[vsnet-alert 8797] Unusual spectrum of NSV 19448 = HD 109962

Howard E. Bond bond at stsci.edu
Thu Jan 19 11:24:21 JST 2006

Hello everyone,

In response to [vsnet-alert 8794], we obtained a spectrum of HD 109962 = NSV
19448 with the SMARTS 1.5m telescope at Cerro Tololo.  It shows He II 4686 A
emission superposed on the F2 V spectrum, which appears to rule out Otero's
suggestion of a Mira variable blended with the short-period eclipsing binary. 
Instead, the spectrum may suggest that there is a hot source in the system,
possibly an accreting compact object in an eccentric orbit around the F-type

We will be sending the following message to the IAU Circulars:


F. Walter (Stony Brook University), H. E. Bond (Space Telescope Science
Institute), and A. Pasten (Cerro Tololo Interamerican Observatory) report that a
spectrum obtained with the SMARTS 1.5m spectrograph of HD 109962 (= NSV 19448)
on 2006 January 16.2 shows He II 4686 A emission (equivalent width -2.9 A)
superposed on the F2 V spectrum. As described by S. Otero
(http://ar.geocities.com/varsao/NSV_19448.htm), HD 109962 is an eclipsing binary
with a period of 0.89 days that in addition shows outbursts of ~0.8 mag and
duration ~40 days occurring every 360 days, according to ASAS-3 data, with the
latest outburst having begun in late December 2005.  Observations at all
wavelengths, including X-ray and UV, are strongly encouraged.


We urge continued observations by all of you in the southern hemisphere!

best regards,
Howard E. Bond
Space Telescope Science Institute

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