The Amateur Sky Survey Project

Glenn Gombert
Miami Valley Astronomical Society
Dayton, Ohio

A presentation for the 109'th meeting of the Astronomical Society of the Pacific, held in Chicago, IL
transliterated from Powerpoint to HTML by Michael Richmond, June 19, 1997

You may prefer a GIF version of the presentation. Glenn has written a short report after the meeting.

What is the Amateur Sky Survey ?
The Amateur Sky Survey (TASS) is a group of amateurs (and several professionals) who are building a set of CCD drift scan cameras, and writing the associated data reduction software which will be used to monitor a wide angle strip of the sky.

The TASS Project Objective:
TASS is an Astronomical "Survey" Project whose purpose is to record a wide-strip of sky on a regular basis from multiple sites. Previous large scale astronomical survey projects: Palomar Sky Survey's I & II. Modern day astronomical survey projects include MACHO and OGLE.

Characteristics of a "Sky Survey"
Typically records a large area of the sky at any one time. Palomar Sky Survey's photographed a 6 degree field down to 21st magnitude. MACHO and OGLE Surveys perform millions of photometric measurements per night searching for "Micro-Lensing" events.

Objectives of the TASS Project:
Image a 3 degree area of the sky, centered about 0 degrees Declination from multiple sites. Perform stellar measurements in several different photometric bands Develop automated software techniques of data reduction. Share results over the Internet.

List of TASS participants:

Current TASS Camera Locations:

TASS "Mark III Camera" Overview:
Each camera element uses a Kodak KAF-0400 chip and 135 mm camera lens . Three camera elements are combined to form a "triplet" . The middle camera is pointed due South with the other two cameras offset by +/- 15 degrees (1 hour) in RA.

TASS "Mark III Camera" Overview(cont.):
The middle camera uses a photometric " V" band filter, end cameras uses "I" band filters. Image scale "on-chip" is 13.8 arcseconds/pixel Each camera acquires data continuously in "drift-scan" or TDI mode. Equivalent exposure is 492 seconds.

Characteristics of TASS Mark III Camera:
Each camera records a 3 degree wide "strip" of sky all night long (barring clouds). Average amount of data collected (per clear night) is 150 megabytes. Five TASS site have collected data on a regular basis. Limiting magnitude ~14.5 "V" Band, ~13.4 "I" Band.

TASS Image File Format:
TASS images written to disk in 16 bit integer FITS format. Beginning RA for each image is calculated from local time. Each image file is 800 x 896 (1.42 megabytes) FITS image header can be customized as necessary to fit the needs of each installation.

TASS Software:
Real-time DOS control program that is used to acquire images from a TASS triplet. Various types of image processing software are presently used to reduce TASS images to calibrated "lists" (catalogs) of astronomical objects. Astronomical "catalogs" are the final product from TASS image processing.

Current TASS Project:
Image three different fields on regular basis: Combining the results from different sites with results presented at June AAS meeting

June AAS Meeting featured a joint "Professional/Amateur"session
Leif J. Robinson (Sky & Telescope) and Laurence A. Marschall (Gettysburg College) organized a one-day session of oral and poster presentations by professionals and amateurs as part of the 190th meeting of the American Astronomical Society The aim is to showcase joint projects that have already yielded results and to identify possibilities for future one-on-one collaborations between amateurs and professionals. Tom Droege, Michael Richmond and Glenn Gombert presented papers on various aspects of the TASS Project.

Arne Henden at the US Naval Observatory has used his FAAST telescope to produce photometeic standards for the A,B, & C TASS fields Henden has also written a suite of programs to take TASS catalogs generated at various sites to one composite set of measurements.

USNO FASTT Standard Fields:
These standards are in three 11x11arcmin regions in SMSP-B They range in brightness from V=8.6 to V=17, and so should be good to use in determining faintness limits on the TASS frames. The astrometry is good to about +-0.1 arcsec; the photometry is typically 0.01mag accuracy, using a 12arcsec aperture. They were determined on the basis of three consecutive photometric nights on the 1.0m FASTT-USNO telescope.

Analysis Of TASS A/B/C "SMSP" Fields:
"Collate" the results of each nights "calibrated" star-lists into one file which contains at least two photometric measurements of each star ("V" & "I" band) "Transform" collated star-lists into standard photometric magnitudes. Create a "master-list" of all photometric measurements from each of the TASS cameras star-lists for a given Field (A/B/C) Create a "master-list" of differential magnitudes that did not have photomertic conditions (based on 10 near-by stars) Create list of candidate variables for each field

The Amateur Sky Syrvey
Candidate Variable Stars Form SMSP -"A" Field 
    Star ID     RA         Dec      quality     notes
        271    186.7608   -0.6216    fair       GSC 4941:395
        518    187.7910   -2.0670    fair       SAO 132882       
        699    188.5854   -1.1772    good       BP Vir; GSC 4948:401
        726    188.6651   -0.6326    fair       GSC 4948:57      
       1100    190.2649   -0.6204    good       MG found; SAA 138910; K5
       1127    190.3701   -1.7066    fair       GSC 4949:843
       1328    191.2854   -0.4616    fair       GSC 4949:1092
       1333    191.3202   -0.2781    good

Future Plans:
Continue to acquire and reduce data from TASS Mark III camera sites Mark IV TASS camera is under development (will image 35 square degrees of sky ) NSF Proposal has been written to establish an international photometric database at Princeton University in collaboration with mico-lensing surveys accessed via the Internet

Closing quote from Dr. Bohdan Paczynski
"The Amateur Sky Survey is a new phenomenon, the beginning of a new epoch. These "amateurs" use modern technology: CCD detectors for data acquisition, powerful computers for data processing, and the Internet for communication. For many years I was dreaming about developing a similar system. The success of microlensing searches made me think this it should be possible to monitor brightness of millions of stars over the whole sky every night. When I "discovered" TASS almost two years ago I realized that the task is not only feasible, but that the project is already under development. I am currently planning, in an informal collaboration with TASS and my colleges at the Warsaw University Observatory, a development of a database of photometric measurements that would be readily available over Internet. The Amateur Sky Survey Closing quote from Dr. Bohdan Paczynski One may envision discoveries of new variable objects to be done not by an observer looking through a telescope, but by anybody with Internet access browsing through the database. The volume of data streaming out of microlensing searches, and soon to stream out of numerous TASS cameras is so immense that there is no way a single person, or even a single group can cope with the data flow. When technology matures the individual observations may turn out to be "too cheap to meter", and the bottleneck will not be related to the telescopes or CCD cameras, but to human brainpower available for data analysis. I is very exciting that "amateurs" are leading in this new development. the immense volume of data and finding new variables, new types of objects..

Internet Sites of Interest:

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