MARCH 2007 The Denver Newsletter of the Denver Astronomical Society One Mile Nearer the Stars The Greatest of the Great Magnificent M42 (NGC 1976) lies about 1,500 light-years from our sun. The Great Nebula in Orion is easily one of the most observed objects in the skies. Be sure to read Stuart Hutchins’ article on Image copyright 2007 Philip Good Page 3 for more information. Contact Philip Good for image details. MARATHON TIME! MARCH SKIES he month of March opens with a lunar scopes will show the disk of Venus more than President’s Corner .................... 2 Teclipse but, unfortunately, it will be vis- 80% illuminated and an apparent magnitude ible only to those in the eastern U.S. However, Mv -4.0. Recall early last month that Mercury Venus continues its rise in the western sky, set- was visible to the lower right of Venus at sun- Schedule of Events ................... 2 ting more than three hours after sunset. Tele- set, however, on the 22nd Mercury reaches its MARCH PREDOMINANT CELESTIAL OBJECTS Society Directory ..................... 2 Description RA DEC Description RA DEC γ ° ° Observer Andromedae, double star 02h 03.9m 42 20' Pleiades 03h 47.5m 24 06' Feature Article .................. 3, 6-7 Mira, Variable star 02h 19.7m -2° 57' M42, Orion nebula 05h 35.4m -5° 22' Perseus double cluster 02h 21.5m 57° 08' σ Orionis, multiple star 05h 38.7m -2° 35' ι Cassiopeiae, triple star 02h 29.0m 67° 24' M35 cluster 06h 08.9m 24° 21' Messier Marathon.................4-5 M77, Spiral galaxy 02h 43.0m 0° 01' Castor, double star 07h 34.6m 31° 54' M81 galaxy 09h 55.6m 69° 04' Banquet Info ........................... 7 3 ................. Full moon (AKA “Old Moon”) greatest western elongation and will be visible 11 .............................. Last quarter moon to early morning risers less than an hour be- 18 ......................................... New moon fore sunrise. Mercury and Venus both go Membership Info ........ back page 20 . Spring or Vernal equinox (18:07 MDT) through phases similar to that of the Moon. 25 .............................. First quarter moon Continued on page 5 MarchInside The 2007 One Mile Nearer the Stars Page 1 Society Directory President’s Corner President: he elections have passed, and we’re Wayne Green (303) 530-1023 looking forward to DAS’s next Astro Email: [email protected] Vice President: nomical Year. This year we will focus T Darrell Dodge (303) 932-1309 on the Edmund G. Kline Dark Site and on Email: [email protected] extending outreach to schools. With increas- Secretary: ing light encroachment on our weekday ob- Stuart Hutchins (303) 697-4353 serving sites, everyone is having to travel far- Email: [email protected] ther afield to get to dark skies. It helps to be Treasurer: ready with your observing program to maxi- Brad Gilman (720) 488-1028 mize your time at the site. To this end, we are Email: [email protected] looking to start observing programs locally. These will be at Chamberlin on our public Executive Board Members outreach days, backyards around the metro Jack Eastman Ron Pearson area, and at the Dark Site. Joe Gafford Keith Poole This is not to say that your backyard should Frank Mancini David Shouldice Ron Mickle Dan Wray be ignored. Some members are getting excel- Wayne Green, President of the Denver lent results from backyards, even those imme- Astronomical Society. Steve Solon, Past President diately adjacent to car dealerships. I live on the President Emeritus, Larry Brooks north end of town and have good access to improvements to the observatory’s decor, greatly northern skies. Those who live along the south- helping us conduct our open house and public Committees ern end still have pretty good southern skies. night events. Eventually, Dr. Howe’s office will ALCor: Lights from new construction along I-25 near become a conference room. There is no news Jerry Sherlin (303) 680-6894 Fort Collins is spilling to the east. The expan- about the State Historic Fund Grant at this Email: [email protected] EGK Dark Site Chair: sion of new houses in Douglas County is be- time. DU has a new person handling the grant, Wayne Kaaz (303) 840-1549 ing felt to the south. DAS recently renewed and we hope this will help get the work started. Email: [email protected] our membership with IDA, The Banquet is coming up fast! It is on March IDA Representative: and we are looking into 3 at the White Fence Farm. With 90 Dr. Robert Stencel Public Outreach: ways to support dark sky reservations,we get the large banquet room. Ron Mickle initiatives along the Front This will let us have a great feast and give Dr. Restoration and Maintenance: Range. John Steven’s some pacing room for his talk Ron Pearson There are new book- about Lockheed Martin’s role with Orion, Finance: Frank Mancini shelves in the Director’s Office Van Nattan Scholarship Fund at Chamberlin. This is the first step to making Continued on page 7 P.O. Box 150743 Lakewood, Colorado 80215-0743 Colorado Astronomy Day: Darrell Dodge MARCH APRIL Annual Picnic: Keith Pool Newsletter: 2 E-Board meeting at Chamberlin 6 General Membership Meeting Observer editor, Patti Kurtz Observatory (Begins at 7:30 P.M.) at D.U.’s Olin Hall (Begins at Email: [email protected] (720) 217-5707 3 DAS Spring Banquet at the 7:30 P.M.) The Observer is available in color PDF format from White Fence Far, (Begins at 6:00 14-15 EGK Dark Site Weekend the DAS website. Website: P.M.) 21 National Astronomy Day #1 Darrell Dodge and Patti Kurtz 11 Daylight Savings Time starts Open House at Chamberlin (2:00 A.M.) Observatory (Begins at 7:30 P.M.) DAS Information Line: 17-18 EGK Dark Site Weekend 27 E-Board meeting at Chamberlin (303) 871-5172 DAS Correspondence: (Messier Marathon) Observatory (Begins at 7:30 P.M.) Denver Astronomical Society 24 Open House at Chamberlin Chamberlin Observatory C/O Wayne Green Observatory (Begins at 5:00 P.M.) 2930 East Warren Avenue Denver, Colorado 80210 Public nights are held every Tuesday and Thursday evenings beginning at the following times: October 1 - March 31 at 7:00 P.M. The Executive Board conducts the business of the DAS at April 1 - September 30 at 8:30 P.M. at Chamberlin Observatory 8 P.M. at Chamberlin Observatory. Please see the Costs to non-members are: $3.00 adults, $2.00 children. Schedule of Events for meeting dates. All members are Please call (303) 871-5172 for reservations. welcome. DAS Schedule thedas.org Page 2 The Denver Observer March 2007 Orion’s Great Astrophysics Laboratory by Stuart Hutchins did a search of the APOD archives for “orion nebula” and turned up the images and science information outlined below. Many more are on the site for you to explore. The size of this 100 light year wide cloud is shown more clearly in this picture by renowned imager Robert Gendler, using a CCD camera. The Great Nebula (lower right in the image) is merely a 13 ly wide bright blister burned out of the near side of the cloud by the four young massive stars of the Trapezium, which are eas- ily seen in amateur telescopes. The huge cloud is dark and opaque, and we see only the sur- Orion on Film face glowing in H-alpha where it is ionized by Credit & Copyright: Mathew Spinelli ultraviolet radiation. Blue reflection nebulae surround the bright stars. All this situated in - rion, the Hunter, strides larger than life you guessed it - the Orion arm of the Milky O across the northern winter sky, studded Way, which also contains Earth’s solar system. with bright stars. After the Big Dipper, he is At a distance of 1500 ly, this is the nearest stel- probably the most recognized constellation in lar nursery to Earth, and the most studied by the northern skies. Every young boy loves a astronomers. Hubble images at other wave- star named “Beetle Juice”, and even binocular lengths and infrared light reveal a fantastic cos- observers soon find M42, the dramatic Great mic laboratory for astrophysics. Orion Nebula. But an internet sojourn through OrionDeepWide The giant cloud (bottom left) is mostly cold the archives of APOD (Astronomy Picture of Credit & Copyright: Robert Gendler hydrogen and some helium, full of dust and the Day: http://antwrp.gsfc.nasa.gov/apod/ contracting under its own gravity. The stellar archivepix.html) reveals the nebula is much of Orion by Mathew Spinelli hints at the giant nurseries contain glowing gas, hot young stars, larger and more fascinating than what the hu- dusty molecular cloud that spawned Rigel and proplyds, and stellar jets spewing material at man eye can see. In fact, the deep film image the belt stars Alnitak, Alnilam and Mintaka. I high speeds. Many of the filamentary struc- Orion Nebula in Oxygen, Hydrogen, and Sulfur tures visible in this image are actually shock Credit & Copyright: WFI, MPG/ESO 2.2-m Telescope, La Silla, ESO waves - fronts where fast moving material en- counters slow moving gas. Imaging through these filters allows scien- tist to trace the abundances of specific elements. Many organic molecules like water, methane, alcohol, and formaldehyde are being synthe- sized deep within the cloud, shielded from UV radiation, and utilizing the surfaces of carbon and silicate dust grains. These are detected us- ing radio telescopes. Recent observations have confirmed that water molecules now exist in the famous Orion Nebula, and are still form- ing. The nebula is so vast that even the mea- sured minuscule production rate creates enough water to fill Earth’s oceans 60 times every day, speculate discoverers led by M.