J/ApJ/805/94 Periodicities in KIC 3527751 from 3yr Kepler data (Foster+, 2015)
The discovery of differential radial rotation in the pulsating subdwarf B star
KIC 3527751.
Foster H.M., Reed M.D., Telting J.H., Ostensen R.H., Baran A.S.
<Astrophys. J., 805, 94 (2015)>
=2015ApJ...805...94F 2015ApJ...805...94F
ADC_Keywords: Stars, subdwarf ; Stars, variable ; Stars, B-type
Keywords: stars: horizontal-branch; stars: individual: KIC 3527751;
stars: oscillations; stars: rotation; subdwarfs
Abstract:
We analyze 3yr of nearly continuous Kepler spacecraft short cadence
observations of the pulsating subdwarf B (sdB) star KIC 3527751. We
detect a total of 251 periodicities, most in the g-mode domain, but
some where p-modes occur, confirming that KIC3527751 is a hybrid
pulsator. We apply seismic tools to the periodicities to characterize
the properties of KIC3527751. Techniques to identify modes include
asymptotic period spacing relationships, frequency multiplets, and the
separation of multiplet splittings. These techniques allow for 189
(75%) of the 251 periods to be associated with pulsation modes.
Included in these are three sets of l=4 multiplets and possibly an l=9
multiplet. Period spacing sequences indicate l=1 and 2 overtone
spacings of 266.4±0.2 and 153.2±0.2s, respectively. We also
calculate reduced periods, from which we find evidence of trapped
pulsations. Such mode trappings can be used to constrain the
core/atmosphere transition layers. Interestingly, frequency multiplets
in the g-mode region, which sample deep into the star, indicate a
rotation period of 42.6±3.4days while p-mode multiplets, which
sample the outer envelope, indicate a rotation period of
15.3±0.7days. We interpret this as differential rotation in the
radial direction with the core rotating more slowly. This is the first
example of differential rotation for a sdB star.
Objects:
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RA (ICRS) DE Designation(s)
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19 03 37.02 +38 36 12.6 KIC 3527751 = SDSS J190337.02+383612.6
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 79 251 Asteroseismic quantities
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
J/A+A/572/A34 : Pulsating solar-like stars in Kepler (Garcia+, 2014)
J/A+A/569/A15 : KIC 10553698A asteroseismology (Ostensen+, 2014)
J/AJ/147/45 : Kepler mission. IV. Binaries eclipse times (Conroy+, 2014)
J/A+A/559/A35 : FBS 0117+396 pulsating sdB star photometry (Ostensen+, 2013)
J/MNRAS/422/2600 : KOI-74 radial velocities and fluxes (Bloemen+, 2012)
J/MNRAS/421/181 : EC 01541-1409 pulsations frequencies (Reed+, 2012)
J/MNRAS/409/1470 : Kepler compact pulsator candidates (Ostensen+, 2010)
J/MNRAS/408/L51 : 2M1938+4603 (KIC 9472174) eclipses (Ostensen+, 2010)
J/ApJ/718/L97 : Early asteroseismic results from Kepler (Van Grootel+, 2010)
J/A+A/513/A6 : NOT survey of subdwarf B stars (Ostensen+, 2010)
J/A+A/459/557 : Oscillation modes of PG 1325+101 (Silvotti+, 2006)
J/A+A/400/939 : Stellar parameters of 115 HQS sdB stars (Edelmann+, 2003)
http://archive.stsci.edu/kepler/ : MAST Kepler home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- ID Periodicity identifier (among f001-f251 and
t218-t246) (1)
6- 8 A3 --- f_ID [d*] variations or combined frequency (2)
10- 17 F8.3 uHz Freq [72/3704] Frequency
19- 23 F5.3 uHz e_Freq [0.004/0.2] Uncertainty in Freq
25- 33 F9.3 s Per [269.9/13884] Period
35- 39 F5.3 s e_Per [0.001/8.1] Uncertainty in Per
41- 44 F4.2 10-3 Amp [0.1/7.2] Amplitude in parts per thousand
46 I1 --- l [0/9]? Best estimate ℓ mode identification
48- 51 A4 --- n_l Note on ℓ mode (ambiguity)
53- 54 I2 --- m [-9/9]? Best estimate m mode identification
56- 57 I2 --- nl1 [6/40]? Best estimate nℓ=1 mode
identification (see section 3)
59- 60 I2 --- nl2 [4/68]? Best estimate nℓ=2 mode
identification (see section 3)
62- 66 F5.2 --- (dP/P)1 [-0.1/0.4]? Period spacing deviation for ℓ=1
68- 72 F5.2 --- (dP/P)2 [-0.5/0.7]? Period spacing deviation for ℓ=2
74- 79 F6.4 uHz delf [0.06/6]? Frequency splitting δf (3)
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Note (1): Periodicities listed with "t"s instead of "f"s are below the
5σ limit and therefore considered tentative.
Note (2): Flag as follows:
d = periodicity detected by Reed et al. (2010MNRAS.409.1496R 2010MNRAS.409.1496R);
* = frequency is listed in Table 2 as part of a combination frequency.
Note (3): Frequency splitting (from the subsequent frequency) of
multiplet members.
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Emmanuelle Perret [CDS] 10-Sep-2015