J/MNRAS/519/5271 New ASAS-SN variable stars using g band lcs (Christy+, 2023)
The ASAS-SN catalogue of variable stars X discovery of 116000 new variable
stars using G-band photometry.
Christy C.T., Jayasinghe T., Stanek K.Z., Kochanek C.S., Thompson T.A.,
Shappee B.J., Holoien T.W.-S., Prieto J.L., Dong S., Giles W.
<Mon. Not. R. Astron. Soc. 519, 5271-5287 (2023)>
=2023MNRAS.519.5271C 2023MNRAS.519.5271C (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Photometry ; Optical ; Cross identifications ;
Positional data
Keywords: catalogues - surveys - stars: variables: general -
binaries: eclipsing - stars: rotation
Abstract:
The All-Sky Automated Survey for Supernovae (ASAS-SN) is the first
optical survey to monitor the entire sky, currently with a cadence of
≲ 24 h down to g ≲ 18.5 mag. ASAS-SN has routinely operated since
2013, collecting ∼2000 to over 7500 epochs of V- and g-band
observations per field to date. This work illustrates the first
analysis of ASAS-SN's newer, deeper, and higher cadence g-band data.
From an input source list of ∼55 million isolated sources with
g<18mag, we identified 1.5 * 106 variable star candidates using a
random forest (RF) classifier trained on features derived from Gaia,
2MASS, and AllWISE. Using ASAS-SN g-band light curves, and an updated
RF classifier augmented with data from Citizen ASAS-SN, we classified
the candidate variables into eight broad variability types. We present
a catalogue of ∼116000 new variable stars with high-classification
probabilities, including ∼111000 periodic variables and ∼5000
irregular variables. We also recovered ∼263000 known variable stars.
Description:
In continuity of previous paper references, we present the first
all-sky catalogue of variables detected in the newer, deeper, higher
cadence g-band ASAS-SN data. The complete list of the crossmatched
variables and the ASAS-SN discoveries along with their g-band light
curves are provided and have been reported to the AAVSO. Since 2018,
ASAS-SN has shifted to using a g-band filter and expanded to 20
cameras on 5 mounts. All of the ASAS-SN telescopes are hosted by the
Las Cumbres Observatory. When compared to the V-band data, the g-band
data have an improved depth, cadence, and more. The field of view of
an ASAS-SN camera is 4.5 deg2, the pixel scale is 8", and the FWHM
is typically ∼2 pixels. The g-band light curves were extracted using
image subtraction and aperture photometry on the subtracted images
with a 2-pixel radius aperture. We corrected the zero point offsets
between the different cameras and photometric errors were recalculated
as described in Jayasinghe et al. (2019MNRAS.485..961J 2019MNRAS.485..961J, Cat. II/366)
(i.e. see more in section 2).
We built a va model with scikit-learn to divide 54.8 million refcat2
sources into two groups as constant stars and potential variables. Our
classifier is trained with 204000 known variables used to train the
RFC variability in Christy et al. (2022PASP..134b4201C 2022PASP..134b4201C). It also use
combination of associated magnitudes and parameters from AllWISE,
GALEX, GaiaEDR3 catalogs. We identified ∼1.48 million variable star
candidates. We extracted ASAS-SN g-band light curves of these
candidates and determined periods using the ASTROPY. Next, as
explicited in section 2.3, we applied the updated variability
classifier to the ∼1.48 million variable star candidates. To reduce
the number of false positives, it left ∼755000 variables. After
checking to multiples variables catalogs, it remains 395494 new
variables in our list.
Then by using the ASAS-SN's citizen science project to our light
curves, we apply new cut to our full variable sample reduced the
number of known and new candidates to gives ∼263000 known variables
and ∼116000 new variables (i.e. see section 2.4 Quality control). As
presented in table.dat with their associated in g-band light curves
folder lcs/, we shows astrometric informations, cross-matched
magnitudes, variablility classes and ML probabilities.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table.dat 512 378861 New and known ASAS-SN V variable stars based on
g-band light curves and cross-matches
lcs/* . 378861 The individual g-band ASAS-SN V time-series
photometry (with file names
ASASSN-V_JHHMMSS.ss+DDMMSS.s.dat)
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See also:
J/MNRAS/505/1476 : Asteroseismic study of TESS mission's DSCTs
(Hasanzadeh+, 2021)
J/MNRAS/496/3257 : The ASAS-SN catalogue of variable stars - VIII
(Bredall+, 2020)
J/MNRAS/464/2672 : ASAS-SN bright supernova catalogue 2013-2014
(Holoien+, 2017)
J/ApJ/867/105 : ATLAS all-sky stellar ref. catalog, ATLAS-REFCAT2
(Tonry+, 2018)
J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)
J/ApJ/696/870 : Catalina Real-time Transient Survey (CRTS) (Drake+, 2009)
J/A+A/653/A160 : Updated radial velocities from Gaia DR2 (Seabroke+, 2021)
J/A+A/389/149 : EROS II periodic stars towards Galactic spiral arm
(Derue+, 2002)
J/ApJS/249/18 : The ZTF catalog of periodic variable stars (Chen+, 2020)
J/ApJS/237/28 : WISE catalog of periodic variable stars (Chen+, 2018)
J/AJ/156/241 : A first catalog of variable stars measured by ATLAS
(Heinze+, 2018)
J/AcA/71/189 : OGLE Galactic bulge and disk delta Scuti
(Soszynski+, 2021)
J/AcA/68/315 : OGLE Galactic Cepheids (Udalski+, 2018)
J/AcA/66/405 : Galactic bulge eclipsing & ellipsoidal binaries
(Soszynski+, 2016)
J/AcA/65/297 : OGLE4 LMC and SMC Cepheids (Soszynski+, 2015)
J/AcA/64/177 : VI light curves of Galactic Bulge RR Lyrae
(Soszynski+, 2014)
J/AcA/63/1 : OGLE-IV Magellanic Bridge Data supernovae
(Kozlowski+, 2013)
J/other/A+ARV/18.67 : Accurate masses and radii of normal stars (Torres+, 2010)
B/vsx : AAVSO International Variable Star Index VSX
(Watson+, 2006-)
I/352 : Distances to 1.47 billion stars in Gaia EDR3
(Bailer-Jones+, 2021)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
II/287 : Northern Sky Variability Survey (NSVS) (Wozniak+, 2004)
II/264 : ASAS Variable Stars in Southern hemisphere
(Pojmanski+, 2002-2005)
II/366 : ASAS-SN catalog of variable stars (Jayasinghe+,2018-2020)
II/322 : OGLE-III. Magellanic Clouds stellar proper motions
(Poleski+, 2012)
Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 28 A28 --- ASAS-SN ASAS-SN name designation as ASASSN-V
JHHMMSS.ss+DDMMSS.s (ID)
30- 41 F12.8 deg RAdeg Right Ascension (J2000) (RAJ2000)
43- 54 E12.8 deg DEdeg Declination (J2000) (DEJ2000)
56- 67 F12.8 deg GLON Galactic longitude (deg) (l)
69- 80 E12.8 deg GLAT Galactic latitude (deg) (b)
82- 86 A5 --- Class Variable star classification from the
ASAS-SN machine learning pipeline
(ML_classification)
88- 92 F5.3 --- Prob Variable star classification probability
from the ASAS-SN machine learning pipeline
(ML_probability)
94- 98 F5.2 mag gmag Mean ASAS-SN g-band magnitude (mag)
(Mean_gmag)
100-103 F4.2 mag Ampg ASAS-SN g-band amplitude (mag) (Amplitude)
105-116 F12.7 d P ? Variability period from ASAS-SN g-band
(Period)
118-130 F13.5 d HJD Ephemeris from ASAS-SN g-band (HJD)
(EpochHJD)
132-135 F4.2 --- LKSL Lafler-Kinmann String Length statistic
(LKSL_statistic)
137-141 A5 --- Discovery ASAS-SN Discovery flag as True for 116027
ASAS-SN discoveries and False for 262834
known variables (ASASSN_Discovery)
143-166 A24 --- GaiaEDR3 Gaia EDR3 source ID (EDR3sourceid)
168-174 F7.4 mas Plx ? Gaia EDR3 parallax (mas) (parallax)
176-181 F6.4 mas e_Plx ? Gaia EDR3 parallax error (mas)
(parallax_error)
183-189 F7.2 --- RPlx ? Gaia EDR3 parallax divided by parallax
error (parallaxovererror)
191-197 F7.3 mas/yr PM ? Gaia EDR3 total proper motion (mas/yr)
(pm)
199-206 F8.3 mas/yr pmRA ? Gaia EDR3 RA proper motion (mas/yr) (pmra)
208-212 F5.3 mas/yr e_pmRA ? Gaia EDR3 RA proper motion error (mas/yr)
(pmra_error)
214-221 F8.3 mas/yr pmDE ? Gaia EDR3 DEC proper motion (mas/yr)
(pmdec)
223-227 F5.3 mas/yr e_pmDE ? Gaia EDR3 DEC proper motion error (mas/yr)
(pmdec_error)
229-234 F6.3 --- RUWE ? Gaia EDR3 renormalized unit weight error
(ruwe)
236-243 F8.5 mag Gmag Gaia EDR3 G-band magnitude (mag)
(photgmean_mag)
245-251 F7.5 mag e_Gmag Gaia EDR3 G-band magnitude error (mag)
(ephotgmeanmag)
253-260 F8.5 mag BPmag ? Gaia EDR3 BP-band magnitude (mag)
(photbpmean_mag)
262-268 F7.5 mag e_BPmag ? Gaia EDR3 BP-band magnitude error (mag)
(ephotbpmeanmag)
270-277 F8.5 mag RPmag ? Gaia EDR3 RP-band magnitude (mag)
(photrpmean_mag)
279-285 F7.5 mag e_RPmag ? Gaia EDR3 RP-band magnitude error (mag)
(ephotrpmeanmag)
287-294 F8.5 mag BP-RP ? Gaia EDR3 BP-RP color (mag) (bp_rp)
296-302 F7.1 pc rpgeo ? Gaia EDR3 probabilistic distance from
Bailer-Jones et al. 2021AJ....161..147B 2021AJ....161..147B,
Cat. I/352 (EDR3_dist)
304-325 A22 --- GALEX GALEX source ID from Bianchi et al.
2017ApJS..230...24B 2017ApJS..230...24B, Cat. II/335 (GALEX_ID)
327-333 F7.4 mag FUVmag ? GALEX FUV magnitude (mag) (FUVmag)
335-340 F6.4 mag e_FUVmag ? GALEX FUV magnitude error (mag) (e_FUVmag)
342-348 F7.4 mag NUVmag ? GALEX NUV magnitude (mag) (NUVmag)
350-355 F6.4 mag e_NUVmag ? GALEX NUV magnitude error (mag) (e_NUVmag)
357-370 A14 --- TIC TESS Input Catalog ID from Paegert et al.
2021arXiv210804778P 2021arXiv210804778P, Cat. IV/39 (TIC_ID)
372-390 A19 --- AllWISE AllWISE source ID from Cutri et al.
2014yCat.2328....0C 2014yCat.2328....0C, Cat. II/328
(AllWISE_ID)
392-397 F6.3 mag W1mag ? AllWISE W1 magnitude (mag) (W1mag)
399-404 F6.3 mag W2mag ? AllWISE W2 magnitude (mag) (W2mag)
406-411 F6.3 mag W3mag ? AllWISE W3 magnitude (mag) (W3mag)
413-418 F6.3 mag W4mag ? AllWISE W4 magnitude (mag) (W4mag)
420-425 F6.3 mag Jmag ? 2MASS J-band magnitude (mag) (Jmag)
427-432 F6.3 mag Hmag ? 2MASS H-band magnitude (mag) (Hmag)
434-439 F6.3 mag Kmag ? 2MASS Ks-band magnitude (mag) (Kmag)
441-445 F5.3 mag e_W1mag ? AllWISE W1 magnitude error (mag) (e_W1mag)
447-451 F5.3 mag e_W2mag ? AllWISE W2 magnitude error (mag) (e_W2mag)
453-457 F5.3 mag e_W3mag ? AllWISE W3 magnitude error (mag) (e_W3mag)
459-463 F5.3 mag e_W4mag ? AllWISE W4 magnitude error (mag) (e_W4mag)
465-469 F5.3 mag e_Jmag ? 2MASS J-band magnitude error (mag)
(e_Jmag)
471-475 F5.3 mag e_Hmag ? 2MASS H-band magnitude error (mag)
(e_Hmag)
477-481 F5.3 mag e_Kmag ? 2MASS Ks-band magnitude error (mag)
(e_Kmag)
483-512 A30 --- Ref ASAS-SN Paper reference (Reference)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: lcs/*
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 F15.6 d HJD Ephemeris from ASAS-SN g-band (HJD)
17- 18 A2 --- Camera ASAS-SN camera names as bB, bj, bn and br
(camera)
20 A1 --- l_gmag Lower limit flag on gmag values
22- 29 F8.4 mag gmag ASAS-SN magnitude in g-band (mag)
31- 40 F10.6 mag e_gmag Uncertainty of gmag (mag_err)
42- 53 F12.6 mJy F Density flux in g-band (flux)
55- 64 F10.6 mJy e_F Uncertainty of Fg (flux_err)
66- 70 A5 --- f_FWHM Flag for stars detections denoted as stars
72- 81 F10.6 pix FWHM ? The FWHM used to derived photometry (FWHM)
83- 96 A14 --- Image Image name in which the source in detected
(IMAGE)
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History:
From electronic version of the journal
References:
Jayasinghe et al. Paper I. 2018MNRAS.477.3145J 2018MNRAS.477.3145J Cat. II/366
Jayasinghe et al. Paper II. 2019MNRAS.486.1907J 2019MNRAS.486.1907J Cat. II/366
Jayasinghe et al. Paper III. 2019MNRAS.485..961J 2019MNRAS.485..961J Cat. II/366
Pawlak et al. Paper IV. 2019MNRAS.487.5932P 2019MNRAS.487.5932P Cat. II/366
Jayasinghe et al. Paper V. 2020MNRAS.491...13J 2020MNRAS.491...13J Cat. II/366
Jayasinghe et al. Paper VI. 2020MNRAS.493.4186J 2020MNRAS.493.4186J Cat. II/366
Jayasinghe et al. Paper VII. 2020MNRAS.493.4045J 2020MNRAS.493.4045J
Bredall et al. Paper VIII. 2020MNRAS.496.3257B 2020MNRAS.496.3257B Cat. J/MNRAS/496/3257
Jayasinghe et al. Paper IX. 2021MNRAS.503..200J 2021MNRAS.503..200J Cat. II/366
Christy et al. Paper X. 2023MNRAS.519.5271C 2023MNRAS.519.5271C This catalog
License: CC-BY-4.0 [see https://spdx.org/licenses/]
(End) Luc Trabelsi [CDS] 11-Mar-2026