J/A+A/690/A284 VELOCE II. spectroscopic binary Cepheids (Shetye+, 2024)
VELOcities of CEpheids (VELOCE).
II. Systematic search for spectroscopic binary Cepheids.
Shetye S.S., Viviani G., Anderson R.I., Mowlavi N., Eyer L., Evans N.R.,
Szabados L.
<Astron. Astrophys. 690, A284 (2024)>
=2024A&A...690A.284S 2024A&A...690A.284S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Binaries, spectroscopic ; Binaries, orbits
Keywords: binaries: general - binaries: spectroscopic - stars: oscillations -
stars: variables: Cepheids
Abstract:
Classical Cepheids provide valuable insights into the evolution of
stellar multiplicity among intermediate-mass stars. Here, we present a
systematic investigation of single-lined spectroscopic binaries (SB1s)
based on high-precision velocities measured by the VELOcities of
CEpheids (VELOCE) project. We detected 76 (29%) SB1 systems among the
258 Milky Way Cepheids in the first VELOCE data release, 32 (43%) of
which were not previously known to be SB1 systems. We determined 30
precise and three tentative orbital solutions, 18 (53%) of which are
reported for the first time. This large set of Cepheid orbits provides
a detailed view of the eccentricity e and orbital period Porb
distribution among evolved intermediate-mass stars, ranging from
e∈[0.0,0.8] and Porb∈[240,9000] d. The orbital motion on
timescales exceeding the 11yr VELOCE baseline was investigated using a
template-fitting technique applied to literature data. Particularly
interesting objects include (a) R Cru, the Cepheid with the shortest
orbital period in the Milky Way (∼238d); (b) ASAS J103158-5814.7, a
short-period overtone Cepheid exhibiting time-dependent pulsation
amplitudes as well as orbital motion; and (c) 17 triple systems with
outer visual companions, among other interesting objects. Most VELOCE
Cepheids (21/23) that exhibit evidence of a companion based on a Gaia
proper motion anomaly are also spectroscopic binaries, whereas the
remaining do not exhibit significant (>3σ) orbital radial
velocity variations. Gaia quality flags, notably the renormalized unit
weight error (RUWE), do not allow Cepheid binaries to be identified
reliably although statistically the average RUWE of SB1 Cepheids is
slightly higher than that of non-SB1 Cepheids. A comparison with Gaia
photometric amplitudes in G-, Bp, and Rp also does not allow one to
identify spectroscopic binaries among the full VELOCE sample,
indicating that the photometric amplitudes in this wavelength range
are not sufficiently informative of companion stars.
Description:
We have presented the largest homogeneous investigation of 76 SB1
Cepheids to date based on the unprecedented RV data set provided by
the VELOCE project (Paper I, Anderson et al., 2024A&A...686A.177A 2024A&A...686A.177A,
Cat. J/A+A/686/A177). An additional 14 SB1 candidates have been
identified in Paper I, but are not discussed here due to their nature
as candidate binaries. VELOCE data allow us to extend the search for
binary Cepheids to fainter magnitudes, adding 32 new SB1 systems, and
18 first orbital determinations of Cepheids, 11 of which are fainter
than mV>8mag.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 95 100 Sample of binary Cepheids and candidates from
the literature considered here
table2.dat 143 23 Orbital elements of the new spectroscopic binary
Cepheids' orbits presented in this work
table3.dat 143 24 Orbital elements of VELOCE SB1 Cepheids with
literature-known orbits
table4.dat 39 30 List of SB1 from our sample where we found some
evidence of orbital motion, and a polynomial
was fitted as the orbit could not be sampled
or covered adequately
table5.dat 30 75 Gaia astrometry and PMa tags for the confirmed
SB1 Cepheids within VELOCE
ExtraData-2.pdf 512 6866 Supplementary data file
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See also:
J/A+A/686/A177 : VELOCE I. Cepheids High-precision RVs (Anderson+, 2024)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Set [ABCD] Set (1)
3- 21 A19 --- Cepheid Cepheid name (from Simbad)
23- 41 I19 --- GaiaDR3 ? Gaia DR3 source ID (from Simbad)
43- 47 F5.2 mag Vmag ?=- V magnitude (from Simbad)
50- 54 F5.2 mag Gmag ?=- G magnitude (from Simbad)
56- 62 F7.4 d Ppuls Pulsation period from Paper I
64- 69 A6 --- Status Status (2)
70- 83 A14 --- Ref References (3)
85- 92 A8 --- Evid Evidence (4)
93 A1 ---- n_Evid [1] Note on Evid (5)
95 A1 --- Triple? [Y] indicates whether the star is likely part
of a triple system, usually involving a
visually resolved companion.
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Note (1): Sets as follows:
A = Newly discovered spectroscopic binary Cepheids
B = First orbital solutions for literature SB1 Cepheids
C = Literature SB1 confirmed by VELOCE
D = Literature SB1 not confirmed by VELOCE
Note (2): Status as follows:
New = star's SB1 nature was newly discovered
Known = star's SB1 nature previously known
Susp = star's SB1 nature previously suspected.
Stars listed as Susp among newly discovered SB1 systems were
considered tentative previously
Note (3): References as follows:
R1 = Evans & Udalski (1994AJ....108..653E 1994AJ....108..653E)
R2 = Evans (1994ApJ...436..273E 1994ApJ...436..273E)
R3 = Lloyd Evans (1982MNRAS.199..925L 1982MNRAS.199..925L)
R4 = Petterson et al. (2004MNRAS.350...95P 2004MNRAS.350...95P)
R5 = Kovtyukh et al. (2015MNRAS.448.3567K 2015MNRAS.448.3567K)
R6 = Anderson (2013, PhD thesis, Universite de Geneve)
R7 = Szabados (2003IBVS.5394....1S 2003IBVS.5394....1S)
R8 = Szabados & Pont (1998A&AS..133...51S 1998A&AS..133...51S)
R9 = Szabados et al. (2013MNRAS.430.2018S 2013MNRAS.430.2018S, Cat. J/MNRAS/430/2018)
R10 = Anderson et al. (2016ApJS..226...18A 2016ApJS..226...18A, Cat. J/ApJS/226/18)
R11 = Griffin (2016Obs...136..209G 2016Obs...136..209G)
R12 = Anderson et al. (2015ApJ...804..144A 2015ApJ...804..144A, Cat. J/ApJ/804/144)
R13 = Evans (1995ApJ...445..393E 1995ApJ...445..393E)
R14 = Bersier et al. (1994A&AS..108...25B 1994A&AS..108...25B, cat. J/A+AS/108/25)
R15 = Evans (1991ApJ...372..597E 1991ApJ...372..597E)
R16 = Gallenne et al. (2019A&A...622A.164G 2019A&A...622A.164G, Cat. J/A+A/622/A164)
R17 = Szabados (1996A&A...311..189S 1996A&A...311..189S)
R18 = Evans et al. (1990PASP..102..981E 1990PASP..102..981E)
R19 = Evans (1992ApJ...384..220E 1992ApJ...384..220E)
R20 = Gorynya et al. (1996PAZh...22...38G 1996PAZh...22...38G)
R21 = Wahlgren & Evans (1998A&A...332L..33W 1998A&A...332L..33W)
R22 = Pont et al. (1994A&A...285..415P 1994A&A...285..415P)
R23 = Gallenne et al. (2013A&A...552A..21G 2013A&A...552A..21G)
R24 = Szabados (1992Obs...112...57S 1992Obs...112...57S)
R25 = Madore (1977MNRAS.178..505M 1977MNRAS.178..505M)
R26 = Gieren (1982ApJS...49....1G 1982ApJS...49....1G)
R27 = Szabados et al. (2014MNRAS.442.3155S 2014MNRAS.442.3155S)
R28 = Turner et al. (2007PASP..119.1247T 2007PASP..119.1247T)
R29 = Russo et al. (1981A&A...102...20R 1981A&A...102...20R)
R30 = Bersier (2002ApJS..140..465B 2002ApJS..140..465B)
R31 = Szabados et al. (2013MNRAS.434..870S 2013MNRAS.434..870S, Cat. J/MNRAS/434/870)
R32 = Anderson (2019A&A...623A.146A 2019A&A...623A.146A, Cat. J/A+A/623/A146)
R33 = Gorynya et al. (1996PAZh...22..198G 1996PAZh...22..198G).
VELOCE = cases where VELOCE data was previously used to establish the
binarity or the orbit.
Note (5): 1 We refer the reader to Anderson (2019A&A...623A.146A 2019A&A...623A.146A) for the
detailed orbital solution of alpha UMi using VELOCE data.
Note (4): states whether we determine a combined model for orbit and pulsation
(Orbit), determine a trend in the pulsation residuals (Trend), or whether
template fitting involving literature RV data indicates a time-variable
vgamma, (RVTF-Yes) or not (RVTF-No).
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Byte-by-byte Description of file: table2.dat table3.dat
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Bytes Format Units Label Explanations
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1 A1 --- Set [ABCD] Set (1)
3- 21 A19 --- Cepheid Cepheid name
23- 29 F7.4 d Ppuls ? Pulsation period (2)
31- 38 F8.2 d T0 Time of minima (JD-2400000) (2)
40- 42 A3 --- data Type of data (3)
44- 50 F7.2 d Porb Orbital period
52- 56 F5.3 --- e ? Eccentricity
58- 63 F6.3 km/s K Radial velocity semi-amplitude
65- 70 F6.4 au asini Projected semi-major axis
72- 77 E6.2 --- fmass Mass function
79- 84 F6.2 deg omega ? Argument of periastron
86- 88 F3.1 Msun M1 ? Cepheid mass (4)
90- 93 F4.2 km/s rms Root mean square of the fit between the
Fourier+Keplerian model and the RV data
for V orbits and between the keplerian model
and epoch residuals for V+L orbits
95-100 F6.2 d e_T0 Time of minima error
102-103 I2 --- Fig Orbital figure number in ExtraData-2.pdf file
105-110 F6.2 d e_Porb Orbital period error
112-116 F5.3 --- e_e ? Eccentriciy error
118-122 F5.3 km/s e_K Radial velocity semi-amplitude error
124-129 F6.4 au e_asini Projected semi-major axis error
131-136 E6.2 --- e_fmass Mass function error
138-143 F6.2 deg e_omega ? Argument of periastron error
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Note (1): Set as follows:
A = New orbits from current work (in table 2)
B = New-Tentative-orbits from current work (in table 2)
C = Update to literature-known SB1s orbit (in table 2)
D = Update to literature-known SB1s orbits (in table 3)
Note (2): The pulsation period and epoch are retrieved after the RV fitting
following the method described in Paper 1 (Anderson et al.,
2024A&A...686A.177A 2024A&A...686A.177A, Cat. J/A+A/686/A177).
Note (3): Type of data as follows:
V = when the orbits were strictly fitted with VELOCE data alone
V+L = when the orbit was fitted using the combination of v residuals from
VELOCE and literature datasets
(See Section 3.2 of the main article for more details about the methods).
Note (4): We estimated the individual Cepheid masses using period-mass relations
based on Geneva stellar evolution models (Ekstrom et al., 2012A&A...537A.146E 2012A&A...537A.146E,
Cat. J/A+A/537/A146), our method was similar to the one described in
Anderson et al. (2016MNRAS.463.1707A 2016MNRAS.463.1707A, Cat. J/MNRAS/463/1707).
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Set [AB] Set (1)
3- 21 A19 --- Cepheid Cepheid name
23 I1 --- deg Degree of polynomial used in our analysis
25- 29 F5.2 km/s A2p2 Peak-to-peak amplitude of the (linear or
nonlinear) v variation
31- 34 I4 d DeltaT2p2 Timeline over which this amplitude was
computed
36- 39 A4 --- Trend Direction of the trend, up for increasing
velocity, down for decreasing
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Note (1): Set as follows:
A = SB1s discovered in the current work
B = Literature-known SB1s
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Set [ABC] Set (1)
3- 21 A19 --- Cepheid Cepheid name
23- 28 F6.4 --- RUWE ? Gaia RUWE
30 I1 --- Binflag [0/1]? Binflag Star from PMa (2)
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Note (1): Set as follows:
A = SB1 with Orbits
B = SB1 with Trends
C = SB1 with RVTF-Yes
Note (2): Binary flag as follows:
1 = star was flagged as binary through PMa
0 = PMa did not detect it as binary
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History:
From electronic version of the journal, https://zenodo.org/records/12818503
References:
Anderson et al., 2024A&A...686A.177A 2024A&A...686A.177A, Cat. J/A+A/686/A177
(End) Patricia Vannier [CDS] 21-Mar-2025