J/ApJ/778/116 V1647 Ori long-term optical & NIR observations (Ninan+, 2013)
Reappearance of McNeil's nebula (V1647 Orionis) and its outburst environment.
Ninan J.P., Ojha D.K., Bhatt B.C., Ghosh S.K., Mohan V., Mallick K.K.,
Tamura M., Henning TH.
<Astrophys. J., 778, 116 (2013)>
=2013ApJ...778..116N 2013ApJ...778..116N
ADC_Keywords: Photometry, VRI ; Equivalent widths ; YSOs ;
Photometry, infrared ; Nebulae
Keywords: accretion, accretion disks; circumstellar matter;
ISM: individual: McNeil's nebula; stars: individual: V1647 Ori;
stars: pre-main sequence
Abstract:
We present a detailed study of McNeil's nebula (V1647 Ori) in its
ongoing outburst phase starting from 2008 September to 2013 March. Our
124 nights of photometric observations were carried out in optical V,
R, I, and near-infrared J, H, K bands, and 59 nights of
medium-resolution spectroscopic observations were done in the
5200-9000Å wavelength range. All observations were carried out with
the 2m Himalayan Chandra Telescope and 2m IUCAA Girawali Telescope.
Our observations show that over the past four and a half years, V1647
Ori and region C near the Herbig-Haro object HH 22A have been
undergoing a slow dimming at a rate of ∼0.04mag/yr and ∼0.05mag/yr,
respectively, in R band, which is six times slower than the rate
during a similar stage of V1647 Ori in the 2003 outburst. We detected
change in flux distribution over the reflection nebula, implying
changes in circumstellar matter distribution between the 2003 and 2008
outbursts. Apart from steady wind of velocity ∼350km/s, we detected
two episodic magnetic reconnection driven winds. Forbidden
[OI]λ6300 and [FeII]λ7155 lines were also detected,
implying shock regions probably from jets. We tried to explain the
outburst timescales of V1647 Ori using the standard models of the
FUors kind of outburst and found that pure thermal instability models
like Bell and Lin cannot explain the variations in timescales. In the
framework of various instability models we conclude that one possible
reason for the sudden ending of the 2003 outburst in 2005 November was
a low-density region or gap in the inner region (∼1AU) of the disk.
Description:
Our long-term optical observations span from 2008 September 14 to 2013
March 11 and were carried out with the 2m Himalayan Chandra Telescope
(HCT) at the Indian Astronomical Observatory, Hanle (Ladakh), India,
and with the 2m Inter-University Centre for Astronomy and Astrophysics
(IUCAA) Girawali Telescope at the IUCAA Girawali Observatory (IGO),
Girawali (Pune), India. V1647 Ori's field, (RAJ2000=05:46:13.135,
DEJ2000=-00:06:04.82), was observed in standard VRI Bessel filters.
Our long-term spectroscopic observations also span the same duration
as that of photometric observations (2008 September to 2013 March)
using both 2m HCT and 2m IGO.
Along with optical monitoring we also carried out photometric
monitoring (2007 Oct to 2012 Nov) in JHK bands using the HCT NIR
camera (NIRCAM) and TIFR NIR Imaging Camera-II (TIRCAM2).
Filters used for observation were
J (λcenter=1.28um, Δλ=0.28um),
H (λcenter=1.66um, Δλ=0.33um), and
K (λcenter=2.22um, Δλ=0.38um).
Objects:
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RA (ICRS) DE Designation(s)
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05 46 13.135 -00 06 04.82 V1647 Ori = V* V1647 Ori
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 62 135 Observation log of the photometric and
spectroscopic observations
table2.dat 45 106 Optical VRI photometry of V1647 Ori and region C
table3.dat 36 14 NIR JHK photometry of V1647 Ori
table4.dat 46 70 Equivalent widths of optical lines in V1647 Ori
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See also:
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
II/183 : UBVRI Photometric Standards (Landolt 1992)
J/AJ/147/140 : SED of class I and class II FU Orionis stars (Gramajo+, 2014)
J/AJ/144/192 : Spitzer survey of Orion A and B. I. YSOs (Megeath+, 2012)
J/MNRAS/418/863 : NLTE corrections for Mg and Ca lines (Merle+ 2011)
J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 "YYYY/MMM/DD" Date UT date of the observation
13 A1 --- f_Date [d] Indicates an IGO observation (G1)
15- 21 I7 d JD Julian Date of the observation
23- 25 F3.1 arcsec FWHM [0.8/3.8] Measured FWHM of the seeing
27- 39 A13 --- Filter Filter(s) or grism(s) set up
41- 62 A22 s Exp Exposure time(s)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 I7 d JD Julian Date of the observation
9 A1 --- f_JD [d] Indicates an IGO observation (G1)
11- 15 F5.2 mag Vmag [18.7/19.8]? V band magnitude of V1647 Ori (2)
17- 21 F5.2 mag Rmag [16.8/17.5]? R band magnitude of V1647 Ori (2)
23- 27 F5.2 mag Imag [14.8/15.4]? I band magnitude of V1647 Ori (2)
29- 33 F5.2 mag VmagC [15.4/16]? V band magnitude of region C (2)
35- 39 F5.2 mag RmagC [14.8/15.4]? R band magnitude of region C (2)
41- 45 F5.2 mag ImagC [14.2/14.8]? I band magnitude of region C (2)
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Note (2): Estimated error in magnitude of V1647 Ori is ≤±0.05 for V
and ≤±0.02 for R and I. Estimated error in magnitude of
region C is ≤±0.02 for V, R and I.
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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- 11 A11 "YYYY/MMM/DD" Date UT date of the observation
13- 17 F5.2 mag Jmag J-band magnitude
19- 23 F5.2 mag Hmag H-band magnitude
25- 28 F4.2 mag Kmag ? K-band magnitude
30- 36 A7 --- Inst Instrument (NIRCAM or TIRCAM2)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 7 I7 d JD Julian Date of the observation
9 A1 --- f_JD [d] Indicates an IGO observation (G1)
11- 16 F6.2 0.1nm EWHa [-42.1/-14] Hα equivalent width; Å (2)
18- 24 F7.3 0.1nm EW8498 ? CaII 8498 equivalent width; Angstroms (2)
26- 32 F7.3 0.1nm EW8542 ? CaII 8542 equivalent width; Angstroms (2)
34- 40 F7.3 0.1nm EW8662 ? CaII 8662 equivalent width; Angstroms (2)
42- 46 F5.3 0.1nm EW7773 ? OI 7773 equivalent width; Angstroms (2)
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Note (2): Estimated error in equivalent widths of Hα lines is ~±3Å,
error for Ca II IR triplet lines is ~±0.5 Angstroms and the error
for O I λ7773 lines is ±0.3 Angstroms.
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Global Notes:
Note (G1): Flagged observations are IGO, other ones are HCT
IGO = 2m IUCAA Girawali Observatory (Pune, India)
HCT = 2m Himalayan Chandra Telescope at Hanle (Ladakh, India)
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 24-Apr-2015