturn or the cloud bands of

Jupiter will be crystal clear. Al Nagler has conquered chro-

matic aberration with his TeleVue Optics eyepieces for higher

-end refractors, bringing amateur astronomy to a new level.

Reflectors and refractors were sufficient for amateur

astronomers until 1930, when German

optician Bernhard Schmidt had a new

idea. The Schmidt telescope was cata-

dioptric, combining the best of re-

flectors and refractors to offer aberra-

tion-free images with a compact,

sealed tube design. It was based on

Laurent Cassegrain’s 1672 reflector.

In 1941, Dmitri Maksutov patented his

version, now known as the Matsukov-

Cassegrain telescope. However, the shorter tube length de-

sign sacrifices some image brightness in exchange for this

versatile and extremely portable telescope.

If you attended the AAA Astro Answers event at

AMNH in November, you were treated to a program honor-

ing the grandfather of sidewalk astronomy, John Dobson,

who passed away in 2014. His Dobsonian telescope modified

the Newtonian reflector (invented by Newton in 1668), using

a parabolic primary mirror and secondary flat mirror to focus

light. Dobson increased the size of the primary mirror to

gather the maximum amount of light possible, so distant ob-

jects would become clearer. The

Dobsonian looks more like a can-

on than a telescope, and it rests

squarely on a base on the ground,

unlike most tripod-mounted tele-

scopes. Dobsonians can get size-

able and expensive, depending

upon the manufacturer and op-

tics, so you might find a used one

to fit your budget.

So, where can you go to find your first telescope?

Visit Mike Peoples at Adorama in Manhattan! As AAA’s

strategic partner, he often speaks at StarFest events and has

recommendations and discount telescopes for AAA members.

Email him with your questions at michaelp@adorama.com.

Purchasing new equipment is exciting, but remember

that the best telescope you buy is the one you actually use.

Take it out as often as you can on as many nights as possible,

even just to practice setting it up. The scope not gathering

dust in the closet is the scope that fits you just right!

Sources: astronomynotes.com; amazing-spacestudies.stsci.com; space.com;

universetoday.com; space.about.com; astronomics.com.

Hello again, amateur astronomers of the AAA! With the

second article of this series, it’s time to take the next step on

your journey to the stars. In January, we took a look at a set

of 7x50 binoculars as a way to begin observing the Moon and

several planets. With this basic set of eyes, you can learn to

familiarize yourself with the night sky and get a glimpse of

distant objects, like the Andromeda Galaxy (M31), which is

2.2 million light-years, or thirteen thousand quadrillion miles,

away. Although just a fuzzy ball of light, it can be found

between the constellations Pegasus and Cassiopeia.

Now, let’s turn our focus to starter telescopes. If binocu-

lars were your launch pad, a telescope will be your first or-

bital flight. Just as NASA takes space exploration one step at

a time, you should step up your equipment in phases, giving

you time to learn more about the optics behind observing.

This way you can stretch your night sky knowledge before

leaving orbit to explore deep space targets. There’s so much

to see (and perhaps photograph, someday), and a starter scope

can up your astronomy game, without breaking the bank.

Entry level telescopes come in several flavors, but they

all gather light and deliver it to an eyepiece. Here is a review

of the merits of each, in the context of first-time observing.

Reflectors use one or a se-

ries of curved (concave) mirrors to

bring an image to the eyepiece.

This parabolic mirror takes the

distant light of a star, which arrives

to Earth as a series of parallel rays,

and combines it into a single im-

age. Other telescopes are subject to

chromatic aberration, where the

colors of the spectrum are not

properly aligned during capture, but reflectors focuses across

all wavelengths of light, so no problems there. But, reflectors

to have a negative side. Their optics can fall out of alignment,

and the tube, which is open to the air, requires frequent

maintenance to keep the inside clean and free of dust. If

you’re looking for less fuss for your first telescope, then this

may not be your best option.

Refractors are my personal favor ite. Instead of us-

ing a mirror to gather light, a refractor uses a glass lens. The

first telescopes built were refractors, so there’s a lot of history

here. Galileo built a small, two-lens refractor to make his

celestial discoveries. His legacy is felt in the continued de-

velopment of this popular design. The largest refractor ever

built is at the Yerkes Observatory in Williams Bay, Wiscon-

sin. In 1897, George Ellery Hale,

who went on to support the work of

Edwin Hubble, persuaded a wealthy

Chicago businessman to fund the 40

-inch refractor, which still operates

today. The sealed tube of a refrac-

tor protects it from the elements,

and images remain crisp and clear.

The rugged design also prevents

The Amateur Astronomers’ Series – Part 2: Optical Options for Telescopes By Evan Schneider

Sidewalk astronomer John Dobson (right) invented his

popular telescope in the 1960s.

Reflector telescope

Refractor telescope

Catadioptric telescope

Evan Schneider’s series seeks to encourage AAA members to find a

telescope and fall in love with observational astronomy.

7

March 2015

Probing the Universe Dawn to Arrive at Dwarf Planet Ceres this Month

On Mar 6,

NASA’s spacecraft

Dawn will enter a five-

month orbit around

dwarf planet Ceres,

the second target of its

two-part mission to visit

large, intact protoplan-

ets and learn about the

early Solar System. In 2011 and 2012, it explored the giant

asteroid Vesta. Both bodies formed early, in the first 10 mil-

lion years of the Solar System, and reside in the Asteroid

Belt between Mars and Jupiter, but they evolved differently.

Vesta was discovered to be a differentiated, terrestrial world,

like inner solar system bodies. Dawn found evidence of hy-

drated materials enriched and depleted across Vesta’s dry,

basaltic surface. Larger, less dense Ceres, which has water

vapor in its thin atmosphere, is believed to be icy, like bodies

of the outer Solar System. Just a little further from the Sun,

Ceres managed to form wet and stay cool, while Vesta’s ac-

creting material melted from solar heat. Closing in on Ceres,

Dawn’s sharp images of the dwarf planet reveal craters and

curious bright spots. “We expected to be surprised; we did

not expect to be this puzzled,” said Chris Russell, Dawn’s

principal investigator. He and his team will get a closer look

at these features very soon. AMW Source: nasa.gov.

Catching up with Comet Catcher Rosetta

By Richard Brounstein

“Let's talk about comets!” began Dr. Joel Parker, a

member of the U.S. science team working with the European

Space Agency’s Rosetta spacecraft. On a freezing night in

February, space lovers traversed an icy city to hear him speak

at AMNH about icy Comet 67P/Churyumov–Gerasimenko

and Rosetta’s historic mission to that Solar System object.

Centuries ago, humans knew almost nothing about com-

ets. Ancient observers thought these ethereal objects showed

up suddenly in the sky before disappearing mysteriously.

Were they sent by the gods as a portent of doom, to warn of

an impending plague or the death of a monarch? Unlike stars

and planets, their movements seemed totally unpredictable.

Now, we know their motions and orbits are, in fact, predicta-

ble. We also know where they come from. Thanks to modern

astronomy and advanced spacecraft, like the Deep Impact

probe, which purposely collided with Tempel 1 in 2005, we

even know what they’re made of. These dirty snowballs are

actually icy dirtballs. They are about as dirty a place as you

can find in the Solar System, and that is where ESA has sent

its expensive and pristine space probe.

Rosetta has made the first true rendezvous with a comet,

and its companion, Philae, made the first comet landing, set-

ting down (after a few bounces) in November. Comet 67P

Celestial Selection of the Month Thor’s Helmet

About 12,000-22,000 light-years away in the constel-

lation Canis Major is a bright, hot, giant star about to go

supernova. A Wolf-Rayet class star, WR7, is 16 times more

massive than the Sun, and it is losing that mass quickly, bil-

lions of times faster than the Sun, through intensely strong

stellar winds. Wolf-Rayet stars are rare and distant. They

are a brief stage in the end-life of the most massive stars,

occurring once they’ve lost most of their outer layers. Such

exceptionally massive stars are rare themselves, because they

form less often and have short lifespans. Wolf-Rayets con-

tinuously eject gas into space, producing an expanding enve-

lope of nebulous gas. Surrounding WR7 is an emission neb-

ula known as Thor’s Helmet (NGC 2359). Most of its struc-

ture is a bubble formed by stellar wind, but interactions with

a nearby molecular cloud are likely responsible for the

curved, bow shock shape that

forms the horns on the Norse

god’s headgear. Scientists

estimate NGC 2359’s age be-

tween 78,000 and 236,000

years, but they are not sure if

it was created by its central

star as Wolf-Rayet WR7 or as

its predecessor, a massive red

supergiant. AMW

Sources: wiki.com; apod.nasa.gov.

AMNH FRONTIERS LECTURE

was full of sur-

prises. The

Hubble Space

Telescope had

provided only a

fuzzy image of

the peanut– or

duck-shaped

object. Getting up close, Rosetta took higher resolution imag-

es and mapped 70% of the comet’s surface, revealing moun-

tains, sharp cliffs, surface cracks, and boulders.

Comets date back to the early Solar System, and they

have remained mostly unchanged for 4.6 billion years. There

are two different types: Jupiter-family comets are bound

within the orbit of Jupiter but formed in the Kuiper Belt, be-

yond the orbit of Neptune; while long-period comets come

from the Oort Cloud, a vast area of space far at the edge of

our Solar System. Every once in a while, one of these makes

its way into the inner solar system. Good thing they come to

us, or else we would never get a chance to study them.

Scientists believe that these far-off comets may be re-

sponsible for bringing water to the planets of the inner Solar

System. In every glass of water, you may be drinking a small

amount of comet water. But, in order to determine if Earth’s

water came from a comet, we need to know if it has the same

flavor. Scientists measure the water’s ratio of deuterium (a

hydrogen isotope) to regular hydrogen. The D/H ratio of

AMNH Frontiers Lecture (cont’d on page 8)

ESA ESA

Comet 67P/C-G imaged by the OSIRIS camera on Rosetta in July and August 2014 from 3,400 mi

(right) and 177 mi (left) away, respectively.

Bob and Janice Fera

A blue-green color indicates oxygen atoms in the gas from a

strong emission of Thor’s Helmet.

NASA

Dawn took its sharpest images of dwarf planet Ceres from 52,000 mi away in Feb.

8

March 2015

Hello AAA Members!

Most of you have renewed your AAA Membership for 2015, and

we thank you! If you haven’t done so yet, renew by mail, or online

through the portal at www.adminaaa.org. You will need your member

ID and password for login. Please renew as soon as possible. We hope

you will also consider making a contribution to AAA with your renewal.

AAA has a new website! Thanks to all our members who volun-

teered their time, especially Susan Andreoli and Stan Honda. Kudos on

a job well done! It looks great on mobile devices too. PHOTO CALL:

AAA would like to post your pics on the new website. Please send

photos via email to president@aaa.org, and include a brief caption.

SAVE THE DATE for the annual AAA Spring Starfest at Wood-

lawn Cemetery on May 2. Keep an eye out for more details to come.

Lastly, don’t miss the next lecture in the AAA series at AMNH

when Neelima Sehgal discusses dark matter, neutrinos, and the inflation-

ary theory of the universe on Friday, March 6. Check out the entire

lecture schedule at www.aaa.org/lectures.

Marcelo Cabrera

AAA President

Message from the AAA President

The Amateur Astronomers’ Association of New York Info, Events, and Observing: president@aaa.org or 212-535-2922

Membership: members@aaa.org Eyepiece: editor@aaa.org

Visit us online at www.aaa.org.

Eyepiece Staff March Issue

Editor in Chief: Amy M. Wagner Copy Editor: Richard Brounstein

Contributing Writers: Richard Brounstein,

Tony Faddoul, Stan Honda, Evan B. Schneider, and Amy Wagner

Administrative Support: Joe Delfausse

Printing made possible by McVicker & Higginbotham

67P’s water is 3 times higher than that in Earth’s oceans, so

it’s definitely not a match. It is also higher than the D/H ratio

on fellow Jupiter-family comet Hartley 2 – the only comet

measured that does match – and even higher than those of

long-period Oort cloud comets.

With all this water and ice, one would think that comets

would be bright reflective objects. Not so. Comet 67P is as

dark as coal. It reflects only about 4-6% of the light it re-

ceives. Compare that with Earth, which reflects 30-35% of

light. The bright photos of 67P taken by Rosetta required

long exposure times. You might also think that rocky 67P

would be a dense object. Not so. It would float on an ocean

like an enormous rocky iceberg.

The most extraordinary achievement so far for the Ro-

setta mission was landing the Philae probe. Its gravity is so

low (1/60,000 of Earth) that a tennis ball dropped from one

meter above would take 2 full minutes to hit the ground. 100

kg Philae weighs about the same as a piece of paper on 67P.

The lander had harpoons to grab the surface and hold on after

contact. Philae’s landing was also

completely unpowered. Rosetta

released Philae on a certain trajec-

tory – no rocket thrusters were

engaged to slow the lander or ad-

just its course. It relied solely on

Newton’s laws of gravity to land.

Like a slow marathon runner, it

travelled 22 km in 7 hours.

Philae landed right on target. Unfortunately, the har-

poons to secure it onto 67P’s surface failed. It bounced four

times before finally getting wedged between some shady

rocks. Although Philae ran out of power, blocked from sun-

light, it turned out to be an opportunity in disguise. Philae’s

instruments now have dust samples from four different sites.

Rosetta learned that 67P has surprisingly little ice on its

surface. Its ice is buried up to several meters under rock.

The temperature differences in the rocks are enormous. Are-

as only inches apart can have a temperature difference of 100

degrees Celsius.

In early February, Comet 67P was far from the Sun, so

there was very little outgassing. About two cups of water a

second were released. In a few months, as it comes closer to

the Sun, outgassing will reach 80 gallons of water a second.

This will be exciting to watch, and if sunlight can reach Phi-

lae to power it up and communicate with Earth, we will get a

front row seat to the action, watching a comet come to life

from the surface. Here’s hoping!

AMNH Frontiers Lecture (cont’d from page 7)

SUN, Mar 1 @ 6:00 pm

Entertaining Science Series at Cornelia Street Cafe, P “Pluto and the Arrival of New Horizons,” a lecture by AAA’s Jason

Kendall. Seating is limited. Tickets are only available at the door.

FRI, Mar 6

@ 6:15 pm AAA Lecture at AMNH, M Next: April 17 “Understanding Dark Matter, Neutrinos, and Inflation with CMB Obser-

vations” with Neelima Sehgal in the Kaufmann Theater. (Enter 77th St)

@ 6-9 pm Observing at Sunnyside Gardens Park - Queens, PTC

This private park will be open to the public for a special observing

event for all ages, with fun activities, hot drinks, and baked goods. (Alternate date for inclement weather: SAT, Mar 7)

MON, Mar 9 @ 7:30 pm

AMNH Frontiers Lecture at the Hayden Planetarium, P “Supernova Forensics: A Stellar Investigation from Cradle to Grave and

Beyond” with Alicia Soderberg. Review new results from Harvard’s

Supernova Forensics team and find out how scientists study star explo-

sions that happen far away and long ago. (Enter 81st St)

SAT, Mar 21 @ 12 - 5 pm

NASA Sun/Earth Day at the Cullman Hall of the Universe, P Explore the special relationship between the Sun and Earth. Talk with

scientists, look through telescopes, and get hands-on at AMNH.

FRI, Mar 27 @ 8 pm

Columbia University Stargazing & Lecture at Pupin Hall, P “How to Build a Galaxy” with Munier Salem. (Observing 8:30pm , C)

TUES, Mar 31 @ 6:30 pm

AMNH Astronomy Live at the Hayden Planetarium, P “Our Cosmic Address” with Br ian Abbot and AAA’s Chr istina

Pease. Hone in on Earth’s position in the Solar System, Milky Way

galaxy, and the observable universe. (Enter 81st St)

C: Cancelled if cloudy; M: Members only; P: Public event; T: Bring telescopes, binoculars.

For location & cancellation information visit www.aaa.org/calendar.

AAA Events on the Horizon

ESA

Rosetta’s Philae lander.