FEBRUARY 2011 FEBRUARY 2011 OT H E D Ebn V E R S E R V E R

THE DENVER OBSERVER FEBRUARY 2011 FEBRUARY 2011 OT h e D eBn v e r S E R V E R

S T E L L A R S P E C T A C L E S Calendar Discovered by William Herschel on January 18, 1784, the Christmas Tree Star Cluster (NGC 2264), is a 2...... New moon huge star-forming region more than 2,600 light years from Earth in the winter constellation Monoceros. Herschel discovered the associated nebulosity the next year. Two distinctive nebulae—the Cone and Fox 11...... First quarter moon Fur—are within the nebular cloud of ionized hydrogen, which is being blown away by the giant 5th magni- tude star S Monocerotis that forms the base of the Christmas tree. The blue reflection nebula surrounding 18...... Full moon S Mon, the tiny Snowflake Cluster above the cone and a rare yellow nebula in the center of the tree are only visible in photographic images or very large scopes. Taken Dec. 6, 2010 at the EGK Dark Site, Darrell 24...... Last quarter moon used a modified Canon 450D through an AT8IN f/4.8-inch imaging Newtonian. Image © Darrell Dodge Inside the Observer FEBRUARY SKIES by Dennis Cochran UGE GAMMA RAY BLOB IN SPACE!” A Auriga is overhead, which means ε (epsilon) Aurigae President’s Corner...... 2 “Hmember of the Cosmology Discussion Group is, as well. This binary system-with-disk should be com- at Boulder Library sent this NASA info out to ing out of its eclipsed state, which was at its dimmest Society Directory...... 2 the members. The blob is actually two blobs above and last August. ε (epsilon) Aurigae is the star southwest of below the poles of our galaxy that emit x-rays. They Schedule of Events...... 2 the bright alpha star Capella, at the point of a sharp were discovered by the Fermi Spacecraft’s Large-Area little triangle that adorns the west side of the Chario- D-Files Article...... 4 Telescope. A previously-unknown aspect of the Milky teer. The recovery light curve of this eclipsing system Way, this structure stretches across the sky from Virgo may be smooth or may be fluctuating, depending on Help Wanted...... 5 to the southern constellation, Grus. Each blob is a sort the character of the disk that surrounds the giant F- of bubble with well-defined edges. Its nature and origin type star and embeds the smaller B-type star, and also NASA’s Space Place...... 6 are not understood, but one immediately suspects that on whether the giant star pulsates, as these stars often the central black hole of our galaxy may have some- do. Somebody gets to untangle all of this by recording DAS Annual Spring Banquet...... 6 thing to do with it, or was perhaps a starburst in the and studying the spectrum of Epsilon, but it may be past. I shouldn’t have even mentioned this since it is New Astronomer’s Den Chart...... 7 possible for amateurs to plot its information-laden not something we can observe, but it’s nice to light curve by observing the star every night and esti- “Pac-Man” Nebula Photo.... back page know about. There is always more to be discovered in mating its brightness (apparent luminosity) in compari- the universe. Continued on Page 3 The Denver Astronomical Society One Mile Nearer the Stars Page 1 THE DENVER OBSERVER FEBRUARY 2011 PRESIDENT’S CORNER by Ron Pearson or members of the DAS, February is the most more communication with other officers, committee Society Directory F important month in our calendar as an folks, members and the public. President: organization of people that come together We have far more opportunities and technology Ron Pearson (303) 670-1299 regularly to enjoy astronomy and related activities. for communication now than ever before—the [email protected] You could look through a telescope all by yourself, major pipeline, now, being the internet. Therefore if Vice President: but hey, you decided to seek out and share your you decide to serve DAS with your time and talents Norm Rosling (303) 252-1214 [email protected] endeavor with about 299 other people in the on the E-Board or in other activities such as Secretary: immediate area. As an organization dedicated to committees, the most important requirement of Bonnie Kais (720) 344-4263 sharing astronomy, it is when you, the members, doing the job well is communication with others Treasurer: decide how we are going to best achieve our goal. that share responsibility. If you are one of those that Brad Gilman (720) 488-1028 Members have input all year round and like to get things done and not just think about opportunities to participate in many activities, them or gripe about problems, the most effective Executive Board Members either as individuals that just use the dark site, or as way to get support and help from others is to work Jack Eastman Tim Pimentel full participants that at getting your ideas across through communication. Joe Gafford David Shouldice contribute their time and The key to being an active member who is Frank Mancini Steve Solon talents to all of us. informed of Keith Pool Dan Wray Ron Mickle, Past President February is when we have the latest President Emeritus, Larry Brooks our “Annual Meeting” things in the which includes a short sky, finding out Committees business report on the if folks are Van Nattan-Hansen Scholarship Fund: financial status of our going to the Ron Pearson (Chair) organization. We also hold dark sky site or P.O. Box 150743 elections for officers and just what is Lakewood, Colorado 80215-0743 EGK Dark Site Committee: Executive Board members. You get to decide who happening the Darrell Dodge, Interim Chair will best serve and work toward the goals of the next meeting, Email: [email protected] DAS organization, both through the nomination is joining the IDA Representative: process and the election. It might even be you. As DAS Yahoo Dr. Robert Stencel Email: [email protected] someone who has served as an officer or board group. It might Student Astronomy Chair: member on and off for 20 some years, and as mean getting Naomi Pequette (Chair) President for one year, the one thing, yes, that “One your Observer Finance Committee Thing,” that does more to move DAS toward being via the internet Frank Mancini (303) 663-5263 an ever better “club” is good communication. With instead of a several disparate aspects of DAS functions spread week or two Volunteers or Appointed over a large geographic area and activities constantly late by paper. Representatives changing through the year, coordination requires far Continued on Page 3 ALCor: Darrell Dodge (303) 932-1309 Newsletter: Editor: Patti Kurtz (720) 217-5707 Email: [email protected] DAS SCHEDULE Proofing, writing, patience and New Astronomers Den charts: Steve Solon FEBRUARY MARCH The Observer is available in color PDF format from the DAS website. Website: 4-5 EGK Dark Sky weekend 4-5 EGK Dark Sky weekend (Messier Darrell Dodge 12 Open House at Chamberlin (Begins at Marathon weekend!) Email: [email protected] 5:30 P.M.) 12 Open House at Chamberlin (Begins at Chad Warwick, IT Specialist 18 Annual meeting at D.U.’s Olin Hall 6:00 P.M.) Librarian: Phil Klos (Begins at 7:30 P.M.) Election of offi- 19 DAS Spring Banquet and Inauguration DAS Information Line:(303) 871-5172 cers. of Officers (Takes the place of the DAS Correspondence: 25 E-Board Meeting at Chamberlin (Be- General Membership meeting(Begins Denver Astronomical Society gins at 7:30 P.M.) New officers and E- at 6:00 P.M.). Chamberlin Observatory c/o Ron Pearson 2930 East Warren Avenue Board members should attend this tran- 25 E-Board Meeting at Chamberlin (Be- Denver, Colorado 80210 sition meeting. gins at 7:30 P.M.) The Executive Board conducts the business of the DAS at 7:30 p.m. at Chamberlin Observatory. Please see the Schedule of Events for meeting dates. A members are welcome. Public nights are held at Chamberlin Observatory every Tuesday and Thursday evenings beginning at the foowing times: March 9 - April 14 at 8:00 p.m. April 15 - September 1 at 8:30 p.m. September 2 - March 8 at 7:00 p.m www.denverastro.org Costs to non-members are: $3.00 adults, $2.00 children Please make reservations via our website (www.denverastro.org) or ca (303) 871-5172.

The Denver Astronomical Society One Mile Nearer the Stars Page 2 THE DENVER OBSERVER FEBRUARY 2011

FEBRUARY SKIES (CONTINUED FROM PAGE 1) son to nearby stars. AAVSO probably has a chart of can see the Hydra the region with star magnitudes on it. Our own Dr. head and also the bot- Bob Stencel has written about this object. tom of Canis Major be- South of Auriga, Orion is now very well placed low Sirius, the brightest for evening observation. The M42 & 43 complex in star in our night Orion’s sword is the main attraction, enclosing the sky (down-left from four-star “Trapezium” at its core, an intense, beauti- Orion), then you can ful stellar neighborhood that always intrigues the search 1/3 of the way over visual and imaging viewer. Up at the belt of Orion, from Hydra to Canis the hard-to-see “Horsehead” dangles down from the Major for lonely star left-hand star, Alnitak. This small cloud formation in cluster M48. Another space is the other “horse” in the sky, after Pegasus. third of the way gets you Reflection nebula M78 is distanced about one to the cluster pair M46 & belt-width upper left from the belt, next to (part 47. Directly below of?) Barnard’s Loop, a largely-invisible photographic this pair is the even object, almost as big as Orion itself. From there lonelier cluster, M93, to keep on going upper-left from the belt until you’re the left of the Big Dog’s in the region left of Betelguese but down a bit, on hind legs. However you’ll an extension of the line from λ (lamda) Orionis to be lucky to see this low GLITTERING DIAMONDS . . . WITH A HIDDEN SURPRISE λ to the horizon. At the B’juice; (lamda) is the star above the hourglass Although they're technically in the southern constellation Puppis, Messier λ M46-47 level, sweep west shape of the Hunter. Down this line, 1.5 times the 46 (upper left) and 47 vault high enough for northern folk to appreciate to a point under Sirius to (lamda)-B’juice distance, you’ll find the one-degree- them. M46 comes with an added bonus, planetary nebula NGC 2438, the find cluster M41. Now, wide Rosette nebula (NGC 2237) surrounding small hazy sphere in its upper quadrant. The farther of the two, M46 resides from Sirius you can go easier-to-see star cluster NGC 2244, the object to 5,400 light years away, while 47, with its ~50 stars, sparkles from 1,700 light upper-left towards Pro- look for before you try to resolve the Rosette. years distance. Details: image from a scanned negative—Minolta 135mm cyon in Canis Minor. At Cancer is the dim constellation between Leo and lens piggybacked on a CG-11, one-hour exposure on Kodak Royal Gold 40 percent of that dis- Gemini. M44, the Beehive Cluster is just above- film 400, Kiowa Observatory, 1998. Image © Steve Solon right of the delta star in the center of that three- tance you’ll find the M50 armed constellation. δ (delta) Cancri is right on the cluster. Back at Sirius than likely plotting to take over the solar system ecliptic, but of course you can’t see the ecliptic. (You again, the constellation west of it is Lepus the Hare, from Jupiter. can trace it westward, however, from Cancer past right under Orion. And under Lepus, in the line of On the other side of the zenith southwest of the bottom star of the right-hand twin in Gemini, its alpha star to its beta, is globular cluster M79. At Polaris is the Winter Triangle (one that I just made then on to a point below the Pleiades.) You can last a glob, after all those open clusters! up) of the Double Cluster on the southeast side of follow the southeastern arm (leg, actually) of Cancer Planets: Jupiter is still observable after sundown. Cassiopeia’s ‘W’ shape, then the M52 cluster on her down towards α (alpha) Cancri to find, just to its Uranus is loyal to Jupiter, just west of him on the northwest side, and M31 the Andromeda Galaxy west, cluster M67. South of that is the little five- ecliptic. Saturn rises right in the middle of Virgo, in making a nice even triangle with those two on sided head of Hydra the Water Snake. Now, if you the 11-12 P.M. slot, and earlier as the month pro- Cass’s southwest side. gresses. Mars is behind the Sun with Neptune, more PRESIDENT’S CORNER (CONTINUED FROM PAGE 2) If you decide to serve as an officer or on the E-Board, the path to the likely miss out on something, leading to frustration or isolation. As the most information and exchange of information between board meetings is current president, I, and presidents of the past few years, rely on these joining in the DAS E-Board Yahoogroup. We have regular communication pipelines not just to get the latest on a supernova in some galaxy, but about what’s going on, current problems that crop up that need immediate discuss the whole universe of DAS activities so when members come to solving or opportunities that may present themselves with a short fuse that Board meetings, they are informed and prepared to vote on actions or seize require discussion and decisions quickly. Individual e-mail addresses or opportunities if needed. I realize it’s not for everyone, but I hope it appeals voice-mails are too ephemeral for “real-time” information sharing. If you to enough of you to keep making the Denver Astronomical Society one of are not part of these pipelines of communication in the DAS, you will the most vibrant and fun astronomical societies in the United States. ABOUT THE DAS Membership in the Denver Astronomical night of viewing, a tradition the DAS has helped The DAS is 501 (c)(3) tax-exampt corporation Society is open to anyone wishing to join. The maintain since its founding in 1952. and has established three tax-deductible funds: DAS provides trained volunteers who host edu- The DAS is a long-time member in good the Van Nattan-Hansen Scholarship Fund, the cational and public outreach events at the Uni- standing of the Astronomical League and the DAS-General Fund and the Edmund G. Kline versity of Denver’s His- International Dark Sky Association. The Dark Site Fund. To contribute, please see the toric Chamberlin Ob- DAS’ mission is to provide its members a forum bottom of the membership form for details servatory, which the DAS for increasing and sharing their knowledge of (found on the DAS website: thedas.org). helped place on the Na- astronomy, to promote astronomical education More information about the DAS, its activi- tional Register of Historic to the public, and to preserve Historic Cham- ties and the special tax-deductible funds is avail- Places. First light at Cham- berlin Observatory and its telescope in coopera- able on the DAS website at www.denverastro.org. berlin in 1894 was a public tion with the University of Denver.

The Denver Astronomical Society One Mile Nearer the Stars Page 3 THE DENVER OBSERVER FEBRUARY 2011 D-FILES MY SIMPLE ALUMINUM DOBSONIAN TELESCOPE (OR WHAT TO DO WHEN AN AMATEUR ASTRONOMER RETIRES) Article and photos by David Shouldice

he problem with dling to track a T astronomy and aging planet, but that is is that the desire for another story. more and better views If you are inter- collides with my ability to ested in amateur manhandle a telescope. I telescope-making wanted a bigger scope, and (ATM), here is how when the sky is gorgeous I did it: and the seeing is good, I I started, as just wanted to sit and many of you would, watch the moon and plan- at Home Depot. ets and tour the dark skies They had a sur- for nebulae and galaxies—I veyor’s tripod that didn’t want to haul 100 lbs. was just the right over to a field or bench length for my mir- Telescope collapsed for press it into my car. I didn’t ror’s focal length transport. want to take 20 minutes and my desired setting it up or wait a half collapsible trusses. Scope ready for hour for it to cool down The legs conveniently attached to the bottom of the three mirror cell’s viewing. and I didn’t want to buy a mounting screws. van to haul it in. To sim- The secondary cage was somewhat straight forward. I bolted a 14-inch plify my dilemma, the tele- aluminum “Lazy Susan” and a strip of rolled aluminum with right angle scope needed to be portable, quick to set up, cheap and, oh yes, I wanted it brackets to attach the top of the tripod legs. This allowed me to attach the to track the stars. Sadly I have no machine shop at my disposal but, and spider to the rolled ring, and make a simple right angle bracket for the fo- there is a big but (no pun intended), I had more time than money. cuser. This ended up making a surprisingly rigid secondary cage. With all those requirements, I first concluded that I needed to have a The problem now was constructing and rigidly attaching an altitude bear- scope that could survive being left out in the weather. That solves the prob- ing to the bottom. These bearings rotate at the center of gravity of the tube lem of the half hour cool down time and gets it out of the family room when and allow the scope to pivot from horizontal to vertical. If I figured it right, my wife is tired of looking at it. That excluded wood, and left aluminum. my balance point was 16-inch from the bottom of the mirror. If I made the Next, I had to figure out how to make the optical path collapsible and bearing’s radius small, I needed a rigid 16-inch high base to support it. If I strong. The common triangular truss tube structures used on Dobsonian made a big 16-inch radius bearing, the base is small and easy to make rigid, telescopes are very light and strong but do not collapse and require assem- but the bearing gets much larger. I went with a larger radius. I made it from bly and disassembly. a piece of square 1-inch aluminum tubing rolled to a 12-inch radius. (Both I chose an aluminum surveyor’s tripod from Home Depot for the optical this and the rolled ring were made by a sheet metal company in town). The tube. The tripod legs conveniently extended close enough to my 60-inch trick was attaching it to the three legs. I took another piece of 1½-inch focal length. aluminum strip. I attached it from the bottom of the surveyor’s tripod legs I should explain at this point that I had a starting place for the design. In (and mirror cell) using a U-shape giving two parallel sides, which would give its previous incarnation, I had the lovely 12.5-inch mirror in a 14-inch fiber- a place to connect the attachment plate for my altitude bearings. Adding glass tube on a Losmandy G11 German equatorial (read “really heavy”) some aluminum cross braces for stiffness, and attaching the top of the alti- mount. It was a monster. The optical tube had exceeded the 60-lb. weight tude bearings to the side tubes was all it took to make a lightweight but rating of the mount (the G11 itself weighed 75 lbs.) and it would stop run- rigid assembly. ning when it got too cold. So I started with a great mirror, mirror cell, sec- Next, I needed a rocker ondary and spider. box assembly for all this to The secondary cage. What I created is a lightweight, 50 lb., very portable, collapsible (fits in sit on. Following guidance the back of my car), easy-to-collimate 12.5-inch mirror telescope that can be from Dave Kriege’s book, left out in the weather. Its length can be easily adjusted for my bino-viewer The Dobsonian Telescope, I or my webcam, but it is mostly a fast-to-transport (with my added clip-on made four angled supports wheels), easy to set up, reasonable aperture, cheap aluminum telescope. It for the altitude bearings has no wood to worry about warping in the heat or cracking or delaminat- (Teflon-covered) that sat on ing. Needless to say, it’s durable. a square base made of 1- I also added an aluminum equatorial tracking table to allow me to do high inch square tubing. I power planetary work or photography. The tracking table also has the ability braced the corners with to allow the public to view a high power object without my constant did-

The Denver Astronomical Society One Mile Nearer the Stars Page 4 THE DENVER OBSERVER FEBRUARY 2011

The base and sheet metal plates and used Finally I added an aluminum “U” channel to the back of the rocker box mirror box. rivets to attach the plates to with clips to hold in the axle with wheels for easy lugging. I also added some the tubing. For added struc- keepers to hold the mirror box and optical tube together when transport- ture, I attached a “Lazy ing. Susan” ring below the square I have been finessing some of the design to make it stiff enough to han- base and covered it with dle a wind, and have been read- Formica to give a smooth justing the balance point now The telescope rigid surface for the azimuth that all the parts are in place. uncovered. bearing. The scope is quite nice and port- The rocker box assembly able and very easy to transport. It rotates about the ground is just what this aging astrono- board and is supported by mer had desired. three Teflon pads above the Sometime later I will tell you feet. It, like the altitude how I made the aluminum equa- bearings, are covered by torial table that it sits on. Kriege’s recommended Wil- I get many compliments from sonart “Ebony star” lami- the people and families that get nate material. The two to look through my scope at pieces are bolted together to public star parties. When people allow it to rotate about the ask me the brand name of the center. scope I tell them in astronomy, In the past I would have unlike most hobbies, you can made all the base parts from ¾ inch laminated plywood, but now I used 1- build your own equipment from inch square aluminum tubing corner braces and rivets. scratch. Now, that description was only several paragraphs long but it took me I had it out on my driveway more than a year of staring at the half completed design and searching the for Halloween to show off the web to see how others solved the same challenges. stars to the neighborhood kids For the finessing and completion, I added a shroud made of Ripstop and their parents. It is such a nylon that sits on the inside of the tripod tube that is held erect in a column pleasure to use since it is so easy by three rings. I stole these from a collapsible clothes hamper (Don’t tell my and fast to set up for viewing. wife). I Velcro’d it to the secondary cage, and to the mirror cell. Also, there When done and I am tired, I is a separate Ripstop nylon secondary cover to block stray light from get- collapse the scope, cover it, clip ting to the back of the focuser. on the wheel bar, bring it in and then collapse myself. HELP WANTED—DAS by Ron Pearson ith the DAS elections coming up at the Public Night Team Lead: Lead coordinator distribution of both paper and PDF version W February meeting, I want to make a request for Chamberlin Public Night teams. Coordinates through “Constant Contact” or the DAS website. of you, the membership, to offer us your and communicates with team leads for training, VanNattan-Hansen Scholarship Fund: time and talents, not just by running for an Officer certifications and assignments, coordinates to fill-in Oversees scholarship fund and selection of awar- or Executive Board position, but as a non-elected when there are absences on teams; works closely dees. Chair (currently myself) and committee volunteer. While the E-Board members give of with the observatory Director and staff. The cur- member positions are all way past due to be their time, there are several non-elected volunteer rent lead is Ron Mickle, who is overbooked with changed according to VN-H bylaws. roles where many tasks are performed by the few two teaching jobs and full-time day job. ALCOR: Astronomical League Correspondent. that keep the DAS running day to day. One could Dark Sky Site Committee Chair: Heads up Keeps membership list in national A.L. current, say it’s not fair that only a couple dedicated indi- dark site committee, oversees budget of dark site, promotes A.L., certifies Observing club partici- viduals give so much of their time, but it also puts construction, operation, maintenance of facilities, pants, promotes meetings and information. Current the DAS in a precarious position; if one key person site orientation of new members, any issues related ALCOR is Darrell Dodge. can’t carry out that function anymore, the things to land-owner/lease, upcoming issue to resolve of DAS Website: The website is the public face of many take for granted will not happen, which will continuing dark site location or new site. Darrell the DAS, and therefore very important. The cur- make many members unhappy. As you’ll see from Dodge is current “acting” head, and has been for rent Webmaster is Darrell Dodge. Close coordina- my summary, some individuals carry out multiple the past 2-3 years. tion and communication is needed with calendar of tasks and could use a break. Here are some of the Observer Newsletter: Editor and proof- events and officers. important, non-elected functions or roles that are reading are managed by Patti Kurtz and Steve So- I hope this gives you a partial picture of the im- often taken for granted, but require a willing, lon. Distribution and newsletter pickup from the portance these positions take in your enjoyment of knowledgeable person to carry out: printer roles are shared by three to four individuals, the Denver Astronomical Society. Under each of Membership: Taking in and accounting for including Darrell Dodge, who have been in these these lead roles are, of course, the volunteers who memberships; folks joining and leaving, annual roles for a number of years. Coordination is closely contribute to each function. Even if you don’t step- roster and data base; currently handled by Darrell tied to membership coordination duties to keep the up to the plate for one of these roles, it is important Dodge and Brad Gilman, DAS Treasurer. mailing list current and accurate while handling that they, the individuals and the time they give to you, not be taken for granted.

The Denver Astronomical Society One Mile Nearer the Stars Page 5 THE DENVER OBSERVER FEBRUARY 2011 NASA’S SPACE PLACE PLANETS IN STRANGE PLACES A Space Place Partner Article by Trudy E. Bell HUMONGOUS! Keep up with the Artist’s rendering com- latest findings from pares size of a hypo- the Spitzer at thetical hypergiant star www.spitzer.caltech.edu. and its surrounding Kids and their dusty disk to that of our grownup friends can solar system. enjoy beautiful images Courtesy NASA/JPL from Spitzer while playing Spitzer Con- centration at The Space Place (spaceplace.nasa.gov/en/kids/spitzer/concentration). This article was provided by the Jet Propulsion Labo- ratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

DAS Spring Banquet

Saturday, March 19th, 6-9 P.M. Columbine UU Church, Littleton

Mexican Buffet by Angies of Littleton Cerveza ed star, blue star, big star, small star—planets disks of what might be planet-forming dust and may form around virtually any type or size of even sand. Rstar throughout the universe, not just around At the other extreme is a tiny brown dwarf star Cost: $15 per person mid-sized middle-aged yellow stars like the Sun. called Cha 110913-773444, relatively nearby (500 That’s the surprising implication of two discoveries light-years) in the Milky Way. One of the smallest in 2006 from the 0.85-meter-diameter Spitzer brown dwarfs known, it has less than 1 percent the Installation of Ofﬁcers, Space Telescope, which is exploring the universe mass of the Sun. It’s not even massive enough to Presentation by: from orbit at infrared (heat) wavelengths blocked kindle thermonuclear reactions for fusing hydrogen Naomi Pequette by the Earth’s atmosphere. into helium. Yet this miniature “failed star,” as At one extreme are two blazing, blue “hypergiant” brown dwarfs are often called, is also surrounded stars 180,000 light-years away in the Large Magel- by a flat disk of dust that may eventually clump into Registration form lanic Cloud, one of the two companion galaxies to planets. (This brown dwarf discovery was made by a our Milky Way. The stars, called R 66 and R 126, are group led by Kevin Luhman of Pennsylvania State online soon at: respectively 30 and 70 times the mass of the Sun, University.) www.denverastro.org/banquet “about as massive as stars can get,” said Joel Kastner, Although actual planets have not been detected 2011.html professor of imaging science at the Rochester Insti- (in part because of the stars’ great distances), the tute of Technology in New York. R 126 is so luminous spectra of the hypergiants show that their dust is that if it were placed 10 parsecs (32.6 light-years) composed of forsterite, olivine, aromatic hydrocar- away—a distance at which the Sun would be one of bons, and other geological substances found on WELCOME the dimmest stars visible in the sky—the hypergiant Earth. DAS NEW MEMBERS would be as bright as the full moon, “definitely a These newfound disks represent “extremes of daytime object,” Kastner remarked. the environments in which planets might form,” Erica Calog Such hot stars have fierce solar winds, so Kastner Kastner said. “Not what you’d expect if you think Jeff Calog and his team are mystified why any dust in the our solar system is the rule.” Gil Davis neighborhood hasn’t long since been blown away. Hypergiants and dwarfs? The Milky Way could But there it is: an unmistakable spectral signature be crowded with worlds circling every kind of star Craig Henderson that both hypergiants are surrounded by mammoth imaginable—very strange, indeed. Jon Jouett Thomas R. Leet

The Denver Astronomical Society One Mile Nearer the Stars Page 6 THE DENVER OBSERVER FEBRUARY 2011

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The Denver Astronomical Society One Mile Nearer the Stars Page 7 THE DENVER Observer FEBRUARY 2011

NGC 281 The Pac-Man Nebula In Cassio- peia was taken in November at the DSS. This is a mosaic of six frames done with the ST-2000XM CCD camera on Joe’s 18-inch Newtonian. He made 20 minute exposures each of HaLRGB ﬁl- tered ﬁve minute subs on each frame.

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