A-SETI Garlitz Report 2009.01.17

On 2009.01.17 Joe Garlitz was searching for asteroids and noted in one 60-second frame a "transient star" located at 01:05:16.7 +11:00:02.0 (galactic latitude +3.5 deg).

FOV = 6.0 x 5.7 'arc, north up, east left. Left exposure (03:04:22 UT) shows "transient star" at 01:05:16.68 +11:00:06.2. The right frame was taken immediately afterward, and due to the transient star's saturating 6 pixels in the previous image a "ghost" is present at the same coordinates.

A nearby star has FWHM = 5.7 x 5.7 "arc (EW & NS), and the "transient star" (TS) has FWHM = 2.7 x 2.7 (SE's = 0.1 & 0.2) "arc. The TS appears to be a circular Gaussian (neglecting rows and columns that intersect the 6 saturated pixels) and has a smaller PSF than the 60-second exposure of a nearby star. A very brief & bright flash would produce a smaller PSF. At this observing site it is possible for short exposures to exhibit 2.7 "arc FWHMs.

Therefore, this event remains a possible candidate A-SETI event.

Observatory Info

Joe Garlitz observed with a 12-inch telescope, f/5 and a SBIG ST-402 CCD. The observatory is located at Elgin, Oregon:  observatory link

Explanatory Note:
Gaussian PSFs that are saturated can still have their FWHM measured thanks to a convenient property of 2-dimensional Gaussian functions (having the same FWHM in all orientations): Any slice through the 2-dimensional response function, regardless of offset from the center and regardless of orientation, is a Gaussian having the same FWHM.

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WebMaster: B. Gary.  This site opened:  2013.01.30 Last Update:  2013.01.30