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CO detected strongly in emission in Nova Sgr 2015 #2

ATel #7303; D. P. K. Banerjee, N. M. Ashok, V. Venkataraman and M. Srivastava (Physical Research Laboratory, Ahmedabad, India)
on 28 Mar 2015; 02:21 UT
Credential Certification: Dipankar P.K. Banerjee (orion@prl.res.in)

Subjects: Infra-Red, Nova

Referred to by ATel #: 7748, 10557

In addition to near-IR spectra of Nova Sgr 2015 #2 reported in ATel #7265 and ATel #7299, spectra were also obtained on 2015 March 27.0 UT with the Mount Abu 1.2 meter telescope and the Near-Infrared Imager/Spectrograph (NICS). The significant finding of this latest observation is the detection of strong first overtone CO emission bands in the K band. The first six bandheads from (2-0) to (7-5) are seen; the first four bandheads are known to occur at 2.2935, 2.3227, 2.3535 and 2.2829 microns. Visual inspection shows that 13C is also present but the extent of its enhancement, relative to 12C, needs to be assessed (novae may produce a ratio of 13C/12C as high as unity). The known instances of first overtone CO detection in novae are few (about 10) and all such novae have proceeded to produce significant dust. Dust formation in Nova Sgr 2015 #2 is therefore very likely as pointed in our earlier ATel #7299.