The ASAS-SN catalogue of variable stars VI: an all-sky sample of delta Scuti stars

Article

The ASAS-SN catalogue of variable stars VI: an all-sky sample of delta Scuti stars

Jayasinghe, T.; Stanek, K. Z.; Kochanek, C. S.; Vallely, P. J.; Shappee, B. J.; Holoien, T. W. -S.; Thompson, Todd A.; Prieto, J. L.; Pejcha, O.; Fausnaugh, M.; Otero, S.; Hurst, N.; Will, D.

Mon. Not. R. Astron. Soc. 493(0), 4186-4208 (2020)

doi ↗ arXiv:1910.14187 ↗

Abstract

We characterize an all-sky catalogue of ~8400 d Scuti variables in ASAS-SN, which includes ~3300 new discoveries. Using distances from Gaia DR2, we derive period-luminosity relationships for both the fundamental mode and overtone pulsators in the WJK, V, Gaia DR2 G, J, H, Ks, and W1 bands. We find that the overtone pulsators have a dominant overtone mode, with many sources pulsating in the second overtone or higher order modes. The fundamental mode pulsators have metallicity-dependent periods, with log10(P) ~ -1.1 for [Fe/H]< -0.3 and log10(P) ~ -0.9 for [Fe/H]> 0, which leads to a period-dependent scale height. Stars with P> 0.100 d are predominantly located close to the Galactic disc (|Z|< 0.5 kpc). The median period at a scale height of Z~ 0 kpc also increases with the Galactocentric radius R, from log10(P) ~ -0.94 for sources with R> 9 kpc to log10(P) ~ -0.85 for sources with R< 7 kpc, which is indicative of a radial metallicity gradient. To illustrate potential applications of this all-sky catalogue, we obtained 30 min cadence, image subtraction TESS light curves for a sample of 10 fundamental mode and 10 overtone d Scuti stars discovered by ASAS-SN. From this sample, we identified two new d Scuti eclipsing binaries, ASASSN-V J071855.62-434247.3 and ASASSN-V J170344.20-615941.2 with short orbital periods of Porb = 2.6096 and 2.5347 d, respectively.

Institute authors

Pejcha, Ondřej

Supported by

ERC 803158 — Cat-In-hAT: Catastrophic Interactions of Binary Stars and the Associated Transients, Horizon 2020 ERC Starting Grant 803158
MSMT LTAUSA18093 — Časová proměnnost v astronomii: účast v projektu All-Sky Automated Survey for Supernovae
Primus/17/SCI/17 — Teorie a pozorování astronomických tranzientů: supernovy z hmotných hvězd a splynutí hvězd

BibTeX

@article{UTF817,
  author        = {Jayasinghe, T. and Stanek, K. Z. and Kochanek, C. S. and Vallely, P. J. and Shappee, B. J. and Holoien, T. W. -S. and Thompson, Todd A. and Prieto, J. L. and Pejcha, O. and Fausnaugh, M. and Otero, S. and Hurst, N. and Will, D.},
  title         = {{The ASAS-SN catalogue of variable stars VI: an all-sky sample of delta Scuti stars}},
  journal       = {Mon. Not. R. Astron. Soc.},
  volume        = {493},
  number        = {0},
  pages         = {4186-4208},
  year          = {2020},
  doi           = {10.1093/mnras/staa499},
  eprint        = {1910.14187},
  archivePrefix = {arXiv},
}