[IAUC] CBET 2647: 20110203 : V1647 ORIONIS

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                                                  Electronic Telegram No. 2647
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau en eps.harvard.edu (alternate cbat en iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


V1647 ORIONIS
     V. Venkat and B. G. Anandarao, Astronomy and Astrophysics Division,
Physical Research Laboratory (PRL), Ahmedabad, report follow-up near-infrared
observations on the eruptive young stellar object V1647 Ori (= IRAS 05436-0007;
cf. IAUCs 8284, 8289; Reipurth and Aspin, 2004, Ap.J. 606, L119; Ojha et al.
2006, MNRAS 368, 825) done using the PRL 1.2-m telescope at Mt. Abu.  The new
observations show that there was no significant change in the infrared
photometric magnitudes reported earlier in the 2008 outburst phase (IAUCs 8968,
8969; CBET 1596; IAUC 9006; CBET 2104; Aspin et al. 2009, Ap.J. 692, L67),
yielding J = 10.76 +/- 0.123; H = 9.02 +/- 0.227; K = 7.51 +/- 0.225 (average
of 15 sets of observations spanning the period Nov. 2008 to Jan. 2011 with the
standard deviations given).  The object remained stable within one sigma in
all the bands.  However, on one occasion (2010 Nov. 7), the object brightened
in the J band by more than 3 sigma (10.36 mag); on another occasion (2010 Dec.
19), it became fainter in the H band by more than 3 sigma (9.77 mag) when
compared to the average values over this period.  Spectra taken on a few
occasions showed variations (concerning features such as the Brackett-series
lines or CO bands) on a day-scale -- possibly due to accretion-rate variations
(e.g., Brittain et al. 2010, Ap.J. 708, 109).  Monitoring observations will be
continued in the coming months.


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                         (C) Copyright 2011 CBAT
2011 February 3                  (CBET 2647)              Daniel W. E. Green