J/MNRAS/408/181 CN2002ch UBVRI and ugriz light curves (Pastorello+, 2010)
Multiple major outbursts from a restless luminous blue variable in NGC 3432.
Pastorello A., Botticella M.T., Trundle C., Taubenberger S., Mattila S.,
Kankare E., Elias-Rosa N., Benetti S., Duszanowicz G., Hermansson L.,
Beckman J.E., Bufano F., Fraser M., Harutyunyan A., Navasardyan H.,
Smartt S.J., Van Dyk S.D., Vink J.S., Wagner R.M.
<Mon. Not. R. Astron. Soc., 408, 181-198 (2010)>
=2010MNRAS.408..181P 2010MNRAS.408..181P
ADC_Keywords: Supernovae ; Stars, blue ; Stars, luminous ; Photometry, UBVRI ;
Photometry, SDSS
Keywords: supernovae: general - supernovae: individual: 2000ch -
galaxies: individual: NGC 3432
Abstract:
We present new photometric and spectroscopic observations of an
unusual luminous blue variable (LBV) in NGC 3432, covering three major
outbursts in 2008 October, 2009 April and 2009 November. Previously,
this star experienced an outburst also in 2000 (known as SN 2000ch).
During outbursts the star reached an absolute magnitude between -12.1
and -12.8. Its spectrum showed H, HeI and FeII lines with P-Cygni
profiles during and soon after the eruptive phases, while only
intermediate-width lines in pure emission (including HeII
λ4686) were visible during quiescence. The fast-evolving light
curve soon after the outbursts, the quasi-modulated light curve, the
peak magnitude and the overall spectral properties are consistent with
multiple episodes of variability of an extremely active LBV. However,
the widths of the spectral lines indicate unusually high wind
velocities (1500-2800km/s), similar to those observed in Wolf-Rayet
stars. Although modulated light curves are typical of LBVs during the
S-Dor variability phase, the luminous maxima and the high frequency of
outbursts are unexpected in S-Dor variables.
Description:
After the discovery by Duszanowicz et al. (2008CBET.1534....1N 2008CBET.1534....1N), we
started a systematic monitoring of the variable in the optical bands.
At the same time, we collected a number of pre-discovery images of NGC
3432 from amateur astronomers and professional telescopes available
through science data archives. The calibration of the optical
photometry obtained with standard Johnson-Bessell filters has been
performed using the local standard star magnitudes presented in Wagner
et al. (2004PASP..116..326W 2004PASP..116..326W) for the B, V and R bands, while the U and
I band data have been calibrated independently. The calibration of the
Sloan filter photometry was performed using the SDSS photometry
catalogue
Objects:
---------------------------------------------------
RA (2000) DE Designation(s)
---------------------------------------------------
10 52 41.40 +36 40 09.5 SN 2000ch = SN 2000ch
---------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 95 112 Unpublished Johnson-Bessell photometry of the
variable star in NGC 3432
table2.dat 86 65 Sloan-filter photometry of the variable star
in NGC 3432 and associated errors
--------------------------------------------------------------------------------
See also:
B/sn : Asiago Supernova Catalogue (Barbon et al., 1999-)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 "YYYY/MMM/DD" Date Date of observations
12 A1 --- n_Date [m] m indicates first maxima (1)
14- 23 F10.2 --- JD Average Julian Date of observation
24 A1 --- n_JD [m] m indicates first maxima (1)
26 A1 --- l_Umag Limit flag on Umag
27- 31 F5.2 mag Umag ? Johnson U band magnitude
33- 36 F4.2 mag e_Umag ? rms uncertainty on Umag
37 A1 --- l_Bmag Limit flag on Bmag
38- 42 F5.2 mag Bmag ? Johnson B band magnitude
44- 47 F4.2 mag e_Bmag ? rms uncertainty on Bmag
48 A1 --- n_Bmag [*] Note on error (2)
50 A1 --- l_Vmag Limit flag on Vmag
51- 55 F5.2 mag Vmag ? Johnson V band magnitude
57- 60 F4.2 mag e_Vmag ? rms uncertainty on Vmag
61 A1 --- n_Vmag [*] Note on error (2)
63 A1 --- l_Rmag Limit flag on Rmag
64- 68 F5.2 mag Rmag ? Johnson R band magnitude
70- 73 F4.2 mag e_Rmag ? rms uncertainty on Rmag
74 A1 --- n_Rmag [*] Note on error (2)
76 A1 --- l_Imag Limit flag on Imag
77- 81 F5.2 mag Imag ? Johnson I band magnitude
83- 86 F4.2 mag e_Imag ? rms uncertainty on Imag
88- 91 A4 --- Tel Telescope (3)
92- 94 A3 --- Note Source of the data (4)
95 A1 --- Flag [*] Rescaled to R-band (5)
--------------------------------------------------------------------------------
Note (1): m indicates the epochs and magnitudes of the first maxima of
the four major outbursts.
Note (2): * indicates errors associated to the SN photometry, and
include both measurement and photometric calibration uncertainties.
Note (3): Telescopes as follows:
INT = 2.54-m Isaac Newton Telescope + CCD-EEV5 (La Palma, Canary Islands,
Spain)
KISO = 1.05-m Schmidt Telescope + TC215-1K CCD (Kiso Observatory, Inst. of
Astronomy, University of Tokyo, Japan)
IRO = 0.37-m f/14 Rigel Telescope + FLI with SITe-003 CCD (Obs. Chris Anson,
Winer Observatory, Sonoita, Arizona, US)
KAIT = 0.76-m Katzman Automatic Imaging Telescope + CCD (Lick Observatory,
Mt. Hamilton, California, US
TT = 0.4-m Meade LX200 Telescope + SBIG ST-8 CCD (Obs. T. Tamura,
Kagawa, Japan)
HALE = Hale 5.08-m Telescope + COSMIC direct imaging 2048x2048 SITe thinned
CCD (Palomar Observatory, San Diego County, California, US
GY = Takahashi FS-128G Telescope + SBIG ST-10 Dual CCD Camera (Obs. G.
Youman, Penryn, California, US)
MO = 0.32-m f/3.1 Newton Telescope + Starlight Xpress MX716 CCD (Obs. G.D.,
Moonbase Observatory, Akersberga, Sweden)
CD = 0.46-m f/2.8 Centurion Telescope + ST8E CCD camera (Obs. C. Deforeit,
Caen, Normandie, France)
RJ = 0.356-m f/10 LX200R Meade Telescope + SBIG STL-11000XM CCD camera
(Obs. R. Johnson, Mantrap Lake, Minnesota, US)
TKC = 0.3-m Ritchey-Chretien Telescope + Apogee Alta U9000 CCD (Kazan State
Univ., Astrotel Obs., Karachay-Cherkessia, Russia)
KI = 0.60-m f/5.7 Reflector Telescope + KAF-1001E 1024x1024pixel CCD
(Obs. Koichi Itagaki, Yamagata, Japan)
CAHA = 2.2-m Calar Alto Telescope + CAFOS (German-Spanish Astron. Center,
Sierra de Los Filabres, Andalucia, Spain)
TNG = 3.58-m Telescopio Nazionale Galileo + Dolores (Fundacion Galileo
Galilei-INAF, La Palma, Canary Islands, Spain)
LT = 2.0-m Liverpool Telescope + RatCAM (La Palma, Canary Islands, Spain)
SO = 0.44-m f/4.4 Newton Telescope + SBIG ST-7E Dual CCD (Obs. L.H.,
Sandvreten Obs., Uppsala, Sweden)
HST = Hubble Space Telescope + WFPC camera (P.I. W. Li; proposal ID:10877)
EK = 1.82-m Copernico Telescope + AFOSC (INAF - Osservatorio Astronomico
di Asiago, Mt. Ekar, Asiago, Italy)
NOT = 2.56m Nordic Optical Telescope + ALFOSC (La Palma, Canary Islands,
Spain)
UVOT = Swift Gamma-Ray Burst Explorer + UVOT (proposal ID 00036566001)
BH = Meade LX200 12" f-6.3 telescope + SBIG ST-10 Dual CCD Camera
(Obs. B. Hausler, Rimpar, Germany)
P60 = Palomar 60-inch Telescope + CCD camera (Palomar Mountain,
San Diego County, California, US)
EP = Meade LX200 12" f-6.3 telescope + ST10XME CCD (Obs. E. Prosperi,
Osservatorio Remoto Skylive, Pedara, Catania, Italy)
Note (4): Notes as follows:
(a) = ING archive: http://casu.ast.cam.ac.uk/casuadc/archives/ingarch
(b) = Subaru-Mitaka-Okayama-Kiso Archive System
(Baba et al. 2002, ASP Conf. Ser., 281, 298)
(c) = Template image from the Supernova Search in Late-type Galaxies using
the 0.37-m Rigel Robotic Telescope (Winer Observatory - University of
Iowa; http://phobos.physics.uiowa.edu/images/snsearch.html)
(d) = Measurement from Wagner et al. (2004PASP..116..326W 2004PASP..116..326W)
(e) = Astrodon Generation 1 Series I Luminance filter
(f) = Kryachko and Korotkiy estimated R=17.65 for 2008-OT with reference
to star USNO-A2.0 1200-06602541 (USNOR=14.0), which is coincident
with star D in the sequence of Wagner et al. (2004PASP..116..326W 2004PASP..116..326W);
R=13.924. The 2008-OT magnitude was rescaled accordingly.
(g) = Poor-quality night (clouds and poor seeing)
(h) = Additional UVOT detection limits: UVW1>19.85, UVW2>20.18, UVM2>19.44
(i) = Additional NIR detection limits were obtained with LT + SupIRCam:
J>18.07 and H>17.03
Note (5): Observations marked with the symbol "*" are unfiltered images, and
have all been rescaled to R-band magnitudes according to the prescriptions
of Pastorello et al. (2008MNRAS.389..955P 2008MNRAS.389..955P), with the only exception of the
observation from T. Tamura (January 4, 2001) which best matches V-band
magnitudes. The magnitude from T. Kryachko and S. Korotkiy's observation
(October 6, 2008) is from
http://www.astroalert.su/2008/10/09/possible-sn-in-ngc3432/
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 "YYYY/MMM/DD" Date Date of observations
13- 22 F10.2 --- JD Average Julian Date of observation
24 A1 --- l_umag Limit flag on umag
25- 29 F5.2 mag umag ? Sloan u band magnitude
31- 34 F4.2 mag e_umag ? rms uncertainty on umag
36- 40 F5.2 mag gmag ? Sloan g band magnitude
42- 45 F4.2 mag e_gmag ? rms uncertainty on gmag
47 A1 --- l_rmag Limit flag on rmag
48- 52 F5.2 mag rmag ? Sloan r band magnitude
54- 57 F4.2 mag e_rmag ? rms uncertainty on rmag
59 A1 --- l_imag Limit flag on imag
60- 64 F5.2 mag imag ? Sloan i band magnitude
66- 69 F4.2 mag e_imag ? rms uncertainty on imag
71 A1 --- l_zmag Limit flag on zmag
72- 76 F5.2 mag zmag ? Sloan z band magnitude
78- 81 F4.2 mag e_zmag ? rms uncertainty on zmag
83- 86 A4 --- Tel Telescope (1)
--------------------------------------------------------------------------------
Note (1): Telescopes as follows:
SDSS = 2.5-m Sloan Digital Sky Survey Telescope + TK2048E CCDs
(Apache Point Observatory, New Mexico, USA)
LT = 2.0-m Liverpool Telescope + RatCAM (La Palma, Canary Islands, Spain)
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 05-Aug-2013