J/MNRAS/442/273 IR photometry of NGC 1893 variables (Lata+, 2014)
Main-sequence variable stars in young open cluster NGC 1893.
Lata S., Yadav R.K., Pandey A.K., Richichi A., Eswaraiah C., Kumar B.,
Kappelmann N., Sharma S.
<Mon. Not. R. Astron. Soc., 442, 273-284 (2014)>
=2014MNRAS.442..273L 2014MNRAS.442..273L (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, variable ; Photometry, infrared
Keywords: stars: variables: general -
open clusters and associations: NGC 1893
Abstract:
In this paper, we present time series photometry of 104 variable stars
in the cluster region NGC 1893. The association of the present
variable candidates to the cluster NGC 1893 has been determined by
using (U-B)/(B-V) and (J-H)/(H-K) two colour diagrams, and V/(V-I)
colour-magnitude diagram. 45 stars are found to be main-sequence
variables and these could be B-type variable stars associated with the
cluster. We classified these objects as β Cep, slowly pulsating B
stars and new class variables as discussed by Mowlavi et al. (2013,
Cat. J/A+A/554/A108). These variable candidates show ∼0.005 to
∼0.02mag brightness variations with periods of <1.0d. 17 new class
variables are located in the H-R diagram between the slowly pulsating
B stars and δ Scuti variables. Pulsation could be one of the
causes for periodic brightness variations in these stars. The X-ray
emission of present main-sequence variables associated with the
cluster lies in the saturated region of X-ray luminosity versus period
diagram and follows the general trend by Pizzolato et al. (2003, Cat.
J/A+A/397/147).
Description:
The present work uses observations made from two telescopes; 104-cm
ARIES telescope and 130-cm Devasthal telescope. The details of these
two telescopes and instrument are given below. The photometric
observations of the NGC 1893 region were carried out in the V-band on
15 nights and in the I-band on two nights during 2007 December 05 to
2013 January 05 using a 2048x2048 CCD camera attached to the 104-cm
Sampurnanand ARIES telescope at Nainital.
In addition, we have also observed the region in V-band on 22 December
2012 using 130-cm Devasthal telescope.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 121 104 The present photometric data, NIR data, period,
amplitude and classification of 104 variables
in the region of NGC 1893
--------------------------------------------------------------------------------
See also:
J/A+A/397/147 : Activity-rotation relationship in stars (Pizzolato+ 2003)
J/A+A/488/211 : Infrated photometry of NGC 1893 (Caramazza+, 2008)
J/A+A/527/A77 : NGC 1893 optical and NIR photometry (Prisinzano+, 2011)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- VName Variable name (VNNN)
5- 6 A2 -- n_VName [* ] Note on VName (1)
7- 14 F8.5 deg RAdeg Right ascension (J2000)
16- 23 F8.5 deg DEdeg Declination (J2000)
25- 30 F6.3 mag Vmag V magnitude
32- 36 F5.3 mag V-I V-I colour index
38- 43 F6.3 mag Jmag ?=- 2MASS J magnitude (2)
45- 50 F6.3 mag Hmag ?=- 2MASS H magnitude (2)
52- 57 F6.3 mag Kmag ?=- 2MASS K magnitude (2)
59- 64 F6.3 mag Jmko ?=- MKO J magnitude (TNG/NICS Js) (2)
66- 71 F6.3 mag Hmko ?=- MKO H magnitude (TNG/NICS H) (2)
73- 78 F6.3 mag Kmko ?=- MKO K magnitude (TNG/NICS K') (2)
80- 84 F5.3 d Per Period
85 A1 --- --- [/]
86- 90 F5.3 d Per2 ? Second period value
91 A1 --- --- [/]
92- 96 F5.3 d Per3 ? Third period value
97 A1 --- --- [/]
98-102 F5.3 d Per4 ? Fourth period value
104-108 F5.3 mag Amp Amplitude of variation
110-121 A12 --- Class Classification
--------------------------------------------------------------------------------
Note (1): Notes as follows:
* = O/B/Be-type stars from Marco & Negueruela (2002, ASP Conf. Ser. Vol 267,
p. 289a, 2002A&A...393..195M 2002A&A...393..195M)
** = PMS stars from Marco & Negueruela (2002, ASP Conf. Ser. Vol 267,
p. 289a, 2002A&A...393..195M 2002A&A...393..195M)
Note (2): The NIR data have been taken from Prisinzano et al. (2011,
Cat. J/A+A/527/A77) and 2MASS point source catalogue
(Cutri et al., 2003, Cat. II/246/).
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 14-Dec-2015