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AT 2017fvz: a nova in the dwarf irregular galaxy NGC 6822

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posted on 17.06.2019, 15:43 by MW Healy, MJ Darnley, CM Copperwheat, AV Filippenko, M Henze, JC Hestenes, PA James, KL Page, SC Williams, W Zheng
A transient in the Local Group dwarf irregular galaxy NGC 6822 (Barnard's Galaxy) was discovered on 2017 August 2 and is only the second classical nova discovered in that galaxy. We conducted optical, near-ultraviolet, and X-ray follow-up observations of the eruption, the results of which we present here. This 'very fast' nova had a peak $V$-band magnitude in the range $-7.41>M_V>-8.33$ mag, with decline times of $t_{2,V} = 8.1 \pm 0.2$ d and $t_{3,V} = 15.2 \pm 0.3$ d. The early- and late-time spectra are consistent with an Fe II spectral class. The H$\alpha$ emission line initially has a full width at half-maximum intensity of $\sim 2400$ km s$^{-1}$ - a moderately fast ejecta velocity for the class. The H$\alpha$ line then narrows monotonically to $\sim1800$ km s$^{-1}$ by 70 d post-eruption. The lack of a pre-eruption coincident source in archival Hubble Space Telescope imaging implies that the donor is a main sequence, or possibly subgiant, star. The relatively low peak luminosity and rapid decline hint that AT 2017fvz may be a 'faint and fast' nova.

Funding

The authors would like to thank Mike Shara for his role in refereeing the manuscript, and all those that have contributed to the discussion about this object. MWH acknowledges a PhD studentship from the UK Science and Technology Facilities Council (STFC). MJD received funding from STFC. KLP received funding from the UK Space Agency. The work of AVF’s group at UC Berkeley has been generously supported by the TABASGO Foundation, the Christopher R. Redlich Fund, and the Miller Institute for Basic Research in Science (UC Berkeley); additional funding was provided by NASA/HST grant AR-14295 from the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS5-26555. We thank the staff of the various observatories at which data were obtained. This work made extensive use of the Liverpool Telescope, which is operated by LJMU on the island of La Palma in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from STFC. This work has made use of data from the Asteroid Terrestrial-impact Last Alert System (ATLAS) project. ATLAS is primarily funded to search for new near-Earth asteroids, through NASA grant NN12AR55G issued under the guidance of Lindley Johnson and Kelly Fast. A byproduct of this search is a collection of images and catalogues of the survey area. The ATLAS science products have been made possible through the contributions of the Institute for Astronomy, the University of Hawaii, the Queen’s University Belfast, STScI, and Harvard University. Katzman Automatic Imaging Telescope (KAIT) and its ongoing operation were made possible by donations from Sun Microsystems, Inc., the Hewlett-Packard Company, AutoScope Corporation, Lick Observatory, the NSF, the University of California, the Sylvia & Jim Katzman Foundation, and the TABASGO Foundation. Research at Lick Observatory is partially supported by a g

History

Citation

Monthly Notices of the Royal Astronomical Society, 2019, 486(3), pp. 4334–4347

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy

Version

VoR (Version of Record)

Published in

Monthly Notices of the Royal Astronomical Society

Publisher

Oxford University Press (OUP), Royal Astronomical Society

eissn

1365-2966

Acceptance date

15/04/2019

Copyright date

2019

Available date

17/06/2019

Publisher version

https://academic.oup.com/mnras/article/486/3/4334/5475125

Language

en

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