J/MNRAS/434/870 Radial velocity curves of 3 Cepheids (Szabados+, 2013)
Discovery of the spectroscopic binary nature of three bright southern Cepheids.
Szabados L., Anderson R.I., Derekas A., Kiss L.L., Szalai T., Szekely P.,
Christiansen J.L.
<Mon. Not. R. Astron. Soc., 434, 870-877 (2013)>
=2013MNRAS.434..870S 2013MNRAS.434..870S
ADC_Keywords: Stars, variable ; Radial velocities
Keywords: binaries: spectroscopic - stars: variables: Cepheids
Abstract:
We present an analysis of spectroscopic radial velocity and
photometric data of three bright Galactic Cepheids: LR Trianguli
Australis (LR TrA), RZ Velorum (RZ Vel) and BG Velorum (BG Vel). Based
on new radial velocity data, these Cepheids have been found to be
members of spectroscopic binary systems. The ratio of the peak-to-peak
radial velocity amplitude to photometric amplitude indicates the
presence of a companion for LR TrA and BG Vel. IUE spectra
indicate that the companions of RZ Vel and BG Vel cannot be hot stars.
The analysis of all available photometric data revealed that the
pulsation period of RZ Vel and BG Vel varies monotonically, due to
stellar evolution. Moreover, the longest period Cepheid in this
sample, RZ Vel, shows period fluctuations superimposed on the
monotonic period increase. The light-time effect interpretation of the
observed pattern needs long-term photometric monitoring of this
Cepheid. The pulsation period of LR TrA has remained constant since
the discovery of its brightness variation. Using statistical data, it
is also shown that a large number of spectroscopic binaries still
remain to be discovered among bright classical Cepheids.
Description:
We performed an RV survey of Cepheids with the 2.3-m ANU telescope
located at the Siding Spring Observatory (SSO), Australia.
In 64 nights between 2004 October and 2006 March we monitored 40
Cepheids with pulsation periods between 2 and 30d. Additional
spectra of some targets were obtained in 2007 August.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 66 3 Basic data of the programme stars
table3.dat 16 10 RV values of LR TrA from Siding Spring Obs. spectra
table4.dat 23 32 CORALIE velocities of LR TrA
table7.dat 16 30 RV values of RZ Vel from Siding Spring Obs. spectra
table8.dat 23 67 CORALIE velocities of RZ Vel
table11.dat 16 27 RV values of BG Vel from Siding Spring Obs. spectra
table12.dat 23 33 CORALIE velocities of BG Vel
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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- 6 A6 --- Name Star name
8- 9 I2 h RAh Right ascension (J2000)
11- 12 I2 min RAm Right ascension (J2000)
14- 18 F5.2 s RAs Right ascension (J2000)
20 A1 --- DE- Declination sign (J2000)
21- 22 I2 deg DEd Declination (J2000)
24- 25 I2 arcmin DEm Declination (J2000)
27- 30 F4.1 arcsec DEs Declination (J2000)
32- 35 F4.2 mag <Vmag> Mean V magnitude
37- 45 F9.6 d Per Period
47- 60 A14 --- Puls Mode of pulsation (Fundamental/First overtone)
62- 63 I2 --- NSSO [10/30] Number of SSO spectra
65- 66 I2 --- NCor [32/67] Number of Coralie spectra
68- 69 I2 --- TSSO [3/11] Table number of SSO spectra
71- 72 I2 --- TCor [4/12] Table number of Coralie spectra
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Byte-by-byte Description of file: table3.dat table7.dat table11.dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 d HJD Heliocentric Julian date (HJD-2400000)
12- 16 F5.1 km/s RV Radial velocity
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Byte-by-byte Description of file: table4.dat table8.dat table12.dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 d HJD Heliocentric Julian date (HJD-2400000)
12- 17 F6.2 km/s RV Radial velocity
20- 23 F4.2 km/s e_RV Velocity dispersion
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 12-Jan-2015