AstroNote 2021-7

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2021-01-06 09:54:06
Type: Announcement-Tool/Utility
Release of the ATLAS Forced Photometry server for public use
Authors: L. Shingles, K. W. Smith, D. R. Young, S. J. Smartt (Queen's University Belfast), J. Tonry, L. Denneau, A. Heinze, H. Weiland, (IfA, University of Hawaii), H. Flewelling (CFHT), B. Stalder (LSST), A. Clocchiatti, F. Förster, G. Pignata (MAS, Chile), A. Rest (STScI), J. Anderson (ESO), C. Stubbs (Harvard), N. Erasmus (SAAO),
Source Group: ATLAS
We announce the public release of the ATLAS forced photometry server, which provides public access to photometric measurements over the full history of ATLAS survey.  

ATLAS is a twin 0.5m telescope system on Haleakala and Mauna Loa which is robotically surveying the sky above declination -50 with a cadence of 2 days (Tonry et al. 2018, PASP,130:064505). Two filters are used, cyan and orange (denoted c and o; all mags quoted are in the AB system). While carrying out the primary mission for Near Earth Objects, we report transients to the IAU Transient Name Server  (Smith et al. 2020, PASP, 132:085002) and measure lightcurves for variable stars and AGN (see Heinze et al. (2018)).  The frequent sky coverage, to o ~ 19.5 makes it treasure trove for time domain science. A full description is on the ATLAS homepage at

We announce the public release of the  ATLAS forced photometry server, which provides public access to photometric measurements over the full history of ATLAS survey.  Users can request forced photometry at any position on the sky either for a single position or a list of positions. Currently that is limited to declinations greater than -50 degrees, but will be all sky when the two new ATLAS units are installed in Chile and South Africa in 2021. 

To access the service, follow the link on the ATLAS homepage :

Forced photometry measurements can be made on either a target image (e.g. for the measurement of flux of a variable star), or on a difference image (e.g. for lightcurve of a transient). Data processing and photometry are described in more detail in Tonry et al. (2018) and Smith et al. (2020). Users should note that this is an experimental service, and carefully read the documentation on the data products on the web pages. While we provide a web form and API, large volume requests are not encouraged without conatcting us directly. 

If you use these data in a publication you should cite Tonry et al. (2018). If you use data for transient time-domain science you should also cite Smith et al. (2020), and if you use it for variable object science, then also cite the first data release paper Heinze et al. (2018).

The Asteroid Terrestrial-impact Last Alert System (ATLAS) project is primarily funded to search for near earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; byproducts of the NEO search include images and catalogs from the survey area. This work was partially funded by Kepler/K2 grant J1944/80NSSC19K0112 and HST GO-15889, and STFC grants ST/T000198/1 and ST/S006109/1. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen's University Belfast, the Space Telescope Science Institute, the South African Astronomical Observatory, and The Millennium Institute of Astrophysics (MAS), Chile.