CONTENTS
AEA Astronomy Club Items
Picture(s) of the Month
Astronomy News
General Calendar
Colloquia, lectures, mtgs.
Observing
Useful Links
AEA Astronomy Club Items.
Calendar
• June 16 Club mtg. at 11:30am in A9/2906. Dr. Mark Morris (UCLA), “SOFIA: The Return of Airborne Astronomy” and Keck IR very high resolution observations of the galactic center, including orbits of stars about the supermassive black hole. SOFIA is the Stratospheric Observatory for Infrared Astronomy, a 2.5m aperture telescope on a 747 that just had its first light flight. Don’t miss this one – it was previewed at the Dec. SBAS mtg.
A9/2906 is the Thor Conference Room (left off the 2nd floor elevator to the end of the hall, and another left -- overlooks El Segundo Blvd.).
Other upcoming AEA Astronomy Club meeting programs (3rd Thursdays beginning in July) at 11:45am in A9/2906) & activities:
• July 15 (Thurs. 11:45am – note new day & time) – Club mtg. -- "Our Baby Universe," by David Naiditch. View the latest satellite images of the early universe, and learn what they tell us about the birth, composition, age, structure, and evolution of the universe. David also hosts the Aerospace Brown Bag series, and recently gave an excellent presentation on new telescope technologies.
• July 24 (Sat.) – Tour of Mt. Wilson (docent-guided), possibly followed by a picnic & star party. Make reservations w. David Wright, and indicate preferred starting time (between 10am and 2pm) & which parts of Mt. Wilson you’re interested in (see http://www.mwoa.org/, esp. http://www.mwoa.org/selfguide.pdf for more info), and if interested in staying for a picnic and/or star party. Non-members will be charged $5. Astronomical twilight that day ends about 9:30pm, which leaves a large gap after the latest tour ending at 4pm. By this date hopefully the normal (shorter) route will be open, and we may have our new club telescope to try out. If interested in some background in preparation, contact David Wright to check out the CD w. Don Nicholson’s historical Mt. Wilson presentation.
• Aug 19 (Thurs. 11:45am – note new day & time) – Club mtg. -- an “Overview of JPL Projects” of astronomical interest by Matt Hart, Systems Director, Flight Projects Engineering, NASA Advanced Programs Directorate.
New Club Website: https://aeropedia.aero.org/aeropedia/index.php/Astronomy_Club It is updated to reflect this newsletter, in addition to a listing of past club mtg. presentations. In the future, we may link some presentation materials from past mtgs., as well as past astronomy news & photos from the newsletters. I understand AEA clubs may be compelled before long to migrate from AeroWiki to a non-intranet site.
Membership. For information, current dues & application, contact Vic Christensen (x63021, M1-167). Benefits will include use of club telescope(s) & library/software, discounts on Sky & Telescope magazine and Observer’s Handbook, field trips, great programs, having a say in club activities, acquisitions & elections, etc.
Committee Suggestions & Volunteers. Feel free to contact: Leslie Wickman, Program Committee Chairwoman (& club VP), David Wright, the Activities Committee Chairman (& club Secretary), or Vic Christensen, Resource Committee Chairman (over equipment & library, and club Treasurer).
Astronomy Picture(s) of the Month –
The Heart and Soul nebulae are seen in this infrared mosaic from NASA's Wide-field Infrared Survey Explorer, or WISE. Image credit: NASA/JPL-Caltech/UCLA
› Full image and caption
May 24, 2010
PASADENA, Calif. -- NASA's Wide-field Infrared Survey Explorer, or WISE, has captured a huge mosaic of two bubbling clouds in space, known as the Heart and Soul nebulae. The space telescope, which has completed about three-fourths of its infrared survey of the entire sky, has already captured nearly one million frames like the ones making up this newly released mosaic.
The Heart nebula is named after its resemblance to a human heart; the nearby Soul nebula happens to resemble a heart too, but only the symbolic kind with two lobes. The nebulae, which lie about 6,000 light-years away in the constellation Cassiopeia, are both massive star-making factories, marked by giant bubbles blown into surrounding dust by radiation and winds from the stars. The infrared vision of WISE allows it to see into the cooler and dustier crevices of clouds like these, where gas and dust are just beginning to collect into new stars.
This image, combining data from two instruments aboard NASA's Mars Global Surveyor, depicts an orbital view of the north polar region of Mars. Image credit: NASA/JPL-Caltech/MSSS
› Full image and caption
May 26, 2010
PASADENA, Calif. -- Data from NASA's Mars Reconnaissance Orbiter have helped scientists solve a pair of mysteries dating back four decades and provided new information about climate change on the Red Planet.
The Shallow Radar, or SHARAD, instrument aboard the Mars Reconnaissance Orbiter revealed subsurface geology allowing scientists to reconstruct the formation of a large chasm and a series of spiral troughs on the northern ice cap of Mars.
On Earth, large ice sheets are shaped mainly by ice flow. According to this latest research, other forces have shaped, and continue to shape, polar ice caps on Mars. The northern ice cap is a stack of ice and dust layers up to two miles deep, covering an area slightly larger than Texas. Analyzing radar data on a computer, scientists can peel back the layers like an onion to reveal how the ice cap evolved over time.
One of the most distinctive features of the northern ice cap is Chasma Boreale, a canyon about as long as Earth's Grand Canyon but deeper and wider. Some scientists believe Chasma Boreale was created when volcanic heat melted the bottom of the ice sheet and triggered a catastrophic flood. Others suggest strong polar winds carved the canyon out of a dome of ice.
Other enigmatic features of the ice cap are troughs that spiral outward from the center like a gigantic pinwheel. Since the troughs were discovered in 1972, scientists have proposed several hypotheses about how they formed. Perhaps as Mars spins, ice closer to the poles moves slower than ice farther away, causing the semi-fluid ice to crack. Perhaps, as one mathematical model suggests, increased solar heating in certain areas and lateral heat conduction could cause the troughs to assemble.
Data from Mars now points to both the canyon and spiral troughs being created and shaped primarily by wind. Rather than being cut into existing ice very recently, the features formed over millions of years as the ice sheet grew. By influencing wind patterns, the shape of underlying, older ice controlled where and how the features grew.
Astronomy News:
A Long Eclipse on Epsilon Aurigae. The Mt. Wilson CHARA interferometric array has seen a giant, oblong disk begin a partial eclipse of the giant (1.3 A.U. or 2 milliarcseconds diameter) star. It began in Nov. 2009, and is predicted to last until May 2011, meaning the eclipsing disk (protoplanetary or debris around a yet-unborn companion star or brown dwarf?) would be about 10 A.U. long – about the diameter of Jupiter’s orbit.
The Spin on Black Holes. A Penn State group has related black hole spin to its mass and the power of any jet emitted. Studying 55 supermassive holes at centers of galaxies, they found them spinning from 10% to 100% of the maximum possible spin rate, limited by the speed of light. The more distant ones that we see as they were young spin faster than the nearby ones which have spun down due to accretion of counterrotating material.
[The above 2 news bites are from the July 2010 issue of Sky & Telescope Magazine. Below is a recap of email news releases forwarded to club members by Vic Christensen, not including the Scientific American articles.]
Date Description URL
11 May 10 The Herschel Space Observatory has made an unexpected discovery: a gaping hole in the clouds surrounding a batch of young stars. The hole has provided astronomers with a surprising glimpse into the end of the star-forming process. http://www.jpl.nasa.gov/news/news.cfm?release=2010-155&cid=release_2010-155
11 May 10 It appears flash flooding has paved streambeds in the Xanadu region of Saturn's moon Titan with thousands of sparkling crystal balls of ice, according to scientists with NASA's Cassini spacecraft. http://www.jpl.nasa.gov/news/news.cfm?release=2010-156&cid=release_2010-156
11 May 10 Astronomers are a bit like archeologists as they dig back through space and time searching for remnants of the early universe. In a recent deep excavation, courtesy of NASA's Spitzer Space Telescope, astronomers unearthed what may be the most distant, primitive cluster of galaxies ever found. http://www.jpl.nasa.gov/news/news.cfm?release=2010-157&cid=release_2010-157
12 May 10 Innovative planetarium shows and traveling museum exhibits are among nine projects NASA has selected to receive agency funding this year. NASA's Competitive Program for Science Museums and Planetariums will provide $7 million in grants to enhance educational outreach related to space exploration, aeronautics, space science, Earth science and microgravity. http://www.jpl.nasa.gov/news/news.cfm?release=2010-160&cid=release_2010-160
19 May 10 NASA's Mars Exploration Rover Project will pass a historic Martian longevity record on Thursday, May 20. The Opportunity rover will surpass the duration record set by NASA's Viking 1 Lander of six years and 116 days operating on the surface of Mars. http://www.jpl.nasa.gov/news/news.cfm?release=2010-168b&cid=release_2010-168b
20 May 10 Our sun may be an only child, but most of the stars in the galaxy are actually twins. The sibling stars circle around each other at varying distances, bound by the hands of gravity. http://www.jpl.nasa.gov/news/news.cfm?release=2010-170&cid=release_2010-170
20 May 10 Planners of NASA's next Mars mission have selected a flight schedule that will use favorable positions for two currently orbiting NASA Mars orbiters to obtain maximum information during descent and landing. http://www.jpl.nasa.gov/news/news.cfm?release=2010-171&cid=release_2010-171
24 May 10 NASA's Wide-field Infrared Survey Explorer, or WISE, has captured a huge mosaic of two bubbling clouds in space, known as the Heart and Soul nebulae. http://www.jpl.nasa.gov/news/news.cfm?release=2010-174&cid=release_2010-174
24 May 10 NASA's Phoenix Mars Lander has ended operations after repeated attempts to contact the spacecraft were unsuccessful. A new image transmitted by NASA's Mars Reconnaissance Orbiter shows signs of severe ice damage to the lander's solar panels. http://www.jpl.nasa.gov/news/news.cfm?release=2010-175&cid=release_2010-175
24 May 10 NASA's Wide-field Infrared Survey Explorer, or WISE, is busy surveying the landscape of the infrared sky, building up a catalog of cosmic specimens -- everything from distant galaxies to "failed" stars, called brown dwarfs.
http://www.jpl.nasa.gov/news/news.cfm?release=2010-176&cid=release_2010-176
26 May 10 Data from NASA's Mars Reconnaissance Orbiter have helped scientists solve a pair of mysteries dating back four decades and provided new information about climate change on the Red Planet. http://www.jpl.nasa.gov/news/news.cfm?release=2010-180&cid=release_2010-180
27 May 10 Hurricanes, air quality and Arctic ecosystems are among the research areas to be investigated during the next five years by new NASA airborne science missions announced today. http://www.jpl.nasa.gov/news/news.cfm?release=2010-182&cid=release_2010-182
1 Jun 10 Going against the grain may turn out to be a powerful move for black holes. New research suggests supermassive black holes that spin backwards might produce more ferocious jets of gas. The results have broad implications for how galaxies change over time. http://www.jpl.nasa.gov/news/news.cfm?release=2010-186&cid=release_2010-186
General Calendar:
Colloquia, Lectures, Seminars & Meetings:
Colloquia: Carnegie (Tues. 4pm), UCLA, Caltech (Wed. 4pm), IPAC (Wed. 12:15pm) & other Pasadena (daily 12-4pm): http://obs.carnegiescience.edu/seminars/
4 June SBAS monthly general mtg., SBAS members astrophotography competition, El Camino College. 7:30pm, El Camino College Planetarium, 16007 Crenshaw Blvd., Torrance
June 10 & 11 The von Kármán Lecture Series – CATASTROPHE and Earth's Evolution: When Bad Things Happen to Good Planets
Life on Earth has evolved as a consequence of the evolution of Earth itself. The Earth of the present is clearly not the same planet that it was when it first formed, but its metamorphosis into the habitable environment we enjoy today was not always gradual and benign. Several catastrophic events have occurred that have served both as opportunity and threat. In this talk we will look at a series of cataclysmic events that have shaped the Earth we know and love, and we will speculate about what may lie ahead.
Speaker: Dr. Pamela Conrad, Science Division, JPL
Location: Thursday, June. 10, 2010, 7pm
The von Kármán Auditorium at JPL
4800 Oak Grove Drive
Pasadena, CA
› Directions
Friday, June. 11, 2010, 7pm
The Vosloh Forum at Pasadena City College
1570 East Colorado Blvd.
Pasadena, CA
› Directions
6/14/2010 (Mon) LAAS General Meeting
Griffith Observatory
Event Horizon Theater
7:45 PM to 9:45 PM
Carnegie astronomy lectures – only 4 per year in the Spring www.obs.carnegiescience.edu. Visit www.huntington.org for directions.
June 16 Club mtg. at 11:30am in A9/2906. Dr. Mark Morris (UCLA), “SOFIA: The Return of Airborne Astronomy” and Keck IR very high resolution observations of the galactic center, including orbits of stars about the supermassive black hole. SOFIA is the Stratospheric Observatory for Infrared Astronomy, a 2.5m aperture telescope on a 747 that will begin operations this year. Don’t miss this one – it was previewed at the Dec. SBAS mtg.
Sunday, June 27, MWOA Free Public Lecture -- Jed Laderman, astronomy teacher and MWOA Board member, to speak on Iceland and its volcanoes. In the Community Room of the Altadena Public Library. Refreshments are at 2:00pm, the program begins at 2:30pm. See the Lectures page for more details. See the Directions page for how to get to the Altadena Public Library.
Observing:
5 June SBAS star party (weather permitting): RPV at Ridgecrest Middle School 28915 North Bay Rd.
12 June SBAS out-of-town observing – contact Greg Benecke www.sbastro.org.
6/12/2010 (Sat) LAAS Dark Sky Night
Lockwood Valley (Steve Kufeld Astronomical site)
June 13 new moon
15/16 June – Lyrids meteor shower peak (up to 8/hour).
June 21 Summer solstice
6/19/2010 (Sat) LAAS Public Star Party
Griffith Observatory
2:00 p.m. to 10:00 p.m.
More details are provided in the bulletin.
July 11 total solar eclipse crosses Easter Island, Chile.
Dec. 21 total lunar eclipse for Western Hemisphere
Internet Links:
AEA Astronomy Club Intranet site: https://aeropedia.aero.org/aeropedia/index.php/Astronomy_Club
So. Calif. astronomy organizations, observatories & planetaria: http://www.mwoa.org/local.html
MWOA (Mt. Wilson Observatory Assn.), including status for visits & roads: www.mwoa.org
Western Amateur Astronomers (consortium of various regional societies): www.waa.av.org/Club_members.html
LAAS list of links (incl. Tools, Journals, Vendors, Other Societies, Databases, Members) http://www.laas.org/Links.htm
LAAS (L.A. Astronomical Society -- www.laas.org)
SBAS (South Bay Astronomical Soc. . -- www.sbastro.org)
Mark Clayson,
AEA Astronomy Club President
:
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2010 May Newsletter
CONTENTS
AEA Astronomy Club Items
Astronomy News
Picture(s) of the Day
General Calendar
Useful Links
AEA Astronomy Club Items.
Calendar
• May 19 Club mtg. at 11:30am in A9/2906. “A Grand Tour of the Universe” slideshow, including Hubble, Chandra, Spitzer & other recent photos & explanations by one of our own degreed astronomers, Mark Clayson.
A9/2906 is the Thor Conference Room (left off the 2nd floor elevator to the end of the hall, and another left -- overlooks El Segundo Blvd.).
Other upcoming AEA Astronomy Club meeting programs (3rd Wednesday at 11:30 in A9/2906) & activities:
• June 16 – Club mtg. w. Dr. Mark Morris (UCLA), “SOFIA: The Return of Airborne Astronomy” and Keck IR very high resolution observations of the galactic center, including orbits of stars about the supermassive black hole. SOFIA is the Stratospheric Observatory for Infrared Astronomy, a 2.5m aperture telescope on a 747 that will begin operations this year. Don’t miss this one – it was previewed at the Dec. SBAS mtg.
• TBD (when road reopens) – a Saturday Tour of Mt. Wilson (docent-guided) , possibly followed by a picnic & star party
New Club Website: https://aeropedia.aero.org/aeropedia/index.php/Astronomy_Club
Membership. For information, current dues & application, contact Vic Christensen (x63021, M1-167). Benefits will include use of club telescope(s) & library/software, discounts on Sky & Telescope magazine and Observer’s Handbook, field trips, great programs, having a say in club activities, acquisitions & elections, etc.
Committee Suggestions & Volunteers. Feel free to contact: Leslie Wickman, Program Committee Chairwoman (& club VP), David Wright, the Activities Committee Chairman (& club Secretary), or Vic Christensen, Resource Committee Chairman (over equipment & library, and club Treasurer).
Astronomy News:
“Some argue that…” in its short 20 years, the Hubble Space “…Telescope (HST) has had a similarly profound impact on astronomical research as …Galileo’s small telescope 400 years ago.” In addition to impressive PR & education for science & astronomy, with 44.34 terabytes of high resolution data, it has resulted in 8,736 scientific papers to date. Here are what some “…regard as the top five scientific discoveries in which HST played a crucial role.”
Dark Energy & Fate of the Universe. In 1998, answering a long-standing question of the future of the universe, HST evidence showed “…the expansion of the universe is accelerating.” This “…was based primarily on the faintness of Type Ia supernovae [bright, constant luminosity] at red-shifts of around 0.5, compared to their expected brightness in a universe decelerating under its own gravity.” This appears to be due to a dark energy comprising about 73% of the universe’s mass-energy budget. Hubble also indicated that: the transition from deceleration to acceleration occurred around 5 billion years ago; dark energy was present 9 billion yrs ago, though not yet dominant; and it’s consistent with quantum mechanical predictions for vacuum energy.
The Hubble Constant & Age of the Universe. Edwin Hubble found (at Mt. Wilson) in the late 1920’s that the universe is expanding. The current expansion rate -- known as the Hubble constant -- and hence the age of the universe, was uncertain to a factor of 2 prior to HST. HST’s resolution allowed isolated measurements of Cepheid variable stars in dozens of galaxies. Cepheid brightness is well-correlated with their period, permitting precise distance determination. And spectral redshifts determine relative velocity. This has reduced the Hubble constant error to under 5%: 74.2 +/- 3.6 km/sec/megaparsec, and the age of the universe 13.75 +/- 0.11 billion years.
Galaxy Formation and Evolution. In its “Deep Field” survey, HST has resolved galaxies over 13 billion light years distant (redshift ~7-8), whose light left when the universe was only some 600 million years old. Compared with the older, nearby galaxies we see, the young galaxies were smaller and more irregularly shaped. This tends to indicate that “…smaller galaxy building blocks collided frequently and accreted cold gas when the universe was smaller and denser.” Early galaxies appear extremely blue, as expected if the metal content (elements heavier than helium), and the amount of dust, were very low. The survey also indicates the rate of star formation increased from that time, peaking about 5 billion years after the Big Bang, and has been declining since. And the Ultra-Deep Field observations indicate that stars & protogalaxies/quasars beginning to appear at 100 million years began to ionize the previously neutral (since 380,000 yrs.) intergalactic gas, and reionization was complete by 1 billion years. “HST has established that quasar hosts are indeed galaxies … bright ellipticals or interacting galaxies.” HST galactic center observations indicate most galaxies have supermassive (to a few billion Suns) black holes, and that their mass is correlated with the mass of the stellar bulges at galaxy centers. HST has shown that long-duration gamma-ray bursts (GRBs) likely “…come from massive stars collapsing to form black holes.”
Extrasolar Planets. In 1995 the first planet outside our solar system (around another star) was detected, and since then about 440 “exoplanets” are known. In 2004, HST made the first image of an exoplanet -- orbiting Fomalhaut (confirmed in subsequent years with orbital motion). About 70 exoplanets are transiting – they cross between us and their star, dimming the starlight 1-2% for gas giants. A small part of that dimming is due to absorption in the planet’s atmosphere, and composition is found measuring spectral lines. HST has found the atmospheric composition of 2 planets. HD 209458b contains sodium, oxygen, carbon & hydrogen. HD 189733b has CO2, water & methane. HST also found that the frequency of planets in the Milky Way’s central bulge is similar to that in our spiral arm neighborhood, indicating “…that our galaxy is probably teeming with billions of planets.”
Dark Matter. HST’s resolution has permitted gravitational lensing (relativistic effect due to the mass of galactic clusters) of background galaxies “…to reconstruct the large-scale, three-dimensional distribution of the dark matter responsible for the distortions.” Looking 3.5, 5.0 & 6.5 billion years ago in one direction, astronomers “…found that dark-matter clumping becomes more pronounced over time.” Observing the collision of two galaxy clusters, HST & Chandra X-ray show “…hot gas in the two clusters interacts strongly, producing a shock front, while the dark matter completely separates from the gas….what we expect from very weakly interacting particles.”
This is only a sampling – HST has made many other discoveries, within and beyond the solar system and galaxy.
[from “Hubble’s Greatest Scientific Achievements,” Mario Livio, June 2010 Sky & Telescope]
Astronomy Picture of the Day –
New view of dusty spires marks Hubble's 20th birthday
CLICK TO ENLARGE + NASA, ESA, and M. Livio and the Hubble 20th Anniversary Team (STScI)
The Hubble Space Telescope passed its 20th anniversary of reaching orbit on April 24, an occasion marked with the release of a new image from the venerable observatory, depicting a star-forming region of the Milky Way some 7,500 light-years away called the Carina Nebula.
The pillars in Hubble's new image, which was captured by the telescope in February, are dusty plumes of gas undergoing erosion from the radiation and stellar winds of young, nearby stars. According to a NASA press release, the main pillar is three light-years high, although this photograph depicts only its top segment.
The new release recalls Hubble's famous 1995 image, known as "The Pillars of Creation," showing similar features in the Eagle Nebula. But whereas that image came from Hubble's old Wide Field Planetary Camera 2 (WFPC2), the photograph of the Carina spires was produced by the more advanced Wide Field Camera 3 (WFC3). Spacewalking astronauts swapped in WFC3 for its aging predecessor during the final scheduled servicing mission to Hubble in May 2009.
[Note what appear to be bi-polar jets emanating from the tops of the two largest columns – indicative no doubt of 2 protostars there, with jets aligned with their spin axes & perpendicular to their protoplanetary disks.]
General Calendar:
5/6 May – Eta Aquarids meteor shower peak (up to 10/hour) – remnants of comet Halley.
SBAS (South Bay Astronomical Soc. . -- www.sbastro.org ) Events:
7 May SBAS monthly general mtg., Guest Speaker: Michael Harrison Topic: Star Testing Your Telescope, El Camino College. 7:30pm, El Camino College Planetarium, 16007 Crenshaw Blvd., Torrance
8 May SBAS star party (weather permitting): RPV at Ridgecrest Middle School 28915 North Bay Rd.
15 May SBAS out-of-town observing – contact Greg Benecke www.sbastro.org.
LAAS Events: (L.A. Astronomical Society -- www.laas.org)
5/10/2010 (Mon) General Meeting
Griffith Observatory
Event Horizon Theater
7:45 PM to 9:45 PM
5/15/2010 (Sat) Dark Sky Night
Lockwood Valley (Steve Kufeld Astronomical site)
5/22/2010 (Sat) Public Star Party
Griffith Observatory
2:00 p.m. to 10:00 p.m.
More details are provided in the bulletin.
Carnegie astronomy lectures will be held on
May 17: Janice Lee, Ph.D., Carnegie Fellow, Carnegie Observatories
Meet the Galaxy's Neighbors
The Milky Way lives in a quiet suburb of the Universe. However, the galaxies in our local neighborhood are not without an intriguing past. What kinds of galaxies populate the volume of space surrounding the Milky Way and where did they come from? Dr. Lee is leading a study which is providing the most complete census of local galaxies to-date, and will discuss how astronomers learn the answers to such questions.
at 7:30 PM in the Huntington Gardens. For more information, go to: obs.carnegiescience.edu. Free and open to the public. Visit www.huntington.org for directions. Please call 626-304-0250 for more information on these popular lectures.
• May 19 Aerospace Astronomy Club mtg. at 11:30am in A9/2906. “A Grand Tour of the Universe” slideshow, including Hubble, Chandra, Spitzer & other recent photos & explanations by one of our own degreed astronomers, Mark Clayson.
The von Kármán Lecture Series – None scheduled in May
Monday, May 24, 2010 Aerospace Brown-Bag Talk: New Telescope Technologies
Over the past few decades, the power of telescopes has dramatically increased. Technologies such as optical interferometry, segmented mirrors, charge-coupled devices (CCDs), space-based platforms, and adaptive optics have emerged to allow telescopes to see further, detect fainter objects, and observe finer details.
Speaker: David Naiditch Time: Noon to 1:00 pm Location: A3 Dining Room A & B
July 11 total solar eclipse crosses Easter Island, Chile.
Dec. 21 total lunar eclipse for Western Hemisphere
Internet Links:
AEA Astronomy Club Intranet site: https://aeropedia.aero.org/aeropedia/index.php/Astronomy_Club
So. Calif. astronomy organizations, observatories & planetaria: http://www.mwoa.org/local.html
MWOA (Mt. Wilson Observatory Assn.), including status for visits & roads: www.mwoa.org
Western Amateur Astronomers (consortium of various regional societies): www.waa.av.org/Club_members.html
LAAS list of links (incl. Tools, Journals, Vendors, Other Societies, Databases, Members) http://www.laas.org/Links.htm
Mark Clayson,
AEA Astronomy Club President
:
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2010 April Newsletter
CONTENTS
AEA Astronomy Club Items
Astronomy News
Picture(s) of the Day
General Calendar
Useful Links
AEA Astronomy Club Items.
Calendar
• April 21 Club mtg. at 11:30am in A9/2906. Debra Emmons, Systems Director, Independent Assessment, NASA Advanced Programs Directorate, will be substituting for David Bearden to speak on the Augustine Commission, especially Aerospace support. We’ll hear about current directions in manned space exploration.
A9/2906 is the Thor Conference Room (left off the 2nd floor elevator to the end of the hall, and another left -- overlooks El Segundo Blvd.).
Other upcoming AEA Astronomy Club meeting programs (3rd Wednesday at 11:30 in A9/2906) & activities:
• May 19 – “A Grand Tour of the Universe” slideshow, including Hubble, Chandra, Spitzer & other recent photos & explanations by one of our own degreed astronomers, Mark Clayson.
• TBD (when road reopens) – a Saturday Tour of Mt. Wilson (docent-guided) , possibly followed by a picnic & star party
Membership. For information, current dues & application, contact Vic Christensen (x63021, M1-167). Benefits will include use of club telescope(s) & library/software, discounts on Sky & Telescope magazine and Observer’s Handbook, field trips, great programs, having a say in club activities, acquisitions & elections, etc.
Committee Suggestions & Volunteers. Feel free to contact: Leslie Wickman, Program Committee Chairwoman (& club VP), David Wright, the Activities Committee Chairman (& club Secretary), or Vic Christensen, Resource Committee Chairman (over equipment & library, and club Treasurer).
Astronomy News:
[from Sky & Telescope News Notes, April & May 2010]
Shedding Light on Dark Matter
Dark matter makes up about 22% of the universe’s total matter-and-energy density (compared w. ~4% conventional (baryonic) matter), and doesn’t interact w. normal matter except gravitationally (e.g., no electromagnetic or light interaction). One evidence of it is the near constant rather than decreasing velocities of stars with distance from the center of galaxies, indicating a dark matter halo extending beyond the detectable, normal matter.
The “Sagittarius Stream” is the flung-out remnant of a dwarf galaxy’s close encounter with ours, and loops all around the Milky Way, outside its fringes. UCLA analysis of the motions of thousands of stars in it indicate that “...the Milky Way’s dark matter halo is not spherical, but flattened in 3 directions into a triaxial shape, like a squashed football.” The flattest side is oddly perpendicular to the normal matter disk.
U. Maryland analysis shows that the smaller a galaxy, the larger its proportion of dark matter. The ratio in the cosmos as a whole is about 5 to 1, which holds true in the largest galaxy clusters. But in smaller cosmic structures like dwarf galaxies, it can exceed 100 to 1. One theory is that small (less mass & gravity) galaxies were less able to hold onto their gas early on when supernovae were more common. The supernovae may have cleared out most of the normal matter, ending most star formation, but the dark matter wouldn’t interact with the blast waves, so was left behind.
Dark Energy Update
The expansion of the universe is accelerating due to an unknown, anti-gravity “dark energy” that makes up about 74% of the matter-and-energy budget of the universe. Until now, the effect has only been observed at the largest scales, studying galaxies billions of light years distant. A U. Alabama group has now seen the effect on a smaller scale within the Local Group of galaxies. They found “...a boundary exists where the Local Group’s gravity gives way to dark energy’s “antigravity” effect on larger scales. Dwarf galaxies that lie beyond this boundary are moving outward – cosmic acceleration in miniature.”
Double Supermassive Black Holes
Nearly every large galaxy apparently has a supermassive black hole at its center, with from 1 million to 20 billion times the mass of the Sun (determined by orbits of nearby stars). They likely play a key role in regulating the size of a galaxy, e.g. via the associated jets early on. And we know that galaxies often collide and merge, so many galaxies might be expected to have two or more such huge black holes. Until recently, clear examples were hard to find, but a UC Berkely group has announced 33 galaxies with two such holes -- “...much more common than previously known.”
Astronomy Picture of the Day –
Ashes to Ashes, Dust to Dust: Chandra/Spitzer Image
A composite image from NASA's Chandra (blue) and Spitzer (green and red-yellow) space telescopes shows the dusty remains of a collapsed star, a supernova remnant called G54.1+0.3. Image credit: NASA/CXC/JPL-Caltech/Harvard-Smithsonian CfA
› Full image and caption
March 29, 2010
PASADENA, Calif. -- A new image from NASA's Chandra and Spitzer space telescopes shows the dusty remains of a collapsed star. The dust is flying past and engulfing a nearby family of stars.
"Scientists think the stars in the image are part of a stellar cluster in which a supernova exploded," said Tea Temim of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass., who led the study. "The material ejected in the explosion is now blowing past these stars at high velocities."
The composite image of G54.1+0.3 is online at http://photojournal.jpl.nasa.gov/catalog/?IDNumber=pia12982 . It shows the Chandra X-ray Observatory data in blue, and data from the Spitzer Space Telescope in green (shorter wavelength) and red-yellow (longer). The white source near the center of the image is a dense, rapidly rotating neutron star, or pulsar, left behind after a core-collapse supernova explosion. The pulsar generates a wind of high-energy particles -- seen in the Chandra data -- that expands into the surrounding environment, illuminating the material ejected in the supernova explosion.
2010 April 6
A Fox Fur, a Unicorn, and a Christmas Tree
Credit & Copyright: Kerry-Ann Lecky Hepburn (Weather and Sky Photography) & Stefano Cancelli (AstroGarage)
Explanation: What do the following things have in common: a cone, the fur of a fox, and a Christmas tree? Answer: they all occur in the constellation of the unicorn (Monoceros). Pictured above as a star forming region cataloged as NGC 2264, the complex jumble of cosmic gas and dust is about 2,700 light-years distant and mixes reddish emission nebulae excited by energetic light from newborn stars with dark interstellar dust clouds. Where the otherwise obscuring dust clouds lie close to the hot, young stars they also reflect starlight, forming blue reflection nebulae. The wide mosaic spans about 3/4 degree or nearly 1.5 full moons, covering 40 light-years at the distance of NGC 2264. Its cast of cosmic characters includes the Fox Fur Nebula, whose convoluted pelt lies at the upper left, bright variable star S Mon immersed in the blue-tinted haze just below the Fox Fur, and the Cone Nebula at the far right. Of course, the stars of NGC 2264 are also known as the Christmas Tree star cluster. The triangular tree shape traced by the stars appears sideways here, with its apex at the Cone Nebula and its broader base centered near S Mon.
General Calendar:
10 April (Sat.) – 11-12pm on PBS (KCET) “400 Years of the Telescope” 7 Awards, “Beautifully photographed in 4K digital cinematography, this film is a visually stunning chronicle of the history of the telescope from the time of Galileo, its profound impact upon the science of astronomy, and how both shape the way we view ourselves in the midst of an infinite universe.” Book & DVD available from shopPBS.org, iTunes, Amazon & Barnes & Noble. “Watch for our companion planetarium show, ‘Two Small Pieces of Glass,’ playing at a theater near you.”
IMAX “Hubble 3D” now playing at select IMAX and IMAX 3D theatres.
2 April -- SBAS (South Bay Astronomical Soc.) monthly general mtg., 3rd Annual SBAS Astrophotography Contest, El Camino College. 7:30pm, El Camino College Planetarium, 16007 Crenshaw Blvd., Torrance. www.sbastro.org
10 April -- SBAS star party (weather permitting): RPV at Ridgecrest Middle School 28915 North Bay Rd.
17 April SBAS out-of-town observing – contact Greg Benecke www.sbastro.org.
Carnegie astronomy lectures will be held on
April 12: Jenny Greene, Ph.D., Carnegie-Princeton Fellow, Princeton University
Tiny but Powerful
Supermassive black holes, with masses of millions to billions of times that of our own Sun, are found lurking at the centers of most nearby large galaxies. But which came first, the black hole or the galaxy? Dr. Greene will talk about the search for the smallest supermassive black holes in existence today, and what they teach us about the very first black holes.
- April 19: Vera Rubin, Ph.D., Senior Fellow, Department of Terrestrial Magnetism, Carnegie Institution for Science
Bright Galaxies and Dark Matter
We live in a Universe that is incredibly large and surprisingly complex. Yet one of its many remarkable features is that we understand some of it! Dr. Rubin will describe how astronomers learned that most of the matter in the Universe is dark, not visible at any wavelength. This fact should ultimately teach us fundamental new features about our Universe.
at 7:30 PM in the Huntington Gardens. For more information, go to: obs.carnegiescience.edu. Free and open to the public. Visit www.huntington.org for directions. Please call 626-304-0250 for more information on these popular lectures.
21 April Aerospace Astronomy Club mtg. 11:30am, A9/2906 -- Debra Emmons, Systems Director, Independent Assessment, NASA Advanced Programs Directorate, will be substituting for David Bearden to speak on the Augustine Commission, especially Aerospace support.
The von Kármán Lecture Series – Mapping the Infrared Sky with WISE by Dr. Peter Eisenhardt.
The Wide-field Infrared Survey Explorer (WISE) launched December 14, 2009, and a month later began surveying the sky in four infrared wavelengths, ranging from four to 30 times redder than our eyes can see. WISE continues the JPL/Caltech tradition of mapping the infrared sky. Its megapixel infrared detector arrays make the WISE survey hundreds to hundreds of thousands of times more sensitive than previous all-sky surveys using only dozens of pixels. The satellite is observing everything in the Universe from near-Earth asteroids to dusty, cataclysmically forming galaxies over 10 billion light years away, and is expected to discover hundreds, to perhaps thousands, of new objects.
Thursday, April 15, 2010, 7pm
The von Kármán Auditorium at JPL
4800 Oak Grove Drive
Pasadena, CA
› Directions
Friday, April 16, 2010, 7pm
The Vosloh Forum at Pasadena City College
1570 East Colorado Blvd.
Pasadena, CA
› Directions
LAAS Events: (L.A. Astronomical Society -- www.laas.org)
4/10/2010 (Sat) Dark Sky Night
Lockwood Valley (Steve Kufeld Astronomical site)
4/12/2010 (Mon) General Meeting
Griffith Observatory
Event Horizon Theater
7:45 PM to 9:45 PM
4/24/2010 (Sat) Public Star Party
Griffith Observatory
2:00 p.m. to 10:00 p.m.
More details are provided in the bulletin.
July 11 total solar eclipse crosses Easter Island, Chile.
Dec. 21 total lunar eclipse for Western Hemisphere
Internet Links:
So. Calif. astronomy organizations, observatories & planetaria: http://www.mwoa.org/local.html
MWOA (Mt. Wilson Observatory Assn.), including status for visits & roads: www.mwoa.org
Western Amateur Astronomers (consortium of various regional societies): www.waa.av.org/Club_members.html
LAAS list of links (incl. Tools, Journals, Vendors, Other Societies, Databases, Members) http://www.laas.org/Links.htm
Mark Clayson,
AEA Astronomy Club President
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