J/MNRAS/452/4283 33 RR Lyrae observed in Pisces with K2-E2 (Molnar+, 2015)
An RR Lyrae family portrait: 33 stars observed in Pisces with K2-E2.
Molnar L., Szabo R., Moskalik P.A., Nemec J.M., Guggenberger E., Smolec R.,
Poleski R., Plachy E., Kolenberg K., Kollath Z.
<Mon. Not. R. Astron. Soc., 452, 4283-4296 (2015)>
=2015MNRAS.452.4283M 2015MNRAS.452.4283M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable
Keywords: stars: variables: RR Lyrae
Abstract:
A detailed analysis is presented of 33 RR Lyrae stars in Pisces
observed with the Kepler space telescope over the 8.9-d long K2
Two-Wheel Concept Engineering Test. The sample includes not only
fundamental-mode and first-overtone (RRab and RRc) stars but the first
two double-mode (RRd) stars that Kepler detected and the only
modulated first-overtone star ever observed from space so far. The
precision of the extracted K2 light curves made it possible to detect
low-amplitude additional modes in all subtypes. All RRd and
non-modulated RRc stars show the additional mode at PX/P1∼0.61
that was detected in previous space-based photometric measurements. A
periodicity longer than the fundamental mode was tentatively
identified in one RRab star that might belong to a gravity mode. We
determined the photometric [Fe/H] values for all fundamental-mode
stars and provide the preliminary results of our efforts to fit the
double-mode stars with non-linear hydrodynamic pulsation models. The
results from this short test run indicate that the K2 mission will be,
and has started to be, an ideal tool to expand our knowledge about RR
Lyrae stars. As a by-product of the target search and analysis, we
identified 165 bona fide double-mode RR Lyrae stars from the Catalina
Sky Survey observations throughout the sky, 130 of which are new
discoveries.
Description:
Kepler observed a stellar field around the vernal equinox point in
Pisces (centre coordinates: RA=359°, DE=-2°) between 2014
February 04 and 13. The primary goal of this K2 Two-Wheel Concept
Engineering Test (hereafter K2-E2) was to test the performance of the
telescope in fine guidance mode. As well, the observations of nearly
2000 targets were made available for the scientific community.
We identified 33 potential RR Lyrae stars in the K2-E2 sample and
extracted their photometric data with the pyke software, developed
for the Kepler mission by the Kepler Guest Observer Office (Still &
Barclay, 2012, Astrophysics Source Code Library record ascl:1208.004).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 92 6 Double-mode and first-overtone RR Lyrae stars
observed during the Two-Wheel Concept
Engineering Test run of the K2 mission
table5.dat 100 27 Fundamental-mode RR Lyrae stars observed during
the Two-Wheel Concept Engineering Test run of
the K2 mission
table1.dat 40 14337 K2-E2 light-curve (for the 33 stars)
table2.dat 76 530 Frequency content of the K2-E2 RR Lyrae stars
(for the 33 stars)
tablea1.dat 80 165 *Sample table of the confirmed double-mode RR
Lyrae stars in the Catalina Surveys Periodic
Variable Stars Catalog
tablea2.dat 85 165 Sample table of the pulsation parameters of the
confirmed double-mode RR Lyrae stars
--------------------------------------------------------------------------------
Note on tablea1.dat: The list includes 165 stars, based on the examination of
the light curves of the stars originally labelled as 'RRd' or 'Blazhko' in
the catalogue, along with the two K2 stars.
--------------------------------------------------------------------------------
See also:
J/ApJ/765/154 : RR Lyrae stars in the Catalina Sky Survey (Drake+, 2013)
J/ApJS/213/9 : Catalina Surveys periodic variable stars (Drake+, 2014)
J/MNRAS/441/1230 : RRLyr stars in the Catalins Sky Survey (CS2) (Abbas+, 2014)
J/MNRAS/446/2251 : Southern Catalina Survey type-ab RR Lyrae (Torrealba+, 2015)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- EPIC EPIC star number
9 A1 --- n_EPIC Note on EPIC (1)
11- 19 F9.5 deg RAdeg Right ascension (J2000)
21- 29 F9.6 deg DEdeg Declination (J2000)
31- 36 F6.3 mag kepmag Kepler magnitude
37 A1 --- n_kepmag [*] Note on kepmag (2)
39- 46 F8.6 d P1 Period of the first overtone
48- 67 A20 --- Name Name of the star
69- 77 F9.6 d P0 ? Period of fundamental mode
78 A1 --- n_P0 [a] a: Modulation period
80- 92 I13 --- CSSID ? CSS ID number
--------------------------------------------------------------------------------
Note (1): This star has no EPIC ID but was observed within the pixel mask of
the engineering target EPIC 60042292.
Note (2): We provide estimated Kp magnitudes for these two stars (*).
The brightness of EPIC 60018238 is too high in the EPIC (Kp=9.83), compared to
the flux values.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Mod [abc] RRab modulation status (1)
3- 10 I8 --- EPIC EPIC star number
12- 20 F9.5 deg RAdeg Right ascension (J2000)
22- 30 F9.5 deg DEdeg Declination (J2000)
32- 37 F6.3 mag kepmag Kepler magnitude
39- 46 F8.6 d Per Period
48- 67 A20 --- Name Star name
69- 73 F5.2 [-] [Fe/H] Metallicity (average uncertainty is ±0.1)
75- 87 I13 --- CSSID ? CSS identification number
89- 92 F4.1 d Pm ? Blazhko period
94-100 A7 --- Notes Notes
--------------------------------------------------------------------------------
Note (1): Modulation status as follows:
a = Non-modulated RRab stars
b = Modulated RRab stars
c = Possibly modulated RRab stars
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- EPIC EPIC identification number
10- 21 F12.7 d BJD Barycentric Julian date (BDJ-2450000)
23- 31 F9.6 mag kepmag Kepler magnitude
33- 40 F8.6 mag e_kepmag rms uncertainty on Kepmag
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- EPIC EPIC star number
10- 18 F9.6 d-1 Freq Frequency
20- 28 F9.7 --- Amp Amplitude in kepmag unit
30- 37 F8.6 --- Phase Phase (in rad/2π unit)
39- 46 F8.6 d-1 e_Freq rms uncertainty on Freq
48- 56 F9.7 --- e_Amp rms uncertainty on Amp
57- 64 F8.6 --- e_Phase rms uncertainty on Pjase (in rad/2π unit)
66- 76 A11 --- ID Identification of the frequency (1)
--------------------------------------------------------------------------------
Note (1): Frequency identifications as follows:
f_0 = fundamental mode
f_1 = first overtone
f_2 = suspected second overtone
f_X = the common additional mode in RRc stars (also f_X' in one instance)
f_g = suspected gravity mode
f_corr = frequency of the attitude correction manoeuvres
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [CSS_]
5- 20 A16 --- CSS CSS name (JHHMMSS.s+DDMMSS)
22- 31 F10.6 deg RAdeg Right ascension (J2000)
33- 41 F9.5 deg DEdeg Declination (J2000)
43- 47 F5.2 mag mag Brightness
49- 61 I13 --- CSSID CSS identification number
63- 80 A18 --- OName Other ID
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [CSS_]
5- 20 A16 --- CSS CSS name (JHHMMSS.s+DDMMSS)
22- 31 F10.8 d P0 Period of fundamental mode
33- 42 F10.8 d e_P0 rms uncertainty on PerFM
44- 47 F4.2 mag Amp0 Amplitude of fundamental mode
49- 58 F10.8 d P1 Period of first overtone
60- 69 F10.8 d e_P1 rms uncertainty on PerO1
71- 74 F4.2 mag Amp1 Amplitude of first overtone
76- 85 F10.8 --- P1/P0 Period ratio, P1/P0
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 15-Mar-2016