Peremennye Zvezdy

Article in PDF
"Peremennye Zvezdy",
vol. 10, N 26 (2010)

FG Sge: Increase of IR Brightness in August 2010

O. Taranova, V. Shenavrin
Sternberg Astronomical Institute, Moscow, Russia

ISSN 2221–0474

Received:   26.10.2010;   accepted:   26.10.2010
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Star Name: FG Sge, Hip 099527, IRAS 20097+2010
Coordinates (J2000): 20 11 56.06, +20 20 04.4
Variability type: *;   Limits, System: 6.8 - 12.1 (J);    
Period: Epoch: JD 

We report an increase of the J-band brightness of the unique supergiant FG Sge by the summer of 2010. It follows from our IR observations of the star (1986-2010) that its J-band brightness level in August, 2008 reached an absolute minimum (~12m), and till the beginning of the summer of 2010, the star was almost inaccessible for observations at 1.25 microns. In July, 2010, the star was brighter by approximately 1m in the J band than in the summer of 2008. A month later, by the end of August, 2010, the J-band brightness of the star increased by 1m and was already ~10m. At 3.5-5.5 microns, the brightness fluctuations of FG Sge in 2008-2010 had an amplitude of 0.2m. The figure shows J-filter brightness variations of FG Sge in 1986-2010. The arrow marks the beginning of J-band brightness increase of the star in 2010.

Light Curve
FG Sge: Increase of IR Brightness in August 2010

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