2017A&A...598A..62M


C.D.S. - SIMBAD4 rel 1.7 - 2020.07.04CEST13:51:49

2017A&A...598A..62M - Astronomy and Astrophysics, volume 598A, 62-62 (2017/2-1)

Dipole modes with depressed amplitudes in red giants are mixed modes.

MOSSER B., BELKACEM K., PINCON C., TAKATA M., VRARD M., BARBAN C., GOUPIL M.-J., KALLINGER T. and SAMADI R.

Abstract (from CDS):

Context. Seismic observations with the space-borne Kepler mission have shown that a number of evolved stars exhibit low-amplitude dipole modes, which is referred to as depressed modes. Recently, these low amplitudes have been attributed to the presence of a strong magnetic field in the stellar core of those stars. Subsequently, and based on this scenario, the prevalence of high magnetic fields in evolved stars has been inferred. It should be noted, however, that this conclusion remains indirect.
Aims. We intend to study the properties of mode depression in evolved stars, which is a necessary condition before reaching conclusions about the physical nature of the mechanism responsible for the reduction of the dipole mode amplitudes.
Methods. We perform a thorough characterization of the global seismic parameters of depressed dipole modes and show that these modes have a mixed character. The observation of stars showing dipole mixed modes that are depressed is especially useful for deriving model-independent conclusions on the dipole mode damping. We use a simple model to explain how mode visibilities are connected to the extra damping seen in depressed modes.
Results. Observations prove that depressed dipole modes in red giants are not pure pressure modes but mixed modes. This result, observed in more than 90% of the bright stars (mV≤11), invalidates the hypothesis that depressed dipole modes result from the suppression of the oscillation in the radiative core of the stars. Observations also show that, except for visibility, seismic properties of the stars with depressed modes are equivalent to those of normal stars. The measurement of the extra damping that is responsible for the reduction of mode amplitudes, without any prior on its physical nature, potentially provides an efficient tool for elucidating the mechanism responsible for the mode depression.
Conclusions. The mixed nature of the depressed modes in red giants and their unperturbed global seismic parameters carry strong constraints on the physical mechanism responsible for the damping of the oscillation in the core. This mechanism is able to damp the oscillation in the core but cannot fully suppress it. Moreover, it cannot modify the radiative cavity probed by the gravity component of the mixed modes. The recent mechanism involving high magnetic fields proposed for explaining depressed modes is not compliant with the observations and cannot be used to infer the strength and prevalence of high magnetic fields in red giants.

Abstract Copyright: © ESO, 2017

Journal keyword(s): stars: oscillations - stars: evolution - stars: magnetic field - stars: interiors

VizieR on-line data: <Available at CDS (J/A+A/598/A62): tablea1.dat>

Simbad objects: 74

goto Full paper

goto View the reference in ADS

Number of rows : 74

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 2MASS J18501107+4433185 RG* 18 50 11.0734038315 +44 33 18.505634619           K2III 7 0
2 KIC 5339823 HB* 18 52 28.6936824271 +40 33 21.924245778   12.92 11.36     G9IIIb 11 0
3 TYC 3131-790-1 Er* 18 52 58.2024526050 +43 51 57.461818486   11.91 10.81     ~ 6 0
4 KIC 11598312 Er* 18 57 17.6824778377 +49 40 38.833231683   11.28 10.09     ~ 13 0
5 KIC 8283646 RG* 18 58 33.4997965044 +44 12 00.060379652           ~ 12 0
6 KIC 2693261 Er* 19 03 49.8343707781 +37 55 46.302578462   11.60 10.36     K1.5III 12 0
7 KIC 6026983 RG* 19 04 00.5987932197 +41 19 52.380062691           ~ 8 0
8 KIC 10653383 RG* 19 04 57.2224444705 +47 55 32.311046847   12.05 11.15     ~ 14 0
9 2MASS J19055972+4309078 * 19 05 59.7276183630 +43 09 07.869300429           ~ 4 0
10 TYC 3554-327-1 Er* 19 10 00.7881135106 +51 21 04.651398377   10.83 9.72     ~ 5 0
11 KIC 7515137 RG* 19 10 23.1347047177 +43 11 56.231534436           ~ 13 0
12 KIC 3532734 RG* 19 11 15.6727924728 +38 38 26.563959952           ~ 11 0
13 2MASS J19134811+4115351 RG* 19 13 48.1179901903 +41 15 35.145116761           ~ 4 0
14 2MASS J19150161+4814442 RG* 19 15 01.6216024342 +48 14 44.184301965   12.06 11.17     G6III 7 0
15 2MASS J19162782+4614415 RG* 19 16 27.8203014863 +46 14 41.475099318           ~ 6 0
16 2MASS J19170783+4746579 RG* 19 17 07.8408257945 +47 46 57.961215519           ~ 4 0
17 2MASS J19181649+4023428 RG* 19 18 16.4945819317 +40 23 42.876849703           G6V 6 0
18 KIC 12058556 * 19 18 26.3879671854 +50 31 00.641577660           K2III 4 0
19 2MASS J19184514+4329193 RG* 19 18 45.1349988428 +43 29 19.330612056           K1IV 8 0
20 2MASS J19204680+4651505 * 19 20 46.8053167136 +46 51 50.440728511           ~ 3 0
21 KIC 6037858 RG* 19 21 15.4792932004 +41 21 56.205056968   11.32 10.04     ~ 11 0
22 2MASS J19220075+5148127 RG* 19 22 00.7625566099 +51 48 12.891144007   12.83 11.51     G8Iab: 6 0
23 TYC 3551-354-1 Er* 19 22 27.1035352824 +50 36 49.087590983   12.49 11.14     ~ 5 0
24 2MASS J19222889+4353191 RG* 19 22 28.8944065890 +43 53 19.177086583           ~ 5 0
25 2MASS J19223055+4006421 RG* 19 22 30.5527696757 +40 06 42.087804350           ~ 8 0
26 2MASS J19232571+3752335 RG* 19 23 25.7165293158 +37 52 33.637335300   12.85 11.70     ~ 12 0
27 2MASS J19241596+4450244 RG* 19 24 15.9652507774 +44 50 24.427377919           ~ 7 0
28 2MASS J19250672+4544536 RG* 19 25 06.7190058554 +45 44 53.696726547           ~ 7 0
29 KIC 3443483 RG* 19 25 35.1697242748 +38 32 01.792578893   13.13 11.81     K1IV 15 0
30 KIC 10469976 Er* 19 26 54.0399876756 +47 41 29.446478159   12.04 10.87     ~ 13 0
31 2MASS J19274517+4453557 RG* 19 27 45.1717532626 +44 53 55.799956866           ~ 7 0
32 2MASS J19280531+3806147 RG* 19 28 05.3266665417 +38 06 14.797170907   10.79 9.75     ~ 11 0
33 2MASS J19281060+4048488 RG* 19 28 10.6061087806 +40 48 48.832245696   13.23 11.41     ~ 7 0
34 KIC 9650046 RG* 19 28 43.9786587967 +46 21 26.711356570   12.85 11.93     G9III 13 0
35 KIC 9711269 RG* 19 28 59.6358978683 +46 24 42.572490634   11.28 10.13     K2IV 13 0
36 BD+44 3149 RG* 19 29 08.4408390104 +44 38 28.450809705   10.84 10.08 9.843   G9.5IV 29 0
37 2MASS J19293031+4426063 RG* 19 29 30.3205604071 +44 26 06.348682707   13.14 11.89     ~ 9 0
38 2MASS J19303199+3805240 RG* 19 30 31.9951201752 +38 05 24.068779938           ~ 4 0
39 BD+41 3381 RG* 19 32 15.6350742119 +42 02 58.307248605   10.35 9.49     F8 9 0
40 2MASS J19331251+4107291 RG* 19 33 12.5230926540 +41 07 29.062707903           ~ 4 0
41 2MASS J19335608+4133314 RG* 19 33 56.0877547387 +41 33 31.483217496           ~ 7 0
42 2MASS J19340565+4436190 * 19 34 05.6610171117 +44 36 19.074437646           ~ 3 0
43 KIC 8564559 RG* 19 34 31.1138872957 +44 41 58.993052733   12.87 11.86     K0III 14 0
44 2MASS J19360810+4126040 RG* 19 36 08.1050275258 +41 26 03.930996139           K0III 5 0
45 2MASS J19372862+3849032 RG* 19 37 28.6288842370 +38 49 03.273370373           ~ 7 0
46 2MASS J19401569+3844554 RG* 19 40 15.6919993257 +38 44 55.440712499           ~ 5 0
47 KIC 8827934 RG* 19 40 50.0113786322 +45 03 47.047083650   12.04 11.01     K2III 12 0
48 KIC 7693833 RG* 19 41 42.0434028485 +43 21 51.408119366   12.53 12.06     F8IV 12 0
49 KIC 11462972 Er* 19 42 16.4635158552 +49 19 08.052033721   11.18 10.18     ~ 13 0
50 2MASS J19422384+3953001 RG* 19 42 23.8463619679 +39 53 00.072144936           ~ 4 0
51 2MASS J19422653+4627428 RG* 19 42 26.5440090045 +46 27 42.834901809           G6V 6 0
52 TYC 3148-1485-1 Er* 19 43 35.2172684619 +44 42 53.192379043   10.31 9.26     K0III 7 0
53 2MASS J19433667+5035487 * 19 43 36.6740854795 +50 35 48.719488449           ~ 3 0
54 KIC 9291830 HB* 19 43 53.2836070174 +45 42 53.257501768   12.63 11.44     ~ 10 0
55 2MASS J19441280+4539558 RG* 19 44 12.8056814634 +45 39 55.876347138           ~ 7 0
56 KIC 11413158 RG* 19 46 04.5864910533 +49 16 00.327919648   11.78 10.70     ~ 14 0
57 2MASS J19463521+3914028 RG* 19 46 35.2191808117 +39 14 02.817009585   13.85 12.11     ~ 5 0
58 2MASS J19481571+4028595 RG* 19 48 15.7141951409 +40 28 59.605582908           G6V 8 0
59 KIC 11519450 RG* 19 48 38.1635447096 +49 26 39.781743977           ~ 10 0
60 2MASS J19495566+4732315 RG* 19 49 55.6526241549 +47 32 31.533052704           ~ 4 0
61 2MASS J19501975+3938489 RG* 19 50 19.7556429532 +39 38 48.892052162           ~ 6 0
62 KIC 10091729 RG* 19 50 34.8548653141 +47 03 39.363986757           K1IV 10 0
63 KIC 8771414 RG* 19 51 14.0735328136 +44 56 11.972355893           K1IV 10 0
64 2MASS J19513410+3952162 RG* 19 51 34.1009084189 +39 52 16.261572478   12.43 11.83     ~ 8 0
65 2MASS J19520159+4735260 RG* 19 52 01.5912846210 +47 35 26.071798756           ~ 7 0
66 2MASS J19525168+4655598 RG* 19 52 51.6798818626 +46 55 59.819173875           ~ 7 0
67 2MASS J19533041+4225446 RG* 19 53 30.4113238287 +42 25 44.596941869           ~ 8 0
68 2MASS J19554265+4131218 RG* 19 55 42.6605394850 +41 31 21.824562761   11.74 10.54     ~ 9 0
69 KIC 9176207 RG* 19 55 48.0879454587 +45 32 29.343151620           ~ 9 0
70 2MASS J19564214+4027227 RG* 19 56 42.1438327488 +40 27 22.862018548           ~ 4 0
71 2MASS J19581574+4421131 RG* 19 58 15.7444988596 +44 21 13.107786347           ~ 6 0
72 KIC 9115334 RG* 19 59 04.7264949625 +45 28 35.465535448   12.85 11.90     ~ 6 0
73 2MASS J20000175+4434477 RG* 20 00 01.7472189091 +44 34 47.782067984           G5V: 10 0
74 KIC 8396782 RG* 20 04 44.2333830381 +44 19 54.255998816   12.78 12.08     G6V 11 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2017A&A...598A..62M and select 'bookmark this link' or equivalent in the popup menu


2020.07.04-13:51:49

© Université de Strasbourg/CNRS

    • Contact