stz1108.pdf (1.17 MB)

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

journal contribution
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.

## 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

1365-2966

15/04/2019

2019

17/06/2019

en