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AAVSO Special Notice #216

Two new FU Orionis variables in Cygnus


August 27, 2010: Two new eruptive, pre-main sequence stars of FU Orionis type have recently been discovered in Cygnus.  Observations of both are encouraged to better characterize the behaviors of these two objects.

The first object was an outburst of the star HBC 722 reported by E. Semkov and S. Peneva (Inst. of Astronomy, Sofia, Bulgaria) in ATel #2801 (2010 Aug 17).  The object was reported to have risen by R=3.3 magnitudes over the time span of 2010 May 13 to 2010 August 16. Subsequent spectroscopy reported by U. Munari et al. (ATel #2808, 2010 Aug 23) support this object's classification as an FU Orionis ("FU") star.  Munari et al. reported the object at V=14.04 on 2010 Aug 21.9 UT.

The second object was a new optical source discovered by K. Itagaki (Yamagata, Japan) on 2010 Aug 23.745 (JD 2455432.245) and reported in CBET 2426 (D.W.E. Green, editor).  As noted by H. Yamaoka in CBET 2426,
the object appears faintly near magnitude 20 on a DSS image taken on 1990 Sep 11, but not on other plates.  The confirming optical image (CBET 2426) reported the object at an unfiltered magnitude of "about
13.8".  Subsequent spectroscopy and photometry of this object by U. Munari (CBET 2428) showed that this object also has the characteristics of an FU Ori star.  Munari reported the object at V=14.91 on 2010 Aug 26.83 UT.

The first object has the name "HBC 722"  in AAVSO VSX and the AUID 000-BJW-349.  It is located at the following (J2000) coordinates:

RA 20:58:17.03 , Dec +43:53:43.4

The second object has been assigned the name "VSX J205126.1+440523" in AAVSO VSX and the AUID 000-BJW-353.  It is located at the following (J2000) coordinates:

RA 20:51:26.19 , Dec +44:05:23.6

Neither object currently has assigned comparison stars, so please clearly indicate your comparison and check stars when submitting data.

Please use the names "HBC 722" and "VSX J205126.1+440523" when submitting data to the AAVSO.

This AAVSO Special Notice was prepared by Matthew Templeton.

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