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The Ryerson Astronomical Society (RAS) is the University of Chicago's astronomy club. Our club's purpose is to have all humanity (or all University of Chicago students, for starters) observe the celestial luminaries in hushed awe with our antique 6.25" refractor, 10" reflector, and ~60" radio telescope. Our website has information about upcoming club events; details of RAS history; a collection of astrophotographs and RAS photos; the Rchive, a vast index of RAS documents; useful space and astronomy links; and contact information for our members.

RAS activities Winter Quarter 2013

Monday meetings: We meet to hear astronomy lectures from students and faculty every Monday night at 8 PM in Ryerson 358 (the classroom immediately at the top of the main staircase in Ryerson). Here's the schedule:

April 1Tad Komacek Impact and Radiogenic Heating of Planetsimals in Early Solar System
April 8 Matt Schaffer Ptolemy
April 15
April 22 Will Vaughan Enigmatic Ina-like Lunar feature
April 29
May 6 Prof. Fabrycky Circumbinary planets
May 13 !Elections!
Esteban Zacharzewski

Milky Way
May 20
May 27 Patrick Chen TBD
June 3 Carl Sagan Cosmos

Ryerson Wednesdays: Every clear Wednesday night from 7:30 to 10:00 PM we have public observing at our Ryerson rooftop observatory (all the way up the spiral staircase opposite Ryerson 358).

Special events: We usually spend a night at Yerkes Observatory in Wisconsin every quarter to observe on the 24" and 41" reflectors. In spring quarter we have a Friday evening trip open to the public. Over 40 people went on the 2010 trip! We also occasionally visit dark-sky sites such as Willow Slough in Indiana.

Trouble finding Ryerson? Here's a map of campus showing the location of Ryerson.

Trouble getting into Ryerson? Try entering through Eckhart and crossing over on the second or third floor. If Eckhart's locked, call our office and observatory at (773) 702-7625 (that's 2-7625 from any campus phone).

History of the RAS

The RAS as a student organization at the University of Chicago has existed since 1952 (when our logbooks begin). Read our constitution here. Our observatory has existed at least since 1900, its beginnings lost to history. We operate a 107 year-old 6.25-inch Petitdidier refractor, along with a modern 10-inch (250mm) f/6 Newtonian, both set on a hundred and ten year old Warner & Swasey mount. The mount is painted blue, the same color as the mount of the great Yerkes 40-inch refractor. More history here.

Carl Sagan was president of the RAS in the 1950s. His signature is in our logbooks: Carl Sagan's signature He used to study in the RAS office. Here's another Carl Sagan entry about Chicago temperatures. (This shaky phrase still appears in modern logbooks, especially in the month of January.)

Our 1952-1964 logbook is available here, thanks to John Crocker, who typed in in the entire contents of the logbook. Also available is an RTF version. Here's a guide to John Crocker's markup in the typed logbook.


NGC 2736: The Pencil Nebula 
Image Credit:  ESO
September 24, 2012

Curiosity on Mars: A Wall of Gale Crater
Image Credit: 
August 15, 2012

Curiosity on Mars

Waxing gibbous Moon
February 5, 2009

Mosaic of Moon images from 10-inch reflector

NGC 7635, the Bubble Nebula
November 2008

NGC 7635 imaged with 10-inch reflector

M27, the Dumbbell Nebula
October 4, 2008

M27 imaged with 10-inch reflector

Comet Holmes
October 29th, 2007

Comet Holmes, 36x5s exposures, 0.25m f/6.

Yerkes Observatory aurora
May 15, 2005

Aurora photo by Dean Armstrong

2003 UB313 animation
August 8-9, 2005

RAS member Steven Lucy took these two images of 2003 UB313 at the University of Chicago's Yerkes Observatory using the 41-inch reflector.

More pictures of the May 15, 2005 aurora.
Pictures of the November 8, 2004 aurora.
More CCD images (including supernovae 1998aq!)
First-light images from our old CCD
Photos from a trip to UW-Madison to visit Chris Conselice and the 15-inch refractor and 6-inch Clark owned by S.W. Burnham.

Messier 51 interacting galaxy pair pictures
Old photos of the RAS Observatory and members
Images of Solar System objects
Images of eclipses
Comet Hale-Bopp images
Comet Hyakutake images
Yerkes trip photos

The RChive

Sort through every RAS document and image at the RChive.

Online space and astronomy resources

Contact information

RAS President Champ Taweewat Somboonpanyakul:

Dean W. Armstrong, Observatory Chief: (773) 702-3147 work / (773) 931-9400 cell

2013-2014 Officers:

Vice President

Secretary Paige MacKenzie:


Weather Station Manager Tahoe "Money Bags" Schrader:

Chief Engineer "John Roberts":

Chief Engineer Adam Sutherland:

Chief Engineer Esteban Zacharzewski:

Dome Engineer Jack "Orlowski"-Scherer:

Dome Engineer Michael Cervia

Webmaster Mitch "Ridwan Syed" Spradlin:

Thanks to the University of Chicago Department of Astronomy and Astrophysics for webspace and technical support.