J/AJ/105/2265 Spectroscopy and photometry of HD 212280 (Fekel+ 1993)
Chromospherically active stars. X. Spectroscopy and photometry of HD 212280
FEKEL F.C., BROWNING J.C., HENRY G.W., MORTON M.D., HALL D.S.
<Astron. J. 105, 2265 (1993)>
=1993AJ....105.2265F 1993AJ....105.2265F
Abstract:
The system HD 212280 is a chromospherically active double lined
spectroscopic binary with an orbital period of 45.284 days and an
eccentricity of 0.50. The spectrum is composite with spectral types of
G8 IV and F5-8 V for the components. An estimated inclination of 78
deg ± 8 deg results in masses of 1.7 and 1.4 solar masses for the G
subgiant and mid-F star, respectively. The distance to the system is
estimated to be 112 pc. Photometric observations obtained between 1987
November and 1992 June reveal that HD 212280 is a newly identified
variable star with a V amplitude of about 0.15 mag and a mean period of
29.46 days. Our V data were divided into 11 sets and in all but one
case two spots were required to fit the data. Lifetimes of 650 days
and a minimum of 1350 days have been determined for two of the four
spots. These lifetimes are consistent with the results of Hall & Busby
[Active Close Binaries, Proceedings of the NATO Advanced Studies Inst.
(Kluwer, Dordecht) (1990)]. The differential rotation coefficient of
0.05 is relatively small. Since the system has an eccentric orbit and
one component is significantly evolved, its evolutionary status is of
particular interest. The age of the system is about 1.9 x 10^9 years.
The G subgiant is rotating slower than pseudosynchronously while the
F-type star is rotating faster. The system and its components are
compared to the circularization and synchronization time scales of
Tassoul & Tassoul (ApJ, 395, 259, 1992).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1 67 32 Velocity observations of HD 212280
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See also:
V/76 : Chromospherically Active Binaries (Strassmeier+ 1993)
J/AJ/129/1669 : BV photometry of HD 37824, HD 181809, and HD 217188
(Fekel+, 2005)
Byte-by-byte Description of file: table1
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Bytes Format Units Label Explanations
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1- 11 F11.3 d HJD Heliocentric Julian Date of mid observation
12 A1 --- note [abc]'a' -- DDO observation
'b' -- Blended velocity, weight = 0.5
'c' -- central wavelength = 6700 A
15- 19 F5.3 --- Phase Phase of the observation with zero phase being
periastron passage
24- 28 F5.1 km/s Va Observed velocity of component A
33- 37 F5.1 km/s (O-C)a Residual to the fit or observed minus
calculated velocity of A
41- 45 F5.1 km/s Vb []? Observed velocity of component B
51- 54 F4.1 km/s (O-C)b []? Residual to the fit or observed minus
calculated velocity of B
59- 67 A9 --- Standard Name of the velocity standard star used to
determine the observed velocity of HD 212280.
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Origin: AAS CD-ROM series, Volume 1, 1993
References:
Fekel et al., Paper I 1985AJ.....90.2581F 1985AJ.....90.2581F
Fekel et al., Paper II 1986ApJS...60..551F 1986ApJS...60..551F
Fekel et al., Paper III 1987AJ.....94..726F 1987AJ.....94..726F
Fekel, Paper IV 1988AJ.....95..215F 1988AJ.....95..215F
Fekel et al., Paper V 1988AJ.....96.1426F 1988AJ.....96.1426F
Fekel et al., Paper VI 1989AJ.....97..202F 1989AJ.....97..202F
Fekel & Eitter, Paper VII 1989AJ.....97.1139F 1989AJ.....97.1139F
Fekel, Paper VIII 1991AJ....101.1489F 1991AJ....101.1489F
Fekel & Marschall, Paper XIX 1991AJ....102.1439F 1991AJ....102.1439F
Fekel et al., Paper XI 1993AJ....106.2370F 1993AJ....106.2370F
Fekel et al., Paper XII 1994AJ....108..694F 1994AJ....108..694F
Fekel et al., Paper XIII 1994AJ....108.1936F 1994AJ....108.1936F
Fekel et al., Paper XIV 1995AJ....109.2821F 1995AJ....109.2821F
Fekel, Paper XV 1996AJ....112..269F 1996AJ....112..269F
Fekel, Paper XVI 1997AJ....114.2747F 1997AJ....114.2747F
Fekel et al., Paper XVII 1998AJ....115.1153F 1998AJ....115.1153F
Fekel & Henry, Paper XVIII 2000AJ....120.3265F 2000AJ....120.3265F
Fekel et al., Paper XIX 2001AJ....122..991F 2001AJ....122..991F
Fekel et al., Paper XX 2001AJ....122.3447F 2001AJ....122.3447F
Fekel et al., Paper XXI 2002AJ....124.1064F 2002AJ....124.1064F
Fekel et al., Paper XXII 2004AJ....127.2303F 2004AJ....127.2303F
Fekel, Paper XXIII 2004AJ....127.2931F 2004AJ....127.2931F
Fekel & Henry, Paper XXIV 2005AJ....129.1669F 2005AJ....129.1669F, Cat. J/AJ/129/1669
Fekel et al., Paper XXV 2005AJ....130..794F 2005AJ....130..794F
(End) Patricia Bauer [CDS] 06-Jul-1994