J/AJ/149/68 A-F type variable stars from Kepler (Bradley+, 2015)
Results of a search for γ Dor and δ Sct stars with the Kepler
spacecraft.
Bradley P.A., Guzik J.A., Miles L.F., Uytterhoeven K., Jackiewicz J.,
Kinemuchi K.
<Astron. J., 149, 68 (2015)>
=2015AJ....149...68B 2015AJ....149...68B
ADC_Keywords: Stars, variable ; Effective temperatures ; Stars, F-type ;
Stars, A-type
Keywords: space vehicles: instruments - stars: rotation -
stars: variables: delta Scuti - stars: variables: general
Abstract:
The light curves of 2768 stars with effective temperatures and surface
gravities placing them near the gamma Doradus (γ Dor)/delta
Scuti (δ Sct) instability region were observed as part of the
Kepler Guest Observer program from Cycles 1 through 5. The light
curves were analyzed in a uniform manner to search for γ Dor,
δ Sct, and hybrid star pulsations. The γ Dor, δ Sct,
and hybrid star pulsations extend asteroseismology to stars slightly
more massive (1.4-2.5M☉) than our Sun. We find 207 γ Dor,
84 δ Sct, and 32 hybrid candidate stars. Many of these stars are
cooler than the red edge of the γ Dor instability strip as
determined from ground-based observations made before Kepler. A few of
our γ Dor candidate stars lie on the hot side of the
ground-based γ Dor instability strip. The hybrid candidate stars
cover the entire region between 6200K and the blue edge of the
ground-based δ Sct instability strip. None of our candidate
stars are hotter than the hot edge of the ground-based δ Sct
instability strip. Our discoveries, coupled with the work of others,
show that Kepler has discovered over 2000 γ Dor, δ Sct,
and hybrid star candidates in the 116 square degree Kepler field of
view. We found relatively few variable stars fainter than magnitude
15, which may be because they are far enough away to lie between
spiral arms in our Galaxy, where there would be fewer stars.
Description:
The Kepler spacecraft (launched on 2009 March 6) monitors the
brightness variations of about 150000 stars in a 105 square degree
field between Cygnus and Lyra. The observations were obtained with a
single filter whose effective wavelength is close to that of the
Johnson R filter. The magnitudes from this bandpass are referred to as
Kepler magnitudes (Kp) in the Kepler Input Catalog (KIC, cat. V/133).
In our study, we select stars whose KIC parameters imply a location in
or near the δ Sct and γ Dor instability strips, that is,
late A to mid-F spectral types. We observed 2768 stars with Kepler as
part of the Guest Observer (GO) program.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 8 1237 Nonvariable (amplitude <30ppm) stars found in
our survey
table3.dat 69 207 γ Dor star candidates found in our survey
table4.dat 69 84 δ Sct star candidates found in our survey
table5.dat 53 32 Hybrid star candidates found in our survey
table6.dat 50 76 Binary stars found in our survey
table7.dat 32 1133 Rotating stars found in our survey
--------------------------------------------------------------------------------
See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
J/A+A/556/A52 : γ Dor stars from Kepler (Tkachenko+, 2013)
J/AJ/142/112 : KIC photometric calibration (Brown+, 2011)
J/A+A/534/A125 : Variability of Kepler A and F stars (Uytterhoeven+ 2011)
J/MNRAS/412/1210 : Kepler asteroseismic targets (Molenda-Zakowicz+, 2011)
http://archive.stsci.edu/kepler : MAST Kepler
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC Kepler Input Catalog identifier
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table[34].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC Kepler Input Catalog identifier
10- 13 F4.1 mag Kpmag Kepler magnitude
15- 18 I4 K Teff ? Effective temperature (1)
20- 21 A2 --- f_Teff NA for not analysed
23- 25 F3.1 [cm/s2] logg ? Log surface gravity (1)
27- 28 A2 --- f_logg NA for not analysed
30- 37 A8 --- Class Morphological classification (2)
39- 43 F5.2 d-1 Freq0 [0.2/24] Lower end of frequency range
45- 49 F5.2 d-1 Freq1 [0.4/25] Upper end of frequency range
51- 60 F10.3 ppm Amp [32/611990] Amplitude of highest mode in the
Fourier transform (FT)
62- 69 F8.5 d-1 Freq [0.2/4] Frequency of highest amplitude mode
--------------------------------------------------------------------------------
Note (1): These values are rounded from the Kepler Input Catalog (cat. V/133).
Note (2): Our classification of variable star types is defined as follows:
ASYM = Asymmetric;
MULT = Multiple periods;
SYM = Symmetric;
ROT = Rotating star with dominant low frequency;
HADS = High amplitude δ Sct star;
Other = Stars that do not fall in either of the other categories.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC Kepler Input Catalog identifier
10- 13 F4.1 mag Kpmag Kepler magnitude
15- 18 I4 K Teff Effective temperature
20- 22 F3.1 [cm/s2] logg Log surface gravity
24- 28 A5 --- Class Morphological classification (1)
30- 33 I4 ppm gAmp Amplitude of the highest mode in the γ Dor
region (<5day-1) of the Fourier transform (FT)
35- 40 F6.4 d-1 gFreq Frequency of the highest amplitude mode in the
γ Dor region (<5day-1) of the FT
42- 45 I4 ppm dAmp Amplitude of the highest mode in the
δ Sct region (>5day-1) of the FT
47- 53 F7.4 d-1 dFreq Frequency of the highest amplitude mode in the
δ Sct region (>5day-1) of the FT
--------------------------------------------------------------------------------
Note (1): Our classification of variable star types is defined as follows:
gDor = γ Dor-dominated Fourier transform;
dSct = δ Sct-dominated Fourier transform;
Equal = γ Dor and δ Sct amplitudes are within a factor of
seven of each other and are placed in the "equal" bin.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC Kepler Input Catalog identifier
10- 12 A3 --- f_KIC Indicates a binary system discovered in this
study (1)
14- 17 F4.1 mag Kpmag Kepler magnitude
19- 22 I4 K Teff ? Effective temperature
24- 25 A2 --- f_Teff NA for not analysed
27- 29 F3.1 [cm/s2] logg ? Log surface gravity
31- 32 A2 --- f_logg NA for not analysed
34- 42 A9 --- Class Morphological classification (2)
43 A1 --- u_Class [?] Uncertainty flag on Class
45- 50 F6.3 d Per [0.2/63] Orbital period
--------------------------------------------------------------------------------
Note (1): Binary star not in the Kepler binary star database.
Note (2): Our classification of variable star types is defined as follows:
EA = Detached binary that show obvious eclipses, but no ellipsoidal
effects;
EB = Contact (or ellipsoidal) eclipsing binary;
Heartbeat = Binary star in eccentric orbit where the star become tidally
distorted near periastron passage, causing a sudden rise in the
light curve (see Thompson et al., 2012ApJ...753...86T 2012ApJ...753...86T);
Transit = Star that have irregular light curve (due to starspots or rotation)
punctuated by narrow eclipses.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC Kepler Input Catalog identifier
10- 13 F4.1 mag Kpmag Kepler magnitude
15- 18 I4 K Teff Effective temperature
20- 22 F3.1 [cm/s2] logg Log surface gravity
24- 32 A9 --- Class Morphological classification (1)
--------------------------------------------------------------------------------
Note (1): Our classification of variable star types is defined as follows:
ROT = Rotating star that shows low frequency (typically <1c/day) power in
the Fourier transform (FT) and a modulated light curve, but no clear
peaks in the FT like the SPOTM and SPOTV stars. Their variations may be
due to rotation, but if so, the spots are not stable for more than a
few rotation periods;
SPOTM = Rotating star that shows a clear beat pattern and two dominant peaks in
the FT;
SPOTV = Rotating star that has a a single dominant peak in the FT and shows a
repeating light curve that can be explained by a single spot rotating
in and out of view;
VAR = Star that shows low frequency variability, but with no clear period in
the light curve or the FT. We cannot ascribe an obvious physical
mechanism to the variations.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 04-Mar-2015