J/PASP/122/1 BVRI light curves of SN 2007gi (Zhang+, 2010)
Optical observations of the rapidly expanding type Ia supernova 2007gi.
Zhang T., Wang X., Li W., Filippenko A.V., Wang L., Zhou X., Brown P.J.,
Silverman J.M., Steele T.N., Ganeshalingam M., Li J., Deng J., Li T.,
Qiu Y., Zhai M., Shang R.
<Publ. Astron. Soc. Pac., 122, 1-11 (2010)>
=2010PASP..122....1Z 2010PASP..122....1Z
ADC_Keywords: Supernovae ; Photometry, UBVRI
Abstract:
We present optical photometry and spectra for the Type Ia supernova
(SN Ia) 2007gi in the nearby galaxy NGC 4036. SN 2007gi is
characterized by extremely high-velocity (HV) features of the
intermediate-mass elements (Si, Ca, and S), with expansion velocities
(vexp) approaching 15500km/s near-maximum brightness (compared to
10600km/s for SNe Ia with normal vexp). SN 2007gi reached a B-band
peak magnitude of 13.25±0.04mag with a decline rate of
{DELTA}m15(B)(true)=1.33±0.09mag. The B-band light curve of SN 2007gi
demonstrated an interesting two-stage evolution during the nebular
phase, with a decay rate of 1.16±0.05mag/(100days) during
t=60-90days and 1.61±0.04mag/(100days) thereafter. Such behavior
was also observed in the HV SN Ia 2006X, and might be caused by the
interaction between supernova ejecta and circumstellar material (CSM)
around HV SNe Ia. Based on a sample of a dozen well-observed R band
(or unfiltered) light curves of SNe Ia, we confirm that the HV events
may have a faster rise time to maximum than those with normal vexp.
Description:
Photometry of SN 2007gi was obtained primarily with the 0.8m
Tsinghua-NAOC Telescope (TNT) located at NAOC Xinglong Observatory.
Observations of SN 2007gi began on 2007 August 8, 6 days before B-band
maximum, and continued for the next 6 months. SN 2007gi was also
observed during its early rising phase (from t~-11 to -7days)
with the Ultraviolet/Optical Telescope (UVOT) on board the Swift
Observatory.
Optical spectra of SN 2007gi were obtained primarily with the 3m
Shane telescope at Lick Observatory using the Kast double spectrograph.
A spectrum was also obtained on 2007 November 12 with the Low
Resolution Imaging Spectrometer (LRIS) mounted on the 10m Keck I
telescope on Mauna Kea, Hawaii.
Objects:
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RA (2000) DE Designation(s)
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12 01 23.4 +61 53 34 SN 2007gi = SN 2007gi
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 62 8 Magnitudes of photometric standards in the
SN 2007gi field
table2.dat 81 28 Optical photometry of SN 2007gi
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 I1 --- Seq Star sequential number
3- 8 F6.3 mag Vmag Johnson V magnitude
10- 14 F5.3 mag e_Vmag rms uncertainty on Vmag
16- 20 F5.3 mag B-V Johnson B-V colour index
22- 26 F5.3 mag e_B-V rms uncertainty on B-V
28- 32 F5.3 mag U-B Johnson U-B colour index
34- 38 F5.3 mag e_U-B rms uncertainty on U-B
40- 44 F5.3 mag V-Rc Johnson-Cousins V-Rc colour index
46- 50 F5.3 mag e_V-Rc rms uncertainty on V-Rc
52- 56 F5.3 mag V-Ic Johnson-Cousins V-Ic colour index
58- 62 F5.3 mag e_V-Ic rms uncertainty on V-Ic
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Date UT Date
12- 21 F10.2 d JD Julian date
23- 29 F7.2 d Phase Phase, relative to the epoch of B-band
maximum (JD 2454327.02)
31- 36 F6.3 mag Bmag Johnson B magnitude
38- 42 F5.3 mag e_Bmag rms uncertainty on Bmag
44- 49 F6.3 mag Vmag Johnson V magnitude
51- 55 F5.3 mag e_Vmag rms uncertainty on Vmag
57- 62 F6.3 mag Rcmag ?=- Cousins R magnitude
64- 68 F5.3 mag e_Rcmag ?=- rms uncertainty on Rmag
70- 75 F6.3 mag Icmag ?=- Cousins I magnitude
77- 81 F5.3 mag e_Icmag ?=- rms uncertainty on Imag
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 30-Mar-2010