J/MNRAS/485/3457 Rotational modulation in TESS B stars (Balona+, 2019)
Rotational modulation in TESS B stars.
Balona L.A., Handler G., Chowdhury S., Ozuyar D., Engelbrecht C.A.,
Mirouh G.M., Wade G.A., David-Uraz A., Cantiello M.
<Mon. Not. R. Astron. Soc., 485, 3457-3469 (2019)>
=2019MNRAS.485.3457B 2019MNRAS.485.3457B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, early-type ; Stars, B-type ; Stars, variable ;
Rotational velocities ; Effective temperatures ; Optical
Keywords: stars: early-type - stars: oscillations - stars: rotation
Abstract:
Light curves and periodograms of 160 B stars observed by the
Transiting Exoplanet Survey Satellite (TESS) space mission and 29
main-sequence B stars from Kepler and K2 were used to classify the
variability type. There are 114 main-sequence B stars in the TESS
sample, of which 45 are classified as possible rotational variables.
This confirms previous findings that a large fraction (about 40 per
cent) of A and B stars may exhibit rotational modulation. Gaia DR2
parallaxes were used to estimate luminosities, from which the radii
and equatorial rotational velocities can be deduced. It is shown that
observed values of the projected rotational velocities are lower than
the estimated equatorial velocities for nearly all the stars, as they
should be if rotation is the cause of the light variation. We conclude
that a large fraction of main-sequence B stars appear to contain
surface features which cannot likely be attributed to abundance
patches.
Description:
TESS observes the sky in sectors measuring 24°x96° that extend
from near the ecliptic equator to beyond the ecliptic pole. Each
sector is observed for two orbits of the satellite around the Earth,
or about 27d.
The data analysed in this paper are from the light curves of the first
release (Sectors 1 and 2). Most of the stars discussed here are at
mid-latitudes and have been observed for a time span of about 55d. A
description of how these data products were generated is found in
Jenkins et al. (2016SPIE.9913E..3EJ).
The TESS input catalogue (Stassun et al. 2018AJ....156..102S 2018AJ....156..102S, Cat.
J/AJ/156/102) lists stellar parameters for stars observed by TESS. The
effective temperatures, Teff, for stars without spectroscopic
determinations were obtained from near-infrared photometry, which is
not reliable for B stars, particularly since reddening is important in
many cases. The stars observed by TESS were matched with the SIMBAD
astronomical data base (Wenger et al. 2000A&AS..143....9W 2000A&AS..143....9W) and only
those known to be B stars were selected, giving a total of 160 stars
with spectral types earlier than A0 (see Table 1).
In addition to the TESS stars, we have examined the light curves of
Kepler (Kepler Mission Team, 2009yCat.5133....0K 2009yCat.5133....0K, Cat. V/133) and K2
(Huber et al. 2017yCat.4034....0H 2017yCat.4034....0H, Cat. IV/34) data for possible
rotational modulation. The Kepler data have a time span of nearly 4yr
which results in a very low periodogram noise level. The K2 data have
a time span of around 80d. Table 3 lists the measurements and stellar
parameters obtained for Kepler and K2 light curves.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 109 160 List of B stars observed by TESS
table3.dat 108 29 Additional rotational variables identified from
the light curves of the Kepler and K2 missions
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See also:
J/AJ/156/102 : The TESS Input Catalog and Candidate Target List
(Stassun+, 2018)
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 I9 --- Name TIC star name (NNNNNNNNN)
11- 25 A15 --- OName Other name
27- 40 A14 --- VarType Assigned variability type (GCVS type in
parenthesis from Samus et al.
2017ARep...61...80S 2017ARep...61...80S, Cat. B/gcvs)
42- 47 F6.3 mag Vmag Apparent V magnitude
49- 53 F5.3 d-1 nurot ? Presumed rotational frequency (in cycles/d)
55- 59 I5 ppm Arot ? Amplitude of the periodogram peak
61- 63 I3 --- S/N ? Signal to noise ratio of the periodogram
peak
65 I1 --- NH ? Number of visible harmonics
67- 69 I3 km/s ve ? Derived equatorial rotational velocity (G1)
71- 73 I3 km/s vsini ? Projected rotational velocity from the
literature
75- 79 I5 K Teff ? Adopted effective temperature
81- 82 I2 --- r_Teff ? Reference for Teff (G2)
84- 88 F5.2 [Lsun] logLstar ? Stellar luminosity obtained from the Gaia
parallax (Gaia Collaboration
2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345)
90-109 A20 --- SpType Spectral type ((Be) indicates classical Be
star)
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- Name Star name from KIC/EPIC
16- 27 A12 --- OName Other name
29- 39 A11 --- VarType Assigned variability type (GCVS type in
parenthesis from Samus et al.
2017ARep...61...80S 2017ARep...61...80S, Cat. B/gcvs)
41- 46 F6.3 mag Vmag Apparent V magnitude
48- 52 F5.3 d-1 nurot Presumed rotational frequency (in cycles/d)
54- 58 I5 ppm Arot Amplitude of the periodogram peak
60- 61 I2 --- S/N Signal to noise ratio of the periodogram peak
63 I1 --- NH Number of visible harmonics
65- 67 I3 km/s ve Derived equatorial rotational velocity (G1)
69- 71 I3 km/s vsini Projected rotational velocity from the
literature
73- 77 I5 K Teff Adopted effective temperature
79- 80 I2 --- r_Teff Reference for Teff (G2)
82- 85 F4.2 [Lsun] logLstar Stellar luminosity obtained from the Gaia
parallax (Gaia Collaboration
2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345)
87-108 A22 --- SpType Spectral type ((Be) indicates classical Be
star)
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Global Notes:
Note (G1): The equatorial rotational velocity is given by
ve=50.74nurot(R/R☉)
Note (G2): References as follows:
1 = Pecaut & Mamajek (2013ApJS..208....9P 2013ApJS..208....9P, Cat. J/ApJS/208/9) Spectral type
2 = Urbaneja et al. (2017AJ....154..102U 2017AJ....154..102U, Cat. J/AJ/154/102) Spectroscopy
3 = Gianninas, Bergeron & Ruiz (2011ApJ...743..138G 2011ApJ...743..138G, Cat. J/ApJ/743/138)
Spectroscopy
4 = Paunzen, Schnell & Maitzen (2005A&A...444..941P 2005A&A...444..941P, Cat. J/A+A/444/941)
Narrow-band photometry
5 = Wright et al. (2003AJ....125..359W 2003AJ....125..359W, Cat. III/231) Spectral type
6 = Balona (1994MNRAS.268..119B 1994MNRAS.268..119B) Stromgren
7 = Chandler, McDonald & Kane (2016AJ....151...59C 2016AJ....151...59C, Cat. J/AJ/151/59)
SED fitting
8 = Gullikson, Kraus & Dodson-Robinson (2016AJ....152...40G 2016AJ....152...40G,
Cat. J/AJ/152/40 ) Spectroscopy
9 = Sanchez-Blazquez et al. (2006MNRAS.371..703S 2006MNRAS.371..703S, Cat. J/MNRAS/371/703)
Spectroscopy
10 = McDonald, Zijlstra & Watson (2017MNRAS.471..770M 2017MNRAS.471..770M, Cat. J/MNRAS/471/770)
SED fitting
11 = Geier et al. (2017A&A...600A..50G 2017A&A...600A..50G, Cat. J/A+A/600/A50) Stectral type/SED
12 = Oey & Massey (1995ApJ...452..210O 1995ApJ...452..210O, Cat. J/ApJ/452/210) Sp.Type and UBV
13 = Paunzen et al. (2013MNRAS.429..119P 2013MNRAS.429..119P, Cat. J/MNRAS/429/119)
UBV/Geneva/Stromgren
14 = David & Hillenbrand (2015ApJ...804..146D 2015ApJ...804..146D, Cat. J/ApJ/804/146) Stromgren
15 = De Cat & Aerts (2002A&A...393..965D 2002A&A...393..965D, Cat. J/A+A/393/965) Geneva
16 = Silva & Napiwotzki (2011MNRAS.411.2596S 2011MNRAS.411.2596S, Cat. J/MNRAS/411/2596) Stromgren
17 = Zorec et al. (2009A&A...501..297Z 2009A&A...501..297Z, Cat. J/A+A/501/297) BCD method
18 = Silaj & Landstreet (2014A&A...566A.132S 2014A&A...566A.132S, Cat. J/A+A/566/A132)
Geneva/Stromgren
19 = Soubiran et al. (2016A&A...591A.118S 2016A&A...591A.118S, Cat. B/pastel) Spectral type
20 = Massey (2002ApJS..141...81M 2002ApJS..141...81M, Cat. II/236) UBVR photometry
21 = Niemczura et al. (2015MNRAS.450.2764N 2015MNRAS.450.2764N, Cat. J/MNRAS/450/2764)
Spectroscopy
22 = Huber et al. (2016ApJS..224....2H 2016ApJS..224....2H, Cat. J/ApJS/224/2) Spectroscopy
23 = Balona et al. (2011MNRAS.413.2403B 2011MNRAS.413.2403B) Spectroscopy
24 = Tkachenko et al. (2013MNRAS.431.3685T 2013MNRAS.431.3685T) Spectroscopy
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(End) Ana Fiallos [CDS] 23-Sep-2022