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MAST Staff - 2025 Apr 01

New:

  • GFCAT (Million et al. 2023) is the result of a systematic search for intra-visit variability using calibrated GALEX photon events to construct lightcurves at 30-second time resolution.  Using the gPhoton2 software package, a semi-automated search for variable objects was conducted using calibrated photon events from every GALEX visit with at least 500 seconds of exposure time. This is equivalent to searching all visits from the Medium Image Survey ("MIS") or longer exposure lengths.  Source detection was run on the resultant time series of images, and aperture photometry applied in both FUV (where available) and NUV bands using five photometric apertures.  Variable objects were first identified through automated detection and then by-hand screening.  The final product consists of 1959 lightcurves from 1426 unique sources.  The lightcurves are constructed using five aperture sizes (9, 12.5, 17.5, 25, and 35 arcseconds), stored in separate FITS files.  Each GALEX eclipse is analyzed independently, thus, variable objects observed more than once will have more than one set of lightcurves created.  Four catalogs are also provided: an object catalog containing information about the unique objects, a visit catalog containing information about the vetted variable objects in each GALEX visit, an eclipse catalog containing those sources identified as looking like eclipsing objects through visual inspection, and a flare catalog containing those sources identified as looking like flares.

Updated:

  • QLP calibrated light curves from TESS full frame images for Sectors 85-88 are now available at MAST, which add around 4.5 million targets derived from 200 second cadence FFIs.
  • TICA added quick-look, calibrated TESS full frame images from the final portion of Sector 89, and the first portion of Sector 90, and are now available at MAST.
GFCAT figure 6 from Million et al. 2023
GFCAT - (figure 6) An object observed twice by GALEX, about 10 yr apart, in GALEX eclipses 2609 (on the top) and 44383 (on the bottom). It has not been previously described, as far as we know, and demonstrates clear stellar eclipse-like behavior. The second visit to the object captured a full eclipse with a duration of approximately 14.5 minutes, including 1–1.5 minute long entry and exit phases, with a depth of at least two AB mag (the lower limit being consistent with a nondetection). Refer to the capture of Figure 4 for a description of the plot layouts.

 

 

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