J/AJ/145/59 Optical and mid-IR photometry of PTF 10nvg (Hillenbrand+, 2013)
Highly variable extinction and accretion in the jet-driving class I-type young
star PTF 10nvg (V2492 Cyg, IRAS 20496+4354).
Hillenbrand L.A., Miller A.A., Covey K.R., Carpenter J.M., Cenko S.B.,
Silverman J.M., Muirhead P.S., Fischer W.J., Crepp J.R., Bloom J.S.,
Filippenko A.V.
<Astron. J., 145, 59 (2013)>
=2013AJ....145...59H 2013AJ....145...59H
ADC_Keywords: Stars, variable ; Photometry, RI ; Photometry, infrared
Keywords: stars: formation - stars: pre-main sequence -
stars: individual (V2492 Cyg,PTF 10nvg,IRAS 20496+4354)
Abstract:
We report extensive new photometry and spectroscopy of the highly
variable young stellar object PTF 10nvg (also known as IRAS 20496+4354
and V2492 Cyg), including optical and near-infrared time-series data
as well as mid-infrared and millimeter data. Following the previously
reported 2010 rise to RPTF≲13.5m and subsequent fade, during 2011
and 2012 the source underwent additional episodes of brightening,
followed by several magnitude dimming events including prolonged faint
states at RPTF≳20m. The observed high-amplitude variations are
largely consistent with extinction changes (ΔAV up to 30mag)
having a ∼220day quasi-periodic signal. However, photometry measured
when the source was near maximum brightness in mid-2010 as well as in
late-2012 does not phase well to this period. Spectral evolution
includes not only changes in the spectral slope but also correlated
variation in the prominence of TiO/VO/CO bands and atomic line
emission, as well as anti-correlated variation in forbidden line
emission which, along with H2, dominates optical and infrared
spectra at faint epochs. Notably, night-to-night variations in several
forbidden doublet strengths and ratios are observed. High-dispersion
spectra were obtained in a variety of photometric states and reveal
time-variable line profiles. Neutral and singly ionized atomic species
are likely formed in an accretion flow and/or impact while the origin
of zero-velocity atomic LiIλ6707 in emission is unknown.
Forbidden lines, including several rare species, exhibit blueshifted
emission profiles and likely arise from an outflow/jet. Several of
these lines are also seen spatially offset from the continuum source
position, presumably in a shocked region of an extended jet.
Blueshifted absorption components of the NaI D doublet,
KIλλ7665,7669 doublet, and the OI 7774 triplet, as well
as blueshifted absorption components seen against the broad Hα
and CaII triplet emission lines, similarly are formed in the outflow.
CARMA maps resolve on larger scales a spatially extended outflow in
millimeter-wavelength CO. We attribute the recently observed
photometric and spectroscopic behavior to rotating circumstellar disk
material located at separation a∼0.7(M*/M☉)1/3AU from the
continuum source, causing the semi-periodic dimming. Occultation of
the central star as well as the bright inner disk and the
accretion/outflow zones renders shocked gas in the inner part of the
jet amenable to observation at the faint epochs. We discuss PTF 10nvg
as a source exhibiting both accretion-driven (perhaps analogous to
V1647 Ori) and extinction-driven (perhaps analogous to UX Ori or GM
Cep) high-amplitude variability phenomena.
Description:
Continued optical monitoring of PTF 10nvg was conducted as part of the
regular observations of the greater North America Nebula field with
the main PTF Survey Camera on the 48inch Samuel Oschin Telescope at
Palomar Observatory (hereafter P48). All observations were taken with
60 s exposures in the RPTF filter, a Mould R filter that is similar
to the SDSS-r band. P48 observations from 2009 August to 2010 December
are presented in Covey et al. (2011AJ....141...40C 2011AJ....141...40C); the new
observations reported here started in 2011 February and continued
through 2012 October.
Continued near-infrared monitoring of PTF 10nvg was conducted with the
1.3m Peters Automated Infrared Imaging Telescope (PAIRITEL) on Mt.
Hopkins, AZ. PAIRITEL is a robotic system using the former Two Micron
All Sky Survey (2MASS) Southern Hemisphere survey camera that employs
two dichroics to observe simultaneously in the J, H, and Ks bands.
Observations were scheduled and executed via a robotic system.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
20 51 26.23 +44 05 23.9 PTF 10nvg = V2492 Cyg
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 23 741 *P48 R-band photometry of PTF 10nvg
table3.dat 52 167 *PAIRITEL JHK-band photometry of PTF 10nvg
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Note on table1.dat: P48 is the 48inch Samuel Oschin Telescope at Palomar
Observatory.
Note on table3.dat: PAIRITEL is the 1.3m Peters Automated Infrared Imaging
Telescope on Mt. Hopkins.
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See also:
B/iram : IRAM Observation Logs (IRAM 1991-2014)
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
J/A+A/551/A62 : V2492 Cyg light variations (Kospal+, 2013)
J/ApJS/193/25 : The NAN complex. II. MIPS observations (Rebull+, 2011)
J/ApJ/733/50 : Mid-IR photometry of the ONC (Morales-Calderon+, 2011)
J/ApJS/188/123 : The Bolocam Galactic Plane Survey. II. (Rosolowsky+, 2010)
J/AJ/140/1214 : NIR spectroscopic survey of class I YSOs (Connelley+, 2010)
J/MNRAS/406/2473 : Photometry of GRB 071025 (Perley+, 2010)
J/ApJ/691/723 : BVIJHKs observations of GRB 080319B (Bloom+, 2009)
J/AJ/113/1733 : Orion Nebula Cluster population (Hillenbrand 1997)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 d MJD Modified Julian Date of observation
11 A1 --- l_Rmag [>] Lower limit flag on Rmag
12- 17 F6.3 mag Rmag [13.471/20.637] The R band magnitude
19- 23 F5.3 mag e_Rmag ? Error in Rmag
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 d MJD Modified Julian Date of observation
11- 16 F6.3 mag Jmag [10.896/18.121] 2MASS J band magnitude
18- 22 F5.3 mag e_Jmag Error in Jmag
24- 29 F6.3 mag Hmag [9.414/13.94] 2MASS H band magnitude
31 A1 --- f_Hmag [s] Photometric flag on Hmag (s) (1)
33- 37 F5.3 mag e_Hmag Error in Hmag
39- 44 F6.3 mag Kmag [8.029/10.98]? 2MASS Ks band magnitude
46 A1 --- f_Kmag [sn] Photometric flag on Kmag (s or n) (1)
48- 52 F5.3 mag e_Kmag ? Error in Kmag
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Note (1): Flag as follows:
s = Photometry measured on short read PAIRITEL (Peters Automated Infrared
Imaging Telescope) images (see Section 2.1.2 for more details).
n = No reliable photometric measurements are available due to large thermal
backgrounds (see Section 2.1.2 for more details).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 25-Mar-2014