Sacramento Valley Astronomical Society

Forrest Lockhart

In the first Meridian article last month, I described the observing plan and the scopes to be used for ferreting out interesting objects appearing at or near the meridian that month. There was only one E-mail response to my request for celestial targets for April, but it turned out to be a good choice. The member asked what, if anything, I could see of the open star cluster, Messier 44 under suburban skies. The question brought back memories of the old Messier Group, for I had not observed the cluster since then.

Since I was to be working at the Cameron Park Community Observatory in a few days, and I could make use of the 4” refractor there instead of using my own, I decided to take another look at M44.

Messier 44, commonly known as the Beehive Cluster, was born 400 million years ago from the collapse of a large cloud of gas and dust about 500 light years away. The result was the creation of a cluster of approximately 200 stars spanning about 11 light years. The calculated combined magnitude is 3.1, which should make it stand out well against suburban sky glow, but that isn’t necessarily so. According to astronomy author Stephan James O’Meara, the brightness of the individual cluster stars range from 6^th to 14^th magnitude. So what was my experience with M44?

On a clear observing night with a thin crescent Moon and a limiting visual magnitude of about 4.5, we hosted a group of college students on a field trip to the observatory. I took them outside and, using a laser pointer, gave them a general area to observe with the unaided eye. While a few knew what they were looking for, most did not. They were only told to look at the area and report what, if anything, they could make out. Since the host constellation of Cancer is so faint, M44 is the brightest object in the area. Of 16 students, 15 reported a misty, cloudlike ellipse about the size of a full moon.

Back in the observatory, I directed the 14” SCT scope with the attached 4” refractor to M44. Magnification on the 14” was 125x, while the refractor was set to 27x. Due to the angular diameter of M44, the view through the 14” scope was truly disappointing. Too little of the cluster could be observed in the limited field of view. However, in the 4” scope with its FoV of nearly 3 degrees, the view was scintillating, with at least 70 stars glinting like diamonds on a dark background.  The students were impressed with the view, and I felt that I had re-discovered an old favorite.

Upon my return home that evening, I grabbed my 80 mm Stellarvue, placed it across a convenient tree limb in the front yard and took another squint at M44. While I do not recommend a tree limb as a substitute for a sturdy mount, I was again quite mesmerized by the impact of a low-power view of M44 at the meridian.

If you have a favorite object that will be in the vicinity of the meridian in May, please E-mail me at <forrest.lockhart@sbcglobal.net> with your observations. I’ll try to give it a good look and report back in the May SVAS Observer.

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“Urban Astronomy”: A Great Night for DSOs

Margo Schulter

["Urban Astronomy" is my project to encourage
the observing of Deep Sky Objects (DSO's)
in urban or suburban settings, with a due
acknowledgment that these objects will, of
course, be yet more impressive in darker
skies. Questions or comments by e-mail are
warmly invited.]

Saturday night was a great opportunity for some
DSO watching at Quadrivium Urban Observatory (QUO),
otherwise known as my bedroom, just north of CSUS.

As twilight deepened, Canis Major was a big
attraction, with M41 announcing a delightfully
clear night. I could say, “Good, the less than
ideal viewing earlier this year reflected mist
rather than a sudden increase in light pollution!”

The tour — with my 15×70 binoculars, handheld
with a bit of bracing for the most part, while
reclining — moved to Cr 140, often known to
dark-sky observers who see it with the naked
eye as “The Tuft in the Tail” of Canis Major,
but appearing in binoculars as what I call
Ursa Australis, or “The Southern Bear,” in
my version an asterism including stars in both
Canis Major and neighboring Puppis.

Other open clusters among my urban favorites
are Cr 132 (“Mulberry Cluster”), Cr 135
(Pi Puppis Cluster), and NGC 2451. The latter
two were evidently described by Giovanni
Battista Hodierna in 1654, whose catalogue
of nebulae, like Messier’s, includes some fine
objects for astronomers at all levels of
experience at a latitude like Southern Sicily’s
or Sacramento’s.

One notable event occurred around 1920, when
a satellite (moving mostly north to south)
passed just east of M41. I followed it for
a bit, and then lost the track when I looked
at a red LED clock to check the time. I guess
that I have a strong “hunter’s instinct” to
chase tofu and satellites.

As the evening continued, I was pleased to
locate one of my favorite objects: M93, a good
example of a “faint fuzzy” still clearly visible
with 15×70 binoculars in an urban setting.

At some point, I also did a bit of careful
positioning to get a view of the Sword of Orion:
NGC 1981 and 1977, M42, and NGC 1980. This was
an especially appropriate sight, since this
month marks the 400th anniversary of Galileo’s
_Sidereus Nuncius_, the “Starry Messenger”
(or, perhaps, the “Celestial News”). While it
was his planetary observations which became
the main focus of immediate attention, his
deep sky observations (with M42 and M45, the
Pleiades, as examples of how many more stars
became visible with his primitive telescope)
would inspire Hodierna to make his much more
extensive catalogue and atlas maps.

Gamma Velorum in Vela, “The Sails,” also seemed
in evidence: at a declination of around
-47 degrees, this star marked about the southern
limit of Hodierna’s maps, as was a test of my
ability to see around, or through, some lofty
trees that have apparently been getting a bit
taller in my neighborhood.

A final treat of the evening was the “Alien”
asterism including the bright and reddish
star Lambda Velorum: this asterism looks a
bit like a sidewise view of the head of a
friendly extraterrestrial with what might
be antennae (with east-west as “up-down”).
My warm thanks to Andrie van der Linde, an
amateur astronomer in South Africa whose
newsletter called this charming asterism
to my attention!

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SUPERNOVAE – SOME OF THE BRIGHTEST STARS AROUND

As any amateur astronomer worth their salt knows: Supernovae are enormous explosions that destroy an entire star.  Because of this explosion, supernovae are much brighter than their surrounding star companions.  Their luminosity makes them conspicuous, and the energy they emit makes them interesting to scientists.  But supernovae are quite rare, with an estimated rate of only one occurring every 25 to 100 years for a galaxy the size of our Milky Way.  Yet this estimated rate may be overly generous since we haven’t witnessed a supernova in our home galaxy since Kepler’s Star in 1604.  That’s over 400 years ago, before the telescope was even invented.

Well, for those members of SVAS who felt that they were over due for a supernova, their observing wishes were answered at the SVAS Annual Membership Meeting.  There, the supernovae of SVAS were awarded the highest honors and acknowledgment of appreciation that the Society can bestow on its members.  Lynda Hall acted as the master of ceremony when three individuals were awarded the SVAS Star Award.  The Star Award winners for 2009 are Ray Brown, George Foxworth, and Tom Silver.  They received the award in recognition of their tenacious participation in community events over the last few years.  Margaret Minnick was recognized with a Service Award for her contribution as Community Star Party Coordinator.

This ceremony was followed by the awarding of the Natalie Leonard Award.  Named after a lifelong member who contributed greatly to the Society throughout her many years of service, this award is SVAS’s highest honor.  It is awarded in recognition of similar long-term service to the SVAS.  For 2009, the Board was proud to present this award to a collective of individuals that were the gravity that bound all SVAS members together — the former newsletter crew. 

As you know by now, SVAS has gone electronic and is no longer publishing a hardcopy of the Observer Newsletter.  During the last nine years, Dave Buchla, Chris Hulbe, Claudia Hulbe, and David Larzelere worked together to compile, edit, and distribute one of the most informative and aesthetically appealing astronomy club newsletters around.  They consistently produced a product that made all of SVAS proud.  With the advent of the e-Observer, this crew has retired from the newsletter production.  So it was only fitting that the SVAS recognize their contributions with an overdue expression of sincere gratitude in the form of the Natalie Leonard Award. 

Although retired from newsletters, I’m sure they, along with the Star Award winners, will continue to shine bright in the future.  But as with all supernovae, there is the risk of the brilliant flash turning into a black hole.  So if you would like to brighten your star and keep the galaxy of SVAS ablaze with energy, then step forward and volunteer to help out at a community or member’s event.  Just contact any Board member.  We are just starting a new observing season and there are plenty of opportunities to let your star shine. 

Ross Gorman,

President

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Those who missed the Annual Meeting on Friday, March 19, missed some good cake. The evening began with a moment of silence for Chris Hulbe while a slideshow of pictures of Chris showed him at various times in his amazing life. Many who have known Chris over the years relayed memories of wild “field trips” to the most unlikely places with the most pleasant results, his magnanimous heart, his astounding knowledge of Geology, Physics and Astronomy, and his tremendous positive influence on everyone around him (with several references to “Kris Kringle”  interjected throughout).  Claudia brought enlarged photos of several big players in Northern California astronomy history, including pictures with Art and Natalie Leonard.

   It was nice to see a picture of the woman for whom the SVAS’ highest award is named. The Natalie Leonard Award is granted only on occasion to recognize extraordinary service to the SVAS. The Award was given that night to our former newsletter crew: Chris Hulbe, Claudia Hulbe, Dave Buchla and David Larzelere.

   Also recognized with a Star Award for long-time service “above and beyond” were George Foxworth and Ray Brown, two long-time and unbelievably reliable outreach volunteers as well as all-around good-guy Tom Silver for his contributions to outreach, inreach, the membership committee and the board.

   Last, but definitely not least, Margaret Minnick received a Service Award for her time as our former Community Star Party Coordinator. A brave thing, indeed, as Margaret had never actually attended a star party and wasn’t sure what it entailed when she agreed to take it on- which she did and quite well.

   Our thanks go out to all of them, we are grateful for what you’ve given!

   While we awaited word from the teller committee, the membership enjoyed a 65^th Anniversary birthday cake for the SVAS provided by candidates Andrew Gallagher and Ross Gorman- it wasn’t chocolate, but it was still good. Thanks Andrew & Ross! After our treasurer, Kirk Alexander gave a report on our financial status (not great, not grim- we’re just breaking even), Liam entertained the crowd with talk of comets, the Oort Cloud, red dwarfs and the impending destruction of the solar system until the teller committee appeared just before 10 pm with the results of the election.

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Dr. Kimberly Ennico, NASA Ames Research Center, will be the speaker for the February SVAS General Meeting. The topic is: “The LCROSS Mission.”

Friday, February 19, 2010 at 8:00 PM, at Sacramento City College, Mohr Hall Room 3, 3835 Freeport Boulevard, Sacramento, CA.

Please click here for location information and maps.

Title:
“Hitch-hiking to the Moon, LCROSS, the lunar impactor that made a big splash on our understanding of the Moon”

Abstract:
The LCROSS (Lunar Crater Observation and Sensing Satellite) mission’s objective is to sample and analyze regolith from a permanently shadowed region (PSR) on the Moon, providing the first in-situ study of a PSR. LCROSS has four specific science goals: (1) Confirm the presence or absence of water ice in a PSR on the Moon; (2) Identify the form/state of hydrogen observed at the lunar poles; (3) Quantify, if present, the amount of water in the lunar regolith, with respect to hydrogen concentrations; and (4) Characterize the lunar regolith within a permanently shadowed crater on the Moon.

LCROSS launched successfully with the Lunar Reconnaissance Orbiter (LRO) from Cape Canaveral, Kennedy Space Center, June 18, 2009, 21:32:00 UTC. After LRO separation, LCROSS remained connected to the Atlas V upper-stage Centaur rocket. LCROSS completed 112 days in a Lunar Gravity Assist Lunar Return Orbit, during which on-orbit science payload calibrations, shepherding spacecraft (S-S/C) health checks, and trajectory maneuver corrections were performed. The separation maneuver of the S-S/C from the Centaur occurred on October 9, 2009, 01:50:00 UTC. The mission had two kinetic impact events: (1) the spent 2366 kg Atlas V upper-stage Centaur rocket, followed four minutes later by (2) the ~625 kg LCROSS S-S/C, both traveling at ~2.5 km/s. Impacts within the lunar south pole Cabeus crater occurred on October 9, 2009 at 11:31:19.506 UTC and 11:35:36.116 UTC, for the Centaur and S-S/C, respectively.

I will discuss the LCROSS mission, with emphasis on its non- traditional mission design, and the science data sets observed by LCROSS and other observatories. I will share all the neat things I have learned on this very hands-on and engaging project and how this type of mission concept is an excellent training experience for spacecraft engineers. I will also touch on how NASA has been expanding the concept of participatory exploration, with LCROSS as an example, and look forward to a lively discussion.

Bio:
Staff scientist at NASA Ames Research Center with special interest in
astrophysics, flight instrument design and calibration, and mission
development.

LCROSS Payload Scientist and LCROSS Payload Integration & Test Manager.

Project Scientist on the SMEX Transiting Exoplanet Survey Satellite Concept
during Phase A (2008-2009), Co-Investigator on the ASPIRE Origins Probe Mission
Concept (2004-2009) and Co-Investigator and Payload Scientist on the MIDEX
AstroBiology Explorer (ABE) Concept (2001-2008).

Serves on the Astrophysics Subcommittee of NASA’s Advisory Council and has
authored papers on infrared detector performance, infrared optical design, and
astrobiology mission concepts.

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