The Celestial Observer

The Celestial Observer                                                                                              co_logo

Fall 2016

Science at the cutting edge . . . is not about self-evident facts. It is about mystery and
not knowing. It is about taking huge risks. It is about wasting time, getting burned,
and failing. It is like trying to crack a monstrous safe that has a complicated, secret lock
designed by God.

Richard Preston, First Light: The Search for the Edge of the Universe

President’s Letter

Welcome to the Fall 2016 issue of the Celestial Observer! Many thanks are due
to NSAAC VP and editor Dick Luecke, and thanks go out to our contributors as
well. Inside you’ll find some great advice from Bryan Stone on buying
equipment, Glenn Chaple’s challenge object, and more.

At Boy Scout Park there are now more leaves on the ground than in the trees,
so it’s time to say goodbye to Hercules and the summer objects, and hello to
M1 and those Auriga open clusters, M42 and its surrounding nebulae, Gemini’s
Peanut (look it up) and the Eskimo, and all those great cold-weather objects.
Fall and winter present us with a tradeoff: we’ll need winter coats, gloves and
boots, but no more trying to peer through a haze of bug spray and miles of
water vapor either. Transparency improves and light domes shrink. I always
look forward to cool, dry weather observing.

For our Fall meetings, we’re planning on finishing out the year in style — we’ve
got a really fun movie night scheduled for November 4 (the title is a closely-held
secret, but there will be popcorn), and with any luck we’ll be able to do some
observing afterwards. We’re also planning a holiday bash for December 2 with
a half-dozen quick, back to back presentations by members on a variety of
interesting topics, and of course a table full of holiday goodies! We hope you’ll
join us there. We’re going to have a terrific time.

I am heartened by the attendance at our recent observing sessions, and the
increasing participation by new members and old friends in our monthly
meetings. I think we’re transitioning nicely to a more outward-looking
organization, which I promise is a good thing. When you see John Hobbs don’t
neglect to thank him for the great publicity he’s been getting us, and be sure to
let Brewster Lamacchia and Dennis Gudzevich know you appreciate their
tireless outreach efforts. As we finish out 2016 I’m really looking forward to
more good fortunes for NSAAC – by which I mean more fun at meetings and
more time spent observing.

–Michael Deneen

Gifts for Aspiring Astronomers

We are approaching the holiday gift-giving season. There is a good chance that
someone close to you has an interest in stargazing. If that is the case, read on.
This article aims to help astronomy newcomers and well-meaning gift-givers to
avoid the mistakes that others (ourselves included) have made. We want
people to buy good, usable telescopes because, with care, good equipment will
provide a lifetime of service and enjoyment. Conversely, bad telescopes
frustrate users and quickly sap their initial enthusiasm for astronomy. Bad
scopes are difficult to use and quickly end up in a corner or closet gathering
dust.

Before we begin our discussion of telescopes, however, consider that one of the
best gifts for anyone interested in the night sky is a membership in an active,
local astronomy club. Membership provides an opportunity to try out a variety
of equipment and to get lots of valuable, personalized advice before a dime is
spent. Books and online sources can provide the basic know-how of astronomy,
but much more can be learned at club meetings, observing sessions, and star
parties.

Our club goes a step further: it conducts “scope clinics” through which
experienced members assist newcomers and people in the community who are
having difficulty with telescopes they either purchased or received as gifts. And
we’ve seen all types–the good, the not-so-good, and the downright ugly.

  Which is the Right Scope?

Okay, so what telescope should you buy for yourself or for that person on your
shopping list? Our club members differ on what constitutes the ideal telescope,
but all agree on two essential points. First, the best telescope is the one that
you will use the most often. A giant telescope is great, but if it takes too long to
transport and set up in the field, it won’t show you as much as a high quality but
smaller “grab and go” instrument. Second, we all agree on which telescopes to
avoid:
• Any telescope sold in a department store, toy store, nature store, etc.
Few of these are serious, quality instruments. Good equipment can
sometimes be found on eBay or Craig’s List, but be careful. See the
scope in person first, if possible, and/or seek the advice of an
experienced amateur astronomer.
• Any telescope advertised by magnification (i.e., power, or “X”). “500
power!” These are scams. Any telescope can be pushed to any
magnification, but most super-high-powers are unusable and show
nothing.
• Any telescope that uses substandard 0.965-inch eyepieces. You want
one that uses standard 1.25-inch eyepieces. Scopes that also take 2-
inches are even better still.

What About “Go-To” Scopes?

Computerized, “go-to” and tracking telescopes are very popular, but don’t buy
one unless you’re willing to spend at least $1,500. The problem with
inexpensive go-to scopes is that too much of the price goes into the computer
and drives, and not enough into quality optics and a stable mount. This doesn’t
apply to “push-to” Dobsonian reflectors whose simple electronics help you
point to the desired object, leaving the user to do the rest. We like these
scopes; some can be purchased for less than $500.

What’s Your Budget?

My opinion (though some disagree) is that if you have less than $200 to spend,
you shouldn’t buy a telescope at all. The recipient will be much better off with a
good quality pair of 7×50 binoculars, a subscription to one or both of the leading
astronomy magazines (“Sky & Telescope,” “Astronomy”), and the superb book,
Turn Left at Orion. These are great for beginners and very useful for advanced
stargazers as well. Then start saving for a real telescope.

If you have $200 to spend, a great choice is the “One Sky” offered through
Astronomers Without Border. This compact instrument was reviewed favorably
by Sky & Telescope Magazine and found to be one of the top beginner’s
telescopes of all time. The One Sky has a 5-inch mirror, two good eyepieces, a
red dot finder to help with aiming, and a simple, steady tabletop mount. If
there’s more money in your budget (e.g., $500-$800), a Dobsonian scope, either
manual or push-to, with an 8- or 10-inch mirror can be a lifetime scope. If your
spending limit is even higher, come to a club meeting for personalized advice, or
join one or more of the online forums on Cloudynights.com.

Clear skies and happy holidays to all!
Bryan Stone
Past President and At-Large Board Member

Sky Object of the Month

The ever-resourceful Glenn Chaple has provided our galaxy hunters with yet
another interesting object: NGC 7479 (Caldwell 44), barred spiral located just
beyond the southwest corner star of the Square of Pegasus. Save this
magnitude 11 object for a very dark night, otherwise you might fail to locate it.
Go to the club website for the details and a handy star chart.

And while you’re at the website, check out Glenn’s September pick,
NGC 7009 (Caldwell 55), the blue-green 8.0 magnitude “Saturn” planetary
nebula located in Aquarius. This striking object is low in the southwestern sky in
early-to-mid November and sinking lower with each passing week, so get on it
soon.

NGC 7479 (Caldwell 44)

image001

Photo: Fort Lewis (CO) College Observatory

NGC 7009 (Caldwell 55)

image002

Photo: Mario Motta

Is Proxima Centauri’s ‘Earth-like’ planet actually like Earth at all?

Ethan Siegel

This article is provided byNASA Space Place. With articles, activities,
crafts, games, and lesson plans, NASA

Space Place encourages everyone to get excited about science and technology. Visit
spaceplace.nasa.gov to explore space and Earth science!

Just 25 years ago, scientists didn’t know if any stars—other than our own sun,
of course—had planets orbiting around them. Yet they knew with certainty that
gravity from massive planets caused the sun to move around our solar system’s
center of mass. Therefore, they reasoned that other stars would have periodic
changes to their motions if they, too, had planets.

This change in motion first led to the detection of planets around pulsars in
1991, thanks to the change in pulsar timing it caused. Then, finally, in 1995 the
first exoplanet around a normal star, 51 Pegasi b, was discovered via the “stellar
wobble” of its parent star. Since that time, over 3,000 exoplanets have been
confirmed, most of which were first discovered by NASA’s Kepler mission using
the transit method. These transits only work if a solar system is fortuitously
aligned to our perspective; nevertheless, we now know that planets—even
rocky planets at the right distance for liquid water on their surface—are quite
common in the Milky Way.

On August 24, 2016, scientists announced that the stellar wobble of Proxima
Centauri, the closest star to our sun, indicated the existence of an exoplanet. At
just 4.24 light years away, this planet orbits its red dwarf star in just 11 days,
with a lower limit to its mass of just 1.3 Earths. If verified, this would bring the
number of Earth-like planets found in their star’s habitable zones up to 22, with
‘Proxima b’ being the closest one. Just based on what we’ve seen so far, if this
planet is real and has 130 percent the mass of Earth, we can already infer the
following:
• It receives 70 percent of the sunlight incident on Earth, giving it the right
temperature for liquid water on its surface, assuming an Earth-like
atmosphere.
• It should have a radius approximately 10 percent larger than our own
planet’s, assuming it is made of similar elements.
• It is plausible that the planet would be tidally locked to its star, implying
a permanent ‘light side’ and a permanent ‘dark side’.
• And if so, then seasons on this world are determined by the orbit’s
ellipticity, not by axial tilt.

Yet the unknowns are tremendous. Proxima Centauri emits considerably less
ultraviolet light than a star like the sun; can life begin without that? Solar flares
and winds are much greater around this world; have they stripped away the
atmosphere entirely? Is the far side permanently frozen, or do winds allow
possible life there? Is the near side baked and barren, leaving only the ‘ring’ at
the edge potentially habitable?
Proxima b is a vastly different world from Earth, and could range anywhere
from actually inhabited to completely unsuitable for any form of life. As 30mclass
telescopes and the next generation of space observatories come online,
we just may find out!

Looking to teach kids about exoplanet discovery? NASA Space Place explains stellar wobble and how this phenomenon can help scientists find exoplanets:
http://spaceplace.nasa.gov/barycenter/en/

co-2016-image-1

An artist’s conception of the exoplanet Kepler-452b (R), a possible candidate for Earth 2.0, as compared with Earth (L). Image credit: NASA/Ames/JPL-Caltech/T. Pyle.

Upcoming NSAAC Events
Club monthly meetings: First Friday of the month, 7:30 PM at the Boxford
Community Center, 2nd floor.

If the sky is clear and spirits are willing, we’ll try to wrap up these meeting and presentations expeditiously and get out to Boy Scout Park for some observing.

Club observing sessions:
If the weather co-operates, we may have a combined public/NSAAC event at
Battis Farm in Amesbury on November 1 or 3. Battis Farm is located off of South
Hampton Road. https://goo.gl/maps/2PYl4. The setup location is over the ridge:
http://w3w.co/yards.fish.lobby

Official observing will be from 7PM to 8:30PM; unofficially we can stay until the
cows come home.

Watch for announcements through the email listserv.

Club sponsored public star parties: None scheduled until Spring.

Collins Observatory will be open on Monday nights at dusk when Salem State is
open and the sky is clear. Check nsaac.org (under “Observing”) for details. And
remember that SSU has many closed days during the holiday season.

Mendel Observatory Merrimack College’s observatory is open every
Wednesday from dusk until 10 p.m. when the sky is clear. Check
http://nsaac.org/about-the-club/merrimack-college-mendel-observatory/
before driving out.

Article Proposals Welcomed!
The Celestial Observer welcomes proposals for original articles of 500-900
words. Do you have something you’d like to share with NSAAC members:
recommended telescopic targets for the upcoming season? an equipment or
book review? your experience with something that others might try, such as
renting time on a large on-line telescope? If you do, send a brief proposal to
vp@nsaac.org.

–Dick Luecke, editor

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