J/ApJ/522/802 Cepheid calibration of SN 1989B in NGC 3627 (Saha+, 1999)
Cepheid calibration of the peak brightness of type Ia supernovae. IX. SN1989B
in NGC 3627
Saha A., Sandage A., Tammann G.A., Labhardt L., Macchetto F.D., Panagia N.
<Astrophys. J. 522, 802 (1999)>
=1999ApJ...522..802S 1999ApJ...522..802S
ADC_Keywords: Photometry ; Stars, variable ; Supernovae
Mission_Name: HST
Keywords: Cepheids - distance scale - galaxies: individual
(NGC 3627) - supernovae: individual (SN 1989B)
Abstract:
Repeated imaging observations have been made of NGC 3627 with the
Hubble Space Telescope in 1997 - 1998 over an interval of 58 days.
Images were obtained on 12 epochs in the F555W band and on five epochs
in the F814W band. The galaxy hosted the prototypical, "Branch
normal," type Ia supernova SN 1989B. A total of 83 variables have been
found, of which 68 are definite Cepheid variables with periods ranging
from 75 to 3.85 days. The dereddened distance modulus is determined to
be (m-M)o=30.22±0.12 (internal uncertainty) using a subset of
the Cepheid data whose reddening and error parameters are secure.
Objects:
---------------------------------------------------
RA (2000) DE Designation(s)
---------------------------------------------------
11 20 15.09 +12 59 29.4 NGC 3627 = M 66 = UGC 6346
---------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 27 84 Positions of the variable stars on the chip
table3.dat 34 1411 Photometry of the variable stars
table4.dat 65 68 Cepheid characteristics
--------------------------------------------------------------------------------
See also:
II/189 : Magnitude Observations of Type I Supernovae (Cadonau+ 1990)
J/AJ/112/2408 : Light Curves of 29 SNe (Hamuy+ 1996)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- Name Cepheid name
11- 15 F5.1 pix Xpix X pixel coordinate
21- 25 F5.1 pix Ypix Y pixel coordinate
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- Name Cepheid name
9- 19 F11.4 d JD Julian Date of observation
22- 26 F5.2 mag Mag ? Observed magnitude
28- 31 F4.2 mag e_Mag ? Uncertainty in Mag
34 A1 --- f_Mag [VI] Indicates Mag is a V band (V) or
an I band (I) observation
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- Name Cepheid name
11- 14 F4.1 d Period Cepheid period
16- 20 F5.2 mag Vmag Mean V band magnitude
22- 25 F4.2 mag e_Vmag Uncertainty in Vmag
27- 31 F5.2 mag Imag Mean I band magnitude
33- 36 F4.2 mag e_Imag Uncertainty in Imag
38- 43 F6.3 mag (m-M)v Apparent V band distance moduli
45- 50 F6.3 mag (m-M)I Apparent I band distance moduli
52- 57 F6.3 mag m-M True apparent distance moduli
59- 63 F5.3 mag e_m-M Uncertainty in Ut
65 I1 --- q_Name [0,6] Quality index of the light-curve (1)
--------------------------------------------------------------------------------
Note (1): The light-curve quality index ranges from 0 - 6. In
this scheme, two points are given for the quality of the F555W light
curves, two points for the evenness in phase coverage of the five
F814W observation epochs, and three points for the amplitude and phase
coherence of the F814W observations compared with the F555W light
curve. Hence a quality index of 6 indicates the best possible
light-curve quality. A quality index of 2 or less indicates near-fatal
flaws such as apparent phase incoherence in the two passbands. This is
generally the indication that object confusion by crowding and/or
contamination by background is likely.
--------------------------------------------------------------------------------
History:
From the ApJ Electronic edition
References:
(Paper I) Sandage+ (1996ApJ...460L..15S 1996ApJ...460L..15S)
(Paper V) Saha+ (1996ApJ...466...55S 1996ApJ...466...55S)
(Paper VI) Saha+ (1996ApJS..107..693S 1996ApJS..107..693S)
(Paper VIII) Saha+ (1997ApJ...486....1S 1997ApJ...486....1S)
(End) Greg Schwarz [AAS] 10-Mar-2000