[ASA] Announcing the 2nd AST3-2 telescope data release: i-band images from Antarctica

[Michael Ashley]

Dear all,

It is my pleasure to announce the availability of 221,731 images (totalling ~12 TB of compressed FITS files) obtained with the Chinese AST3-2 telescope during 2017, supported by NCRIS funding through AAL.

AST3-2 is a 0.5m aperture optical telescope at Dome A, Antarctica (80.37S, 77.53E, 4093m altitude). It uses a Semiconductor Technology Associates CCD with 10,560 x 5,280 pixels covering a FOV of 4.3 square degrees at a scale of 1 arcsec/pixel. The telescope has a Sloan i-band filter.

The data are primarily interesting since they are largely unaffected by diurnal aliasing (by virtue of the Antarctic location of the telescope), and will allow quite precise photometry due to low airmass variations, low scintillation noise, and low water vapour absorption.

The source targets include:

  TESS CVZ:     91,064 images covering 32 fields (between 1100 and 4600 images per field)
                                10 sec exposures
  Proxima Cen:  27,373 images   10 sec
  Beta Pic:     68,742          0.1, 0.5, and 0.7 sec
  SN survey:    25,844          60 sec
  LMC:           2,274          60 sec
  IC2391:        2,745          10 sec
  MV Pav:        1,242          30 sec
  miscellaneous  2,447

Raw images are provided, together with pipeline software. The pipeline takes less than 5 seconds per image on a typical desktop computer and includes overscan correction/removal, fixed-pattern noise removal, flat-fielding, photometric calibration to better than 0.1 mag, astrometric calibration to GAIA DR2 (typically 0.05 arcsec residuals per star), and PSF characterisation.

A sample image (a 2.7 MB png file) is available here: https://protect-au.mimecast.com/s/ijybCGvmB5ilLxKmcKTeHj?domain=mcba1.phys.unsw.edu.au. The full FITS file (223 MB) corresponding to this image is here: https://protect-au.mimecast.com/s/J650CJyp0qhzQG3RtGuARB?domain=mcba1.phys.unsw.edu.au. Note that the flat-fielding can be improved.

An sqlite3 database of the FITS headers of the 221,731 images (278 MB) is here: https://protect-au.mimecast.com/s/T9LnCK1qJZtwrgzls3IQBb?domain=mcba1.phys.unsw.edu.au which allows you to easily explore the characteristics of the data release (e.g., RA, Dec coverage, extinction, sky background, FWHM of the PSF, etc). Example SQL queries and plots are given here: https://protect-au.mimecast.com/s/lZVQCL7rK8tOYxyAum4r58?domain=mcba1.phys.unsw.edu.au

If you wish to publish papers using the data you should first engage with the AST3 consortium to check publication rules and to ensure that you aren't conflicting with an existing project.

Projects currently being undertaken with 2017 AST3-2 data include:

 - exoplanet transits
 - supernovae, including spectra taken with WiFeS on the ANU 2.3m
 - observations of Beta Pic
 - pulsating variables and binaries
 - asteroseismology of red giants
 - Proxima Cen B
 - stellar flares
 - characterisation of the seeing at Dome A using precision astrometry (incidentally, we have some very exciting results from a DIMM this year; more details in a publication soon)

To obtain a copy of the raw 2017 data on a 14TB hard disk, please email me. No charge, limit of one disk per institution. There is a Wiki for collaborators to share information about the AST3-2 data and pipeline; please email me if you would like to join. 

Best regards,
Michael Ashley <m.ashley at unsw.edu.au>

P.S. Sorry I will miss the ASA this year, it is during my busy teaching period. I hope that you all have a great time!
-- 
Professor Michael Ashley                   Department of Astrophysics
University of New South Wales       http://www.phys.unsw.edu.au/~mcba