J/MNRAS/465/3011 VVV high amplitude NIR variable stars (Contreras Pena+, 2017)
A population of eruptive variable protostars in VVV.
Contreras Pena C., Lucas P.W., Minniti D., Kurtev R., Stimson W.,
Navarro Molina C., Borissova J., Kumar M.S.N., Thompson M.A., Gledhill T.,
Terzi R., Froebrich D., Caratti O Garatti A.
<Mon. Not. R. Astron. Soc., 465, 3011-3038 (2017)>
=2017MNRAS.465.3011C 2017MNRAS.465.3011C (SIMBAD/NED BibCode)
ADC_Keywords: Stars, pre-main sequence ; Protostars ; Infrared sources ;
Stars, giant ; Photometry
Keywords: stars: AGB and post-AGB - stars: low-mass - stars: pre-main-sequence -
stars: protostars - stars: variables: T Tauri - Herbig Ae/Be -
infrared: stars
Abstract:
We present the discovery of 816 high-amplitude infrared variable stars
(ΔKs>1mag) in 119deg2 of the Galactic mid-plane covered
by the VISTA Variables in the Via Lactea (VVV) survey. Almost all are
new discoveries and about 50 per cent are young stellar objects
(YSOs). This provides further evidence that YSOs are the commonest
high-amplitude infrared variable stars in the Galactic plane. In the
2010-2014 time series of likely YSOs, we find that the amplitude of
variability increases towards younger evolutionary classes (class I
and flat-spectrum sources) except on short time-scales (<25d) where
this trend is reversed. Dividing the likely YSOs by light-curve
morphology, we find 106 with eruptive light curves, 45 dippers, 39
faders, 24 eclipsing binaries, 65 long-term periodic variables
(P>100d) and 162 short-term variables. Eruptive YSOs and faders tend
to have the highest amplitudes and eruptive systems have the reddest
spectral energy distribution (SEDs). Follow-up spectroscopy in a
companion paper verifies high accretion rates in the eruptive systems.
Variable extinction is disfavoured by the two epochs of colour data.
These discoveries increase the number of eruptive variable YSOs by a
factor of at least 5, most being at earlier stages of evolution than
the known FUor and EXor types. We find that eruptive variability is at
least an order of magnitude more common in class I YSOs than class II
YSOs. Typical outburst durations are 1-4yr, between those of EXors
and FUors. They occur in 3-6 per cent of class I YSOs over a 4yr time
span.
Description:
We present the single epoch ZYJHKs photometry obtained from VVV
catalogues for 816 high-amplitude variables. We also present the
amplitude of the Ks light curve of the objects derived from 2010-2015
photometry. For each object we also provide a provisional
classification derived from the shape of the light curve. For objects
found to be likely associated with SFRs we present an spectral index
derived from the object's spectral energy distribution.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 166 816 Photometric parameters for 816 high amplitude
near-infrared variables from VVV
table1.dat 33 39562 Photometry of 816 high-amplitude variable stars
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See also:
II/337 : VISTA Variables in the Via Lactea Survey DR1 (Saito+, 2012)
II/348 : VISTA Variables in the Via Lactea Survey DR2 (Minniti+, 2017)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name Object identifier (VVVvNNN)
9- 32 A24 --- VVV VVV survey designation
(VVV JHHMMSS.ss+DDMMSS.ss)
34- 35 I2 h RAh Right Ascension (J2000)
37- 38 I2 min RAm Right Ascension (J2000)
40- 44 F5.2 s RAs Right Ascension (J2000)
46 A1 --- DE- Declination sign (J2000)
47- 48 I2 deg DEd Declination (J2000)
50- 51 I2 arcmin DEm Declination (J2000)
53- 57 F5.2 arcsec DEs Declination (J2000)
59- 67 F9.5 deg GLON Galactic longitude
69- 76 F8.5 deg GLAT Galactic latitude
78- 82 F5.2 mag Zmag ?=-9.99 The Z band magnitude
84- 88 F5.2 mag e_Zmag ?=-9.99 Error in Zmag
90- 94 F5.2 mag Ymag ?=-9.99 The Y band magnitude
96-100 F5.2 mag e_Ymag ?=-9.99 Error in Ymag
102-106 F5.2 mag Jmag ?=-9.99 The J band magnitude
108-112 F5.2 mag e_Jmag ?=-9.99 Error in Jmag
114-118 F5.2 mag Hmag ?=-9.99 The H band magnitude
120-124 F5.2 mag e_Hmag ?=-9.99 Error in Hmag
126-130 F5.2 mag Ksmag The Ks band magnitude
132-136 F5.2 mag e_Ksmag Error in Ksmag
138-141 F4.2 mag DeltaKs Ks amplitude of the 2010-2015 light curve
143-147 F5.2 --- alphaClass ?=-9.99 The 2-23um spectral index parameter
that relates to the evolutionary class of
sources that appear to be associated with
SFRs
149 A1 --- SFR [y/n] Whether the object is likely associated
with SFRs or not
151-158 A8 --- Class The classification of the object from its
light curve
160-166 F7.2 d Period ?=-999.99 The approximate period for variable
stars where we are able to measure this
parameter
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name Object identifier (VVVvNNN)
9- 20 F12.7 d Epoch Epoch of observation, MJD-55200
21- 27 F7.3 mag Kmag The Ks magnitude
28- 33 F6.3 mag e_Kmag Error in Kmag
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Acknowledgements:
Carlos Contreras Pena, c.contreras(at)exeter.ac.uk
(End) Patricia Vannier [CDS] 21-Aug-2017