2012MNRAS.423.3420B

Query : 2012MNRAS.423.3420B

2012MNRAS.423.3420B - Mon. Not. R. Astron. Soc., 423, 3420-3429 (2012/July-2)

Kepler observations of flaring in A–F type stars.

BALONA L.A.

Abstract (from CDS):

Optical flares on early F- and A-type stars have never been observed with certainty. Inspection of several thousands of these stars in the Kepler public archives resulted in the discovery of flares in 25 G-type and 27 F-type stars. Because A-type stars are thought not to be active, the detection of flares on 19 A-type stars from a sample of nearly 2000 A stars is particularly noteworthy. The flares have relative intensities in the range 1–100 parts per thousand and typical durations of a few minutes to several hours. The mean interval between flares varies between 1 and 120 days. We estimate the typical energy of flares to be around 1035 erg in the F-type stars and about 1036 erg in the A-type stars. Nearly all these stars vary at a low level with a period which is most likely the rotational period of the star. Comparison of the relative flare intensities with those in cool red stars observed by Kepler shows that flares in these stars, and certainly in the A-type stars, cannot easily be ascribed to cool flare-star companions. The huge energy released in the flares is difficult to understand. This is especially the case for A-type stars since these stars are thought to have very weak magnetic fields. The flare energy may possibly originate in magnetic reconnection of field lines between the primary star and a companion.

Abstract Copyright: 2012 The Author Monthly Notices of the Royal Astronomical Society2012 RAS

Journal keyword(s): stars: activity - stars: flare - starspots

Simbad objects: 89

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Number of rows : 89
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026 		#notes
1 HD 2726 PM* 00 30 26.0632693104 -48 12 53.355477672   6.005 5.664     F2V 71 0
2 BD+47 819 * 03 25 29.4742567080 +47 58 02.343054936   9.63 9.26     A8V 50 0
3 * 71 Tau dS* 04 26 20.7708204936 +15 37 05.884087620   4.758 4.480 5.96 4.15 F0V 235 0
4 V* IQ Aur a2* 05 19 00.0284573784 +33 44 54.220806888   5.201 5.371     A0p 293 0
5 HD 290862 Y*O 05 46 43.3856873232 +00 04 36.042148164 10.93 11.04 10.41 10.24   B3/5 71 1
6 * bet Pic PM* 05 47 17.0876901 -51 03 59.441135 4.13 4.03 3.86 3.74 3.58 A6V 2087 1
7 HD 47777 Y*O 06 40 42.2934096648 +09 39 21.310266708 6.95 7.79 7.93   7.721 B2IV 125 0
8 HD 261902 Y*O 06 40 58.5126133512 +09 33 31.721892912 9.88 10.20 10.23   10.174 B8 49 0
9 * alf Gem A SB* 07 34 35.862828 +31 53 17.79429     1.9     A1.5IV+ 394 0
10 * alf02 CVn a2* 12 56 01.6655889007 +38 19 06.155170512 2.44 2.76 2.88 2.98 3.05 A0VpSiEu 707 0
11 HD 161804 * 17 48 35.6838653760 -23 21 27.235770768   10.78 10.24     A2/5(V) 14 0
12 * alf Lyr dS* 18 36 56.33635 +38 47 01.2802 0.03 0.03 0.03 0.07 0.10 A0V 2787 1
13 GALEX J184242.4+440405 HS* 18 42 42.4919250048 +44 04 05.580458256           sdB 12 0
14 TYC 3531-2010-1 * 18 43 13.2184356984 +47 39 46.075820004   11.98 11.70     G0V 12 0
15 TYC 3126-3182-1 Er* 18 49 26.2202071368 +42 38 58.523003556   11.76 11.48     F7IV 14 0
16 TYC 3127-104-1 * 18 50 32.7345932544 +43 01 38.782400628   10.86 10.14     G9V 24 0
17 ZTF J185516.63+473732.9 RS* 18 55 16.6337894088 +47 37 32.960077500           ~ 20 0
18 TYC 3127-2105-1 SB* 18 57 15.8156246712 +41 34 34.264099308   11.58 10.90     F5IV 9 0
19 TYC 3127-1423-1 Er* 18 57 32.9555387280 +42 41 47.966422056   11.64 11.78     B9.5Vn 12 0
20 TYC 3119-1230-1 SB* 18 59 14.9062991544 +38 45 46.280731716   11.90 11.26     G0-G2 25 0
21 HD 177152 * 19 01 21.7811743752 +44 23 11.470012044   7.54 7.57     B9V 37 0
22 TYC 3128-361-1 * 19 02 36.1224324624 +42 48 31.723434252   12.62 11.89     ~ 28 0
23 2MASS J19030055+4538080 dS* 19 03 00.5620715208 +45 38 08.013439464           A8V 9 0
24 ZTF J190534.83+452646.6 BY* 19 05 34.8544582872 +45 26 46.977918036           ~ 15 0
25 ZTF J190550.48+470021.3 BY* 19 05 50.4812000376 +47 00 21.068763804       13.230   K7V 25 0
26 KOI-6277 ** 19 07 22.876032 +37 48 57.34116   12.11 11.63 11.460   F2V+F9V 33 0
27 TYC 3124-2133-1 Er* 19 07 24.9987817920 +40 03 40.024986480   11.43 11.10     ~ 4 0
28 2MASS J19082450+4207306 Er* 19 08 24.5134650528 +42 07 30.547162452           G2V 14 0
29 ASAS J190858+4741.1 Em* 19 08 58.0480072944 +47 41 08.690796996   11.54 10.72   9.887 K1III 28 0
30 TYC 3550-936-1 Er* 19 09 40.4398554336 +49 30 05.160015900   11.75 11.08 10.698   G5IV 35 0
31 TYC 3542-458-1 gD* 19 10 03.5684057040 +46 42 16.074235764   11.92 11.76     F3V 9 0
32 TYC 3125-2558-1 SB* 19 12 58.9991449656 +40 26 42.215990280   11.81 11.19     F5IV 10 0
33 2MASS J19135844+4650001 * 19 13 58.4387335200 +46 50 00.167276076           ~ 6 0
34 ZTF J191455.08+465502.9 BY* 19 14 55.0752828024 +46 55 02.620147188           ~ 15 0
35 GALEX J191612.1+474915 HS* 19 16 12.1066804632 +47 49 15.393417780           sdB+F/G 17 0
36 TYC 3133-65-1 Er* 19 17 31.5727213800 +44 11 10.238843472   11.78 11.46     F6IV 21 0
37 TYC 3542-346-1 * 19 17 57.5931907440 +46 49 04.316865312   11.55 10.99     ~ 13 0
38 TYC 3542-1226-1 * 19 18 17.1499360728 +46 12 46.696452084   12.68 13.00     G1.5IV-V 12 0
39 TYC 3547-2631-1 Er* 19 19 05.0176884456 +48 27 52.495550280   11.52 11.37     A5V 11 0
40 TYC 3125-99-1 * 19 19 53.4929972784 +41 09 12.166052076   10.11 9.86     A7V 11 0
41 TYC 3138-950-1 * 19 21 49.5315056760 +39 50 07.411275132   11.35 10.71     ~ 28 0
42 TYC 3138-1050-1 SB* 19 21 58.0619883120 +39 59 54.426173460   11.47 10.73     G8 27 0
43 KOI-7401 V* 19 22 35.1359717016 +48 35 49.378409052   11.53 11.28     F3V 9 0
44 TYC 3146-445-1 * 19 23 35.6829970152 +44 52 51.573169596   10.84 10.70     A3V 12 0
45 TYC 3146-1276-1 * 19 23 59.6971105704 +43 35 26.544113268   12.18 11.49     ~ 14 0
46 TYC 3543-2942-1 gD* 19 24 20.8693033608 +45 39 16.681162932   12.24 12.07     A4V 18 0
47 2MASS J19242342+4328480 * 19 24 23.4198235104 +43 28 47.988453144           ~ 21 0
48 HD 183257 Er* 19 26 28.3861115160 +48 52 15.006208548   8.17 8.15     A1Va+n 27 0
49 UCAC4 696-066894 HS* 19 26 51.3848988312 +49 08 48.331033512     15.430 15.542   sdB+F/G 15 0
50 TYC 3551-827-1 * 19 27 09.7205726160 +48 47 47.664874932   11.18 10.60     ~ 18 0
51 TYC 3551-1491-1 Er* 19 28 12.7912627584 +49 27 16.185460176   12.03 11.78     F6V 7 0
52 BD+49 3025 ** 19 30 15.810576 +49 32 08.73132   10.67 9.82 9.61   K1V 33 0
53 1RXS J193016.8+493156 X 19 30 16.8 +49 31 56           ~ 3 0
54 TYC 3556-926-1 * 19 31 57.3162427800 +46 40 39.095361696   10.43 9.76     G2IV 23 0
55 TYC 3139-417-1 SB* 19 34 34.2888674808 +39 38 44.891127168   11.79 11.59     Am 8 0
56 2MASS J19353212+3933392 * 19 35 32.1180489936 +39 33 39.295185480           A1 9 0
57 BD+39 3829 * 19 35 36.716 +40 06 57.06           ~ 12 0
58 2MASS J19365987+4620314 * 19 36 59.8791406608 +46 20 31.504057800           ~ 17 0
59 TYC 3143-1629-1 * 19 37 16.8429361152 +42 13 48.151643628   11.64 11.16     ~ 5 0
60 2MASS J19372430+4224142 * 19 37 24.3046621008 +42 24 14.140420056           ~ 5 0
61 TYC 3135-147-1 Er* 19 37 35.7399245688 +38 32 10.133905704   12.09 11.66     ~ 3 0
62 2MASS J19374759+4148220 Er* 19 37 47.6018730456 +41 48 22.142431224           A2III-IV 9 0
63 ZTF J193912.57+470108.5 RS* 19 39 12.5785854504 +47 01 08.509798164           B9.5Vn 17 0
64 2MASS J19392821+4631022 * 19 39 28.2155230272 +46 31 02.189626752           ~ 5 0
65 TYC 3556-3372-1 * 19 40 33.6855617424 +45 55 21.277225956   11.94 11.68     G0V 24 0
66 TYC 3144-1666-1 Er* 19 42 10.4164172400 +42 17 59.183314764   11.01 10.57     F5V 11 0
67 HD 225447 gD* 19 42 12.6333322008 +40 17 45.907870236   9.286 9.173     A3IV-V 31 0
68 UCAC4 673-077720 V* 19 42 39.6576554976 +44 33 00.196013772   13.02 12.51 12.46 11.58 ~ 2 0
69 HD 225493 SB* 19 42 54.5712602400 +40 21 18.154831068   9.61 9.40     A4V 14 0
70 TYC 3557-1009-1 * 19 45 14.0741517552 +46 47 41.586567504   11.35 10.96     F5/F6IV/V 9 0
71 TYC 3148-1695-1 * 19 45 16.0781806536 +44 31 45.325434288   12.17 11.19     ~ 8 0
72 HD 225660 * 19 45 17.9914318560 +39 03 00.216870696   11.71 11.39     A2Ve 14 0
73 HD 187254 SB* 19 47 11.4301422264 +44 50 53.621412720   8.94 8.71     kA5hA5mF2V 42 0
74 BD+47 2934 SB* 19 50 14.2728443568 +47 28 25.166654760   9.68 9.24     F5IV-V 59 0
75 TYC 3149-1793-1 * 19 50 17.9645967840 +43 45 03.529583424   12.42 12.73     A1V 10 0
76 2MASS J19504258+4106069 dS* 19 50 42.5869083120 +41 06 06.997637988           A7Ve 8 0
77 * alf Aql dS* 19 50 46.99855 +08 52 05.9563 1.07 0.98 0.76 0.62 0.49 A7Vn 919 1
78 TYC 3145-177-1 Er* 19 51 46.4409052032 +43 07 24.524852412   12.82 11.73     G0IV 11 0
79 TYC 3141-1203-1 * 19 51 54.6845686874 +39 51 33.583404475   11.79 11.58     A2Ve 9 0
80 TYC 3145-420-1 * 19 52 05.5555438320 +41 59 45.342133836   11.52 11.06     ~ 15 0
81 UCAC4 652-079468 EB* 19 52 31.1799084072 +40 23 59.478954072   13.443 13.064 13.153   A1V 14 0
82 HD 188283 SB* 19 52 45.771192 +40 44 51.99000       9.027   B9IV 19 0
83 2MASS J19530794+4741490 * 19 53 07.9446323352 +47 41 48.858954108           A9V 10 0
84 TYC 3558-2497-1 gD* 19 53 09.3514518384 +45 05 53.718469404   11.67 11.09     F3V 14 0
85 TYC 3141-3352-1 * 19 54 14.3575241328 +40 41 45.047579064   11.88 11.25     F6IV 15 0
86 ASAS J195503+4055.3 Pu* 19 55 03.0032676720 +40 55 19.492221684     12.007   10.984 G2V 15 0
87 UCAC4 660-081619 Er* 19 56 23.3045079792 +41 51 14.919936012   12.554 11.985 11.847   ~ 12 0
88 TYC 3559-1528-1 SB* 20 04 28.2093365136 +45 11 51.226777608   11.66 11.27     kA7hA8mF4 15 0
89 HD 218396 El* 23 07 28.7157209544 +21 08 03.310767492   6.21 5.953     F0+VkA5mA5 1285 0

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