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ABSTRACT The All-Sky Automated Survey for Supernovae (ASAS-SN) provides long baseline (∼4 yr) light curves for sources brighter than V ≲ 17 mag across the whole sky. As part of our effort to characterize the variability of all the stellar sources visible in ASAS-SN, we have produced ∼30.1 million V-band light curves for sources in the Southern hemisphere using the APASS DR9 (AAVSO Photometric All-Sky Survey Data Release) catalogue as our input source list. We have systematically searched these sources for variability using a pipeline based on random forest classifiers. We have identified $${\sim } 220\, 000$$ variables, including $${\sim } 88\, 300$$ new discoveries. In particular, we have discovered $${\sim }48\, 000$$ red pulsating variables, $${\sim }23\, 000$$ eclipsing binaries, ∼2200 δ-Scuti variables, and $${\sim }10\, 200$$ rotational variables. The light curves and characteristics of the variables are all available through the ASAS-SN variable stars data base (https://asas-sn.osu.edu/variables). The pre-computed ASAS-SN V-band light curves for all the ∼30.1 million sources are available through the ASAS-SN photometry data base (https://asas-sn.osu.edu/photometry). This effort will be extended to provide ASAS-SN light curves for sources in the Northern hemisphere and for V ≲ 17 mag sources across the whole sky that are not included in APASS DR9.
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The ASAS-SN catalogue of variable stars VI: an all-sky sample of δ Scuti stars
ABSTRACT We characterize an all-sky catalogue of ∼8400 δ 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 $$\rm [Fe/H]\lt -0.3$$ and log10(P) ∼ −0.9 for $$\rm [Fe/H]\gt 0$$, which leads to a period-dependent scale height. Stars with $$P\gt 0.100\, \rm d$$ are predominantly located close to the Galactic disc ($$\rm |\mathit{ Z}|\lt 0.5\, kpc$$). The median period at a scale height of $$Z\sim 0\, \rm kpc$$ also increases with the Galactocentric radius R, from log10(P) ∼ −0.94 for sources with $$R\gt 9\, \rm kpc$$ to log10(P) ∼ −0.85 for sources with $$R\lt 7\, \rm kpc$$, 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 δ Scuti stars discovered by ASAS-SN. From this sample, we identified two new δ 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.
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- PAR ID:
- 10164488
- Date Published:
- Journal Name:
- Monthly Notices of the Royal Astronomical Society
- Volume:
- 493
- Issue:
- 3
- ISSN:
- 0035-8711
- Page Range / eLocation ID:
- 4186 to 4208
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1093/mnras/staa499
