The Denver AUGUST 2017 OBSERVER Cygnus to Hercules Deneb Draco Boötes Zeta (ζ) Dra Cat’s Eye Nebula NGC 6543 Eta (η) Dra Dziban Psi1 Dra Draco Milk y W a Pherkad y Kochab Cepheus Ursa Minor (“Little Dipper”) Polaris Alpha (α) UMi Cassiopeia Ursa Major (“Big Dipper”) MERIDIAN Wide view, looking due north in Denver skies at 10:00 PM in mid-August; center of chart is roughly 50° above the horizon. Note that the orientations for most of the constellations shown are “upside-down” from traditional charts, which are generally drawn assuming a south-facing observer. Object positions, constellation and meridian lines charted in SkySafari, and then enhanced. AUGUST SKIES by Zachary Singer Sky Calendar 7 Full Moon The Solar System should be visible about 8° west of the Sun. At 14 Last-Quarter Moon magnitude 1.8, the red planet will be slightly Briefly: This will be a great month for Sat- 21 New Moon dimmer than Regulus, which itself “should” urn! Look for it in the southwest after dark, 21 Solar Eclipse be visible, a little over 1° from the Sun. Some gleaming above the constellation Scorpius. 29 First-Quarter Moon **This month, the BIG NEWS is thetotal sources have suggested binoculars for view- solar eclipse on the 21st, and I want to put ing this star, but I do not recommend it— across to everyone the necessity for eye-safety folks will be tempted to go filterless on their In the Observer during the eclipse’s partial phases. As of this binoculars and totality will be over sooner writing, DAS still has a small supply of than realized, creating a major risk. Jupiter President’s Message . .2 eclipse glasses—they’re needed at all times will be low on the eastern horizon, and Mer- Society Directory. 2 while viewing the Sun here in Denver, and for cury will be a dim 3.3-mag, 10° east of the all but one or two minutes where totality can Sun. (Its thin crescent is a tempting notion, Schedule of Events . 2 be seen. Supplies of these glasses are becom- but the time to find it will be short, and the DAS News . 3 same safety risks exist.) ing tight through other sources, so come to NASA Space Place . .4 the Observatory while we have them.** Please see this month’s “President’s Mes- About Denver Astronomical Society . 5 During totality, Venus, at mag. -4.0, will sage” for additional information and links be obvious in the twilight sky and Mars about the eclipse. The Observer is available in color PDF format from the DAS Continued on Page 5 website: http://www.denverastro.org/das/denver-observer/ THE DENVER OBSERVER AUGUST 2017 Society Directory PRESIDENT’S MESSAGE by Ron Hranac DAS Executive Board August’s Total Solar Eclipse President: st Ron Hranac The total solar eclipse of Monday, August 21 , web site. (Zoom in to any location on the map, [email protected] 2017, is just about upon us. On that date, the click on that spot, and details about the eclipse Vice President: Moon’s umbral shadow will race from Oregon at that location will pop up.) Here’s a link to Lindsey Shaw https://eclipse2017.nasa.gov/ [email protected] to South Carolina in a mere 94 minutes. The the map page: last total solar eclipse that was visible in the sites/default/files/interactive_map/index.html. Secretary: Jeff Tropeano continental United States happened 38 years There is also a great app written by the same [email protected] ago, and it has been 99 years since a total solar folks who did NASA’s interactive map, called Treasurer: eclipse’s path of totality crossed the U.S. from “Totality” by Big Kid Science, available for free Michael Nowak [email protected] coast to coast similar to this year’s. I think from the respective app stores for both Apple Executive Board Members: it’s safe to say there’s a lot of excitement and and Android platforms. Brent Blake Zach Gilbert anticipation in the air. The “President’s Message” in the June 2017 Julie Candia Ed Scholes Denver Astronomical Society has received Denver Observer (https://www.denverastro.org/ Jack Eastman Sorin Joe Gafford Dan Wray several requests over the past few months ask- newsletters/june2017_denverobserver.pdf) in- Past President, Ron Pearson ing if we are planning eclipse-day observing cludes a discussion about how to observe this President Emeritus, Larry Brooks activities at DU’s Chamberlin Observatory or month’s eclipse. The PowerPoint slides I used Committees other venues in or near Denver. The answer is for a presentation I did on the same topic, Van Nattan-Hansen Scholarship Fund: no, because most of our members are plan- with assistance from fellow DAS member Jeff Tropeano (Chair) ning to travel out-of-state to locations within Sorin, at the July general membership meeting PO Box 100621 Denver, CO. 80250-0621 the path of totality. Those who stay behind in is available at https://www.denverastro.org/das/ EGK Dark Site Committee: the Denver Metro area will get to see a nice wp-content/uploads/2017/07/How-to-observe- Darrell Dodge, Interim Chair partial solar eclipse on the 21st (about 92 per- 2017-total-solar-eclipse2.pdf. [email protected] cent obscuration at maximum), but they won’t Safety IDA Representative: Dr. Robert Stencel experience a total eclipse. For that, one must It has been said that a total solar eclipse is [email protected] be within the relatively narrow path of totality, Mother Nature’s most spectacular sight. But Volunteers or Appointed which averages about 67 miles wide. NASA observing the Sun for any reason requires that Representatives has a helpful interactive eclipse map on their ALCor: safety be the top priority. The Sun is bright Darrell Dodge 303 932-1309 Continued on Page 5 Newsletter Editor: DAS SCHEDULE Zachary Singer 303 718-4188 [email protected] Newsletter Proofreaders: August 2017 Darrell Dodge, Ron Hranac 4 DAS General Meeting—DU’s Olin Hall, Rm. 105—Starts at 7:30 PM Website: Darrell Dodge 11 E-Board Meeting—At DU’s Historic Chamberlin Observatory, 7:30 PM. All members welcome. [email protected] 12 Member In-Reach—At EGK Dark Site & Brooks Observatory, 7:00 PM. (See page 3.) IT Coordinator: 19 Dark Sky Weekend—EGK Dark Site & Brooks Observatory Ken Sturrock [email protected] 26 Open House—DU’s Historic Chamberlin Observatory—Starts at 8:30 PM External Outreach Coordinator: (September 2017) Julie Candia [email protected] 2 Member In-Reach: Roundtables, 7:00-9:00 PM (See page 3.) Public Night Coordinator: 8 DAS General Meeting—DU’s Olin Hall, Rm. 105—Starts at 7:30 PM Hugh Davidson 303 679-0629 15 E-Board Meeting—At DU’s Historic Chamberlin Observatory, 7:30 PM. All members welcome. Librarian: Eileen Barela Telescope Loan Program: During Open House, volunteer members of the DAS Public Nights feature a presentation on astronomical Ed Scholes bring their telescopes to the Chamberlin Observa- subjects and a small-group observing session on the [email protected] tory’s front (south) lawn, so the public can enjoy historic 20-inch telescope (weather permitting), at Cham- views of the stars and planets, try out different berlin Observatory on Tuesday and Thursday evenings DAS Information Line: telescope designs, and get advice from DAS mem- (except holidays), beginning at the following times: (303) 871-5172 bers. The Observatory is open, too (costs listed DAS Correspondence: below), and its historic 20-inch telescope is open March 10 - September 30 at 8:30 PM Denver Astronomical Society for observing with no reservations necessary. October 1 - March 9 at 7:30 PM P.O. Box 102738 Denver, Colorado 80250 Open House costs (non-members): If the skies are clear, Public Night costs (non-members): $4/adult, [email protected] $2/person ($5/family), $1/person in inclement weather. $3/child and students with ID. DAS mem- DU students with ID, and DAS members free. New-Member Ambassador: bers and DU students with ID: free. Digby Kirby Members of the public (non-DAS/DU, as above), please [email protected] make reservations via our website (970) 301-2287 (www .denverastro .org) or call (303) 871-5172. http://www.denverastro.org The Denver Astronomical Society One Mile Nearer the Stars - 2 - THE DENVER OBSERVER AUGUST 2017 DAS NEWS August General Meeting th Volunteer Opportunities On Friday, August 4 , at 7:30 PM, Dr. Jennifer Hoffman will present, “Shadows in Space: What We Learn from Eclipses, Occultations, and Transits.” Saturday, August 5, 2017, TBD: Dr. Hoffman earned her Ph.D. in Astronomy from Jeffco Planetarium, Lakewood. They the University of Wisconsin-Madison in 2002 and are deciding night observing vs. solar held an NSF Astronomy & Astrophysics Postdoctoral viewing. Fellowship at UC Berkeley before joining the DU Sunday, August 6, 2107, 10:00 AM- faculty in 2007. Her observational and computational 4:00 PM: DMNS Free Eclipse Day, research focuses on the connection between super- Denver. DAS table and solar viewing. nova explosions and their massive star progenitors, as Monday, August 7, 2017, 5:30- illuminated by the circumstellar material surrounding 6:30 PM: Eloise May Library, Denver both types of objects. (S. Parker Rd.). Solar observing and Dr. Hoffman also has strong interests in support- eclipse info. ing and retaining women of color and white women Tuesday, August 15, 2017, 6:30- in the physical sciences; she is a co-director of DU 8:00 PM. Belmar Library, Lakewood. SciTech, a summer STEM camp and academic men- Dr. Jennifer L.