Variability of V4332 Sgr observed in the near-IR
ATel #4013; W. P. Varricatt, T. Wold, T. Carroll, J. Ehle (Joint Astronomy Centre, Hilo, HI, USA), D. P. K. Banerjee, N. M. Ashok (Physical Research Laboratory, Ahmedabad, India)
on 3 Apr 2012; 05:09 UT
Credential Certification: Watson Varricatt (w.varricatt@jach.hawaii.edu)
Subjects: Infra-Red, Cataclysmic Variable, Variables
We carried out near-IR photometric observations of of the enigmatic variable star V4332 Sgr with the 3.8-m United Kingdom Infrared Telescope (UKIRT) and the UKIRT Wide Field Camera (WFCAM) using the near-IR MKO filters Z, Y, J, H and K (effective wavelengths: 0.8717, 1.0305, 1.2483, 1.6313 and 2.2010 microns respectively) on multiple epochs from 25 May to 6 Oct. 2011. The epochs of observations, filters used and the magnitudes estimated (in the UKIRT-WFCAM photometric system) are given in the table below.
V4332 Sgr was discovered in a nova-like outburst in 1994 (Hayashi S. S. et al. 1994, IAUC # 5942 , 1 ). Later investigations found that the source is different from a nova, it probably hosts a circumstellar disk, and that the outburst may be due to planetary infall (Banerjee, D. P. K. et al. 2004, ApJ, 615, L53) or stellar merger (Tylenda, R. et al. 2005, A&A, 439, 651).
Our new photometric data, when compared with the JHK magnitudes obtained in 2003 June (Banerjee, D. P. K. et al. 2003, ApJ, 598, L31) and in 2009 May (Kamin´ski, T. et al. 2010, A&A, 522, A75) show that the system has brightened continuously from 2003 to 2011. A short period of fading of was seen during our observations when the object got fainter by ~0.1 magnitudes and then started to regain brightness. Observations are encouraged in the optical through near-IR bands to monitor the variability to gain more understanding of this system.
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UTDATE | UT | Heliocentric|Filt.|mag. | error
yyyymmdd | hh:mm:ss | Julian Date | | |
| | 2450000+ | | |
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20110525 | 11:57:24 | 5707.002745 | Y | 13.671 | 0.010
20110619 | 10:49:32 | 5731.956664 | Y | 13.690 | 0.015
20110619 | 10:44:32 | 5731.953192 | H | 10.609 | 0.010
20110619 | 10:46:58 | 5731.954882 | K | 8.817 | 0.010
20110723 | 11:38:47 | 5765.990746 | Y | 13.676 | 0.015
20110723 | 11:21:28 | 5765.978721 | H | 10.599 | 0.010
20110723 | 11:26:28 | 5765.982193 | K | 8.828 | 0.010
20110929 | 06:41:47 | 5833.779635 | Z | 14.880 | 0.010
20110929 | 06:49:43 | 5833.785143 | Y | 13.741 | 0.020
20110929 | 06:57:39 | 5833.790652 | J | 12.380 | 0.010
20110929 | 07:02:30 | 5833.794020 | H | 10.731 | 0.020
20110929 | 07:04:59 | 5833.795744 | K | 8.925 | 0.010
20111002 | 05:40:53 | 5836.737051 | Z | 14.857 | 0.010
20111002 | 05:48:51 | 5836.742583 | Y | 13.734 | 0.010
20111002 | 05:56:47 | 5836.748092 | J | 12.377 | 0.010
20111002 | 06:01:35 | 5836.751425 | H | 10.700 | 0.020
20111002 | 06:24:41 | 5836.767465 | Z | 14.855 | 0.010
20111002 | 06:32:46 | 5836.773078 | Y | 13.738 | 0.010
20111002 | 06:40:44 | 5836.778610 | J | 12.358 | 0.015
20111002 | 06:45:48 | 5836.782128 | H | 10.698 | 0.020
20111002 | 06:48:18 | 5836.783864 | K | 8.884 | 0.020
20111006 | 05:04:17 | 5840.711240 | Z | 14.849 | 0.010
20111006 | 05:12:20 | 5840.716830 | Y | 13.729 | 0.010
20111006 | 05:20:23 | 5840.722420 | J | 12.372 | 0.010
20111006 | 05:25:19 | 5840.725845 | H | 10.655 | 0.010
20111006 | 05:27:55 | 5840.727651 | K | 8.905 | 0.010
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UKIRT is funded by the UK-STFC. The data reduction and distribution are performed by the CASU and WFAU respectively.
A plot of the available near-IR magnitudes is available at: http://www.jach.hawaii.edu/UKIRT/publications/SC/V4332Sgr_ATel_20120403.jpg
