J/AJ/144/187 Iris photometry near southern Cepheids. V. AQ Pup (Turner+, 2012)
A search for OB associations near southern long-period Cepheids.
V. AQ Puppis and V620 Puppis.
Turner D.G., van den Bergh S., Younger P.F., Majaess D.J., Pedreros M.H.,
Berdnikov L.N.
<Astron. J., 144, 187 (2012)>
=2012AJ....144..187T 2012AJ....144..187T
ADC_Keywords: Stars, variable ; Photometry, UBV ; Photometry, photographic
Keywords: open clusters and associations: general -
stars: fundamental parameters - stars: variables: Cepheids
Abstract:
A photometric UBV survey is presented for 610 stars in a region
surrounding the Cepheid AQ Puppis and centered southwest of the
variable, based upon photoelectric measures for 14 stars and
calibrated iris photometry of photographic plates of the field for 596
stars. An analysis of reddening and distance for program stars
indicates that the major dust complex in this direction is ∼1.8kpc
distant, producing differential extinction described by a ratio of
total-to-selective extinction of R=AV/EB-V=3.10±0.20. Zero-age
main-sequence fitting for the main group of B-type stars along the
line of sight yields a distance of 3.21±0.19kpc
(V0-MV=12.53±0.13s.e.). The 29.97 Cepheid AQ Pup, of field
reddening EB-V=0.47±0.07 (EB-V(B0)=0.51±0.07), appears to be
associated with B-type stars lying within 5' of it as well as with a
sparse group of stars, designated Turner 14, centered south of it at
J2000.0=07:58:37, -29:25:00, with a mean reddening of
EB-V=0.81±0.01. AQ Pup has an inferred luminosity as a cluster
member of <MV≥-5.40±0.25 and an evolutionary age of 3x107yr.
Its observed rate of period increase of +300.1±1.2s/yr is an order
of magnitude larger than what is observed for Cepheids of comparable
period in the third crossing of the instability strip, and may be
indicative of a high rate of mass loss or a putative fifth crossing.
Another sparse cluster, designated Turner 13, surrounds the newly
recognized 2.59 Cepheid V620 Pup, of space reddening
EB-V=0.64±0.02 (EB-V(B0)=0.68±0.02), distance 2.88±0.11kpc
(V0-MV=12.30±0.08s.e.), evolutionary age 108yr, and an
inferred luminosity as a likely cluster member of <MV≥-2.74±0.11.
V620 Pup is tentatively identified as a first crosser, pending
additional observations.
Description:
Photographic UBV photometry for 596 stars in the vicinity of AQ Pup
were obtained from iris photometry of plates in U, B, and V taken with
the 0.9m Swope telescope on Cerro Las Campanas in 1978 May and 1982
February (two plates in B and one plate in each of V and U). The iris
measures (with a precision of ±0.03mag) were obtained using the
Cuffey Iris Astrophotometer at Saint Mary's University. The resulting
photographic measures encompass a field of ∼18' radius centered on
J2000.0 coordinates 07:57:30.696, -29:17:54.79.
Objects:
-------------------------------------------------
RA (2000) DE Designation(s)
-------------------------------------------------
07 58 22.09 -29 07 48.3 AQ Puppis = HIP 38965
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 45 596 Photographic data for the AQ Pup field
table3.dat 42 79 Times of maximum light for AQ Pup
refs.dat 74 25 References
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See also:
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
II/285 : Photoelectric observations of Cepheids in UBV(RI)c (Berdnikov, 2008)
II/264 : ASAS Variable Stars in Southern hemisphere (Pojmanski+, 2002-2005)
J/MNRAS/434/2238 : Cepheids in open clusters (Anderson+, 2013)
J/A+A/534/A94 : Milky Way Cepheids radial velocities (Storm+, 2011)
J/MNRAS/389/1336 : Reddenings of FGK supergiants & Cepheids (Kovtyukh+, 2008)
J/AJ/130/1194 : UBV photometry of Ruprecht 91 (Turner+, 2005)
J/A+A/404/423 : BVI photometry of Galactic Cepheids (Tammann+, 2003)
J/ApJS/137/209 : BVI observations of southern Cepheids (Berdnikov+, 2001)
J/A+AS/143/211 : Galactic Cepheids BVRI photometry (Berdnikov+, 2000)
J/A+A/314/541 : Long period Cepheids (Antonello+, 1996)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Hour of Right Ascension (J2000)
4- 5 I2 min RAm Minute of Right Ascension (J2000)
7- 12 F6.3 s RAs Second of Right Ascension (J2000)
14 A1 --- DE- Sign of the Declination (J2000)
15- 16 I2 deg DEd Degree of Declination (J2000)
18- 19 I2 arcmin DEm Arcminute of Declination (J2000)
21- 25 F5.2 arcsec DEs Arcsecond of Declination (J2000)
27- 31 F5.2 mag Vmag Photographic V magnitude (1)
33- 36 F4.2 mag B-V The (B-V) photographic color index (1)
38- 42 F5.2 mag U-B The (U-B) photographic color index (1)
44- 45 A2 --- Comp D=double, FC=faint companion, TC=two companions
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Note (1): From iris photometry.
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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- 11 F11.3 d HJDmax Heliocentric Julian Date of light maximum (1)
13- 17 F5.3 d e_HJDmax 1σ error in HJDmax
19- 20 A2 --- Meth Detection method (PG=photographic,
B=photoelectric B, V=photoelectric V)
22- 25 I4 --- E Epoch (number of elapsed cycles)
27- 32 F6.3 d O-C The O-C value
34- 36 I3 --- N Number of observations used to establish the
observed light maxima
38- 42 A5 --- Ref Reference of observation; in refs.dat file
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Note (1): Derived from the complete light curves using Hertzsprung's method
(Berdnikov, 1992SvAL...18..207B 1992SvAL...18..207B).
HJDmax=2433687.1920(±0.1397)+29.9726(±0.0002)E+142.49(±0.56)*10-6E2
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Ref Reference identifier
7- 25 A19 --- BibCode Bibliographic code
27- 53 A27 --- Aut Author's name
55- 74 A20 --- Com Comments
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History:
From electronic version of the journal
References:
van den Bergh et al, Paper I, 1982ApJS...50..529V 1982ApJS...50..529V
van den Bergh et al, Paper II, 1983ApJS...53..765V 1983ApJS...53..765V
van den Bergh et al, Paper III, 1985ApJS...57..743V 1985ApJS...57..743V
Turner et al, Paper IV, 1993ApJS...85..119T 1993ApJS...85..119T
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 13-Jan-2014