J/AJ/133/665 Photometry of type II Cepheid candidates (Schmidt+, 2007)
Photometry of type II Cepheid candidates from the ROTSE-I demonstration project.
Schmidt E.G., Langan S., Rogalla D., Thacker-Lynn L.
<Astron. J., 133, 665-675 (2007)>
=2007AJ....133..665S 2007AJ....133..665S
ADC_Keywords: Stars, variable ; Photometry
Keywords: Cepheids - stars: Population II
Abstract:
We have obtained VR photometry of 205 Cepheid variable star candidates
that were discovered in a small section of the Northern Sky
Variability Survey. Given their locations and apparent magnitudes, any
stars in this sample that are Cepheids are very likely to be type II
Cepheids. On the basis of the regularity of variation, revised
periods, light-curve morphology, slope of the color-magnitude
relation, and color, we have identified 97 probable Cepheids and 17
possible Cepheids. While some of the photometric properties,
particularly the colors, are consistent with the identification of
these stars as Cepheids, the amplitudes are small compared to known
type II Cepheids and the period distribution does not match that of
known type II Cepheids.
Description:
The new observations reported here consist of 3383 VR photometric
observations made between 2003 September and 2006 May
(JD 2452899-2453888) at Behlen Observatory.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 66 205 Program stars
table2.dat 29 3383 Photometric data
table3.dat 65 205 Light curve parameters
notes.dat 80 20 Individual notes
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See also:
II/250 : Combined General Catalogue of Variable Stars (Samus+ 2004)
J/AJ/119/1901 : ROTSE all-sky surveys for variable stars (Akerlof+, 2000)
ftp://skydot.lanl.gov/pub/projects/skydot/nsvs/ : NSVS database
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Seq Running object number, RNNN
6- 24 A19 --- Rotse1 Star Name (JHHMMSS.ss+DDMMSS.s)
26- 34 A9 --- GCVS Name from GCVS
36- 47 F12.8 d PerA Period from Akerlof et al.
(2000, Cat. J/AJ/119/1901)
49- 53 F5.2 mag mag Mean unfiltered ROTSE magnitude from Akerlof
et al. (2000, Cat. J/AJ/119/1901)
55- 59 F5.3 mag Amp ? Amplitude from Akerlof et al.
(2000, Cat. J/AJ/119/1901)
61- 62 I2 --- NB Number of Observations from Behlen Observatory
64- 66 I3 --- NSV Number of Observations from the NSVS
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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- 4 A4 --- Seq Running Object Number, RNNN
6- 16 F11.3 d HJD Heliocentric Julian date
18- 23 F6.3 mag Vmag The V band magnitude
25- 29 F5.3 mag V-R The (V-R) color index
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Seq Running Object Number, RNNN
5 A1 --- n_Seq [*] indicates a note in notes.dat file
7- 16 F10.6 d Per ? Period From Present Study (2)
17 A1 --- f_Per [c] no period found (3)
19- 20 I2 0.01d e_Per ? Uncertainty in Period
22- 26 F5.2 mag <Vmag> Mean V magnitude
27 A1 --- f_<Vmag> [c] Arithmetic mean (4)
29- 30 I2 mag e_<Vmag> ? Uncertainty in <Vmag>
32- 36 F5.2 mag <V-R> Mean V-R color index
37 A1 --- f_<V-R> [c] Arithmetic mean (4)
39- 40 I2 mag e_<V-R> ? Uncertainty in <V-R>
42- 45 F4.2 mag Vamp The V Amplitude
46 A1 --- f_Vamp [c] Vamp is a range (5)
48- 52 F5.2 --- Slope ? Slope of V/V-R Relation
54- 57 F4.2 --- e_Slope ? Uncertainty in Slope
59- 63 A5 --- n_St Rejection status (6)
65 A1 --- St [AB ] Status of Star as Cepheid Candidate (7)
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Note (2): The period was determined using only the present photometry for
the following stars: R032, R034, R038, R043, R053, R063, R070, R080,
R094, R096, R099, R106, R113, R131, R139, R154, R155, R157, R160,
R161, R165, R173, R176, R177, R179, R188.
Note (3): 'c' means that a defined value could not be found, but a
characteristic value could be discerned.
Note (4): 'c' means that the magnitude or color listed is an arithmetic
mean of all the measured magnitudes or colors.
Note (5): 'c' means that the amplitude could not be measured so the range
of all the measured magnitudes is listed.
Note (6): The codes indicate reasons for rejecting the star as a Cepheid
candidate are as follows:
BL = too blue to be a Cepheid
CO = constant star
CV = light curve indicates a cataclysmic variable
EC = light curve indicates an eclipsing binary
IR = irregularity of the period or light curve eliminates the star
as a Cepheid
RE = too red to be a Cepheid
SL = the slope of the color-magnitude relation falls outside of
the expected range for a Cepheid
SP = period too short for a Cepheid
Note (7): 'A' indicates a probable Cepheid, and 'B' a possible Cepheid.
A blank entry indicates that the star was rejected as discussed
in the text.
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Byte-by-byte Description of file: notes.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Seq Running object number, RNNN
6- 80 A75 --- Note Text of the note
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History:
From electronic version of the journal
References:
Schmidt et al., Paper II, 2009AJ....137.4598S 2009AJ....137.4598S, Cat. J/AJ/137/4598
Schmidt et al., Paper III, 2011AJ....141...53S 2011AJ....141...53S, Cat. J/AJ/141/53
Schmidt et al., Paper IV, 2013AJ....146...61S 2013AJ....146...61S, Cat. J/AJ/146/61
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 12-Dec-2008