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ASASSN-17nj Gaia and Spitzer GLIMPSE progenitor counterparts

ATel #10862; Peter Pessev (GRANTECAN, IAC, ULL)
on 17 Oct 2017; 22:16 UT
Credential Certification: Peter Pessev (peter.pessev@gtc.iac.es)

Subjects: Infra-Red, Optical, Nova

ASASSN-17nj was discovered by Stanek et al. 2017 (ATel #10850) on UT 2017-10-14.01 and was confirmed as Galactic Nova by Joshi, Banerjee and Srivastava 2017 (ATel #10852), based on NIR spectroscopy. Saito and Minniti 2017 (ATel #10857) identified the possible progenitor from VVV Survey (vvvsurvey.org; Minniti et al. 2010, New Astronomy, 15, 433) archival data and reported no significant variation in the Ks observations during the 2010-2012 period. GAIA and Spitzer GLIMPSE 3D archival data are presented to expand the wavelength coverage and better constrain the nature of the progenitor. All positions and distances are reported with respect of the VVV progenitor position, reported by Saito and Minniti (ATel #10857).

GAIA DR1 gives a 19.7595 mag source (4057953206583126400) 0.159383 arc-seconds away at a PA of 144.028451 degrees, no variability information available.

The GLIMPSE 3D database contains two epochs of photometry that does not show variability within the error bars of the data, coinciding with the results from the VVV survey data. The GLIMPSE 3D data for the source G356.4269+01.5934 is summarized below.

Epoch 1
[3.6] = 13.233 +/- 0.097
[4.5] = 13.325 +/- 0.173
[3.6 - 4.5] = -0.092 +/- 0.198
0.12598 arc-seconds away at a PA of 140.493183 degrees

Epoch 2007-2009
[3.6] = 13.161 +/- 0.084
[4.5] = 13.218 +/- 0.145
[3.6 - 4.5] = -0.057 +/- 0.168
0.076717 arc-seconds away at a PA of 142.928439 degrees

There is no 2MASS PSC counterpart at the progenitor position. Although the mean Ks magnitude reported by ATel #10857 13.699+/-0.036 is about 0.6 magnitudes brighter by the SNR=10 limit requirement of 2MASS, the detection and photometry of sources in crowded fields close to the bulge could be significantly affect by confusion. Hence the absence of detection should not be interpreted as significant brightening of the progenitor system between the 2MASS and VVV epoch(s). The closest reported 2MASS PCS source is a Ks=11.255 magnitude star ~5.5 arc-seconds away at a PA~218 degrees.

This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation.