[IAUC] IAUC 9046: 2002 XH_91; V1280 Sco [25139-2009/08-R1]

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                                                  Circular No. 9046
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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2002 XH_91
     K. S. Noll, Space Telescope Science Institute (STSI); W. M.
Grundy, Lowell Observatory; S. D. Benecchi and E. A. Barker, STSI;
and H. A. Levison, Southwest Research Institute, report that images
taken during 2008 Nov. 8.9381-8.9700 UT with the Wide Field
Planetary Camera 2 on the Hubble Space Telescope reveal a binary
companion to 2002 XH_91 (cf. MPEC 2004-E32).  The two components,
detected in each of four dithered 260-s exposures made through the
F606W (wide-V) filter, were separated by 0".582 +/- 0".009.  The
secondary, fainter by 1.04 magnitude, was located at 0".538 +/-
0".004 in R.A. and 0".222 +/- 0".008 in Decl. relative to the
primary.


V1280 SCORPII
     R. Russell, R. Rudy, and B. Kaneshiro, The Aerospace
Corporation; M. Skinner and S. Gregory, Boeing LTS; and M. Sitko,
University of Cincinnati, report observations of V1280 Sco (Nova
Sco 2007; cf. IAUC 8845) using the "Broadband Array Spectrograph
System" (BASS; range 3-13.5 microns) on the 3.6-m AEOS telescope at
Haleakala on Apr. 6 UT, and the NASA Infrared Telescope Facility
(IRTF) 3-m telescope (+ SpeX; range 2.3-5.5 microns) on Apr. 27.
These spectra exhibit detections of the unidentified infrared bands
near 3.3, 3.4, 8, and 11.4 microns via BASS, and near 3.3 and 3.4
microns via SpeX, along with Brackett-alpha.  The wavelengths are
shifted per the studies of Geballe (1997, ASP Conf. Ser. 122, 119).
These features are superposed on a fairly flat continuum from about
3 to 5 microns.  If a single temperature were associated with the
underlying continuum, it would be on the order of 600-650 K.  After
the initial BASS detection and subsequent SpeX confirmation, SpeX
data from Oct. 2008 were examined more closely, and suggestions of
the 3.3- and 3.4-micron features were seen.
     M. Sitko, Space Science Institute; and R. Russell, D. Lynch,
and R. Rudy, The Aerospace Corporation, report 0.8- to 5.5-micron
spectroscopy of V1280 Sco on May 20.5 UT using the SpeX instrument
of the IRTF.  The excitation of the emission-line spectrum remains
very low, with features of neutral carbon weak but still detectable.
N I is also present, along with very strong lines of Fe II.  O I
features are also prominent, with continuum fluorescence now
rivaling fluorescence by Lyman-beta as the dominant excitation
mechanism.  The reddening deduced from the O I lines is E(B-V) =
0.95.  There is a weak P-Cyg absorption on the He I singlet at
2.058 microns.  The unidentified infrared emission features at 3.3
and 3.4 microns reported above by Russell et al. are also seen.

                      (C) Copyright 2009 CBAT
2009 May 27                    (9046)            Daniel W. E. Green