2008A&A...480..215H

Query : 2008A&A...480..215H

2008A&A...480..215H - Astronomy and Astrophysics, volume 480, 215-222 (2008/3-2)

Precise radial velocities of giant stars. IV. A correlation between surface gravity and radial velocity variation and a statistical investigation of companion properties.

HEKKER S., SNELLEN I.A.G., AERTS C., QUIRRENBACH A., REFFERT S. and MITCHELL D.S.

Abstract (from CDS):

Since 1999, we have been conducting a radial velocity survey of 179 K giants using the Coude Auxiliary Telescope at UCO/Lick observatory. At present ∼20-100 measurements have been collected per star with a precision of 5 to 8m/s. Of the stars monitored, 145 (80%) show radial velocity (RV) variations at a level >20m/s, of which 43 exhibit significant periodicities. Our aim is to investigate possible mechanism(s) that cause these observed RV variations. We intend to test whether these variations are intrinsic in nature, or possibly induced by companions, or both. In addition, we aim to characterise the parameters of these companions. A relation between logg and the amplitude of the RV variations is investigated for all stars in the sample. Furthermore, the hypothesis that all periodic RV variations are caused by companions is investigated by comparing their inferred orbital statistics with the statistics of companions around main sequence F, G, and K dwarfs. A strong relation is found between the amplitude of the RV variations and logg in K giant stars, as suggested earlier by Hatzes & Cochran (1998, ASP Conf. Ser., 154, 311). However, most of the stars exhibiting periodic variations are located above this relation. These RV variations can be split in a periodic component which is not correlated with logg and a random residual part which does correlate with logg. Compared to main-sequence dwarf stars, K giants frequently exhibit periodic RV variations. Interpreting these RV variations as being caused by companions, the orbital parameters are different from the companions orbiting dwarfs. Intrinsic mechanisms play an important role in producing RV variations in K giants stars, as suggested by their dependence on logg. However, it appears that periodic RV variations are additional to these intrinsic variations, consistent with them being caused by companions. If indeed the majority of the periodic RV variations in K giants is interpreted as due to substellar companions, then massive planets are significantly more common around K giants than around F, G, K main-sequence stars.

Abstract Copyright: ∼

Journal keyword(s): stars: variables: general - techniques: radial velocities - line: profiles

Simbad objects: 55

goto Full paper

goto View the references in ADS

Number of rows : 55
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024 		#notes
1 * bet Cet PM* 00 43 35.37090 -17 59 11.7827 3.90 3.02 2.01 1.29 0.78 G9.5IIICH-1 525 1
2 * ups Per PM* 01 37 59.5580239328 +48 37 41.563066970 6.29 4.85 3.57 2.61 1.96 K3-IIICN0.5 232 0
3 * nu. Psc * 01 41 25.8941428289 +05 29 15.401884416 7.36 5.81 4.44 3.38 2.67 K3III 237 0
4 * eta02 Hyi PM* 01 54 56.1314447592 -67 38 50.291415024   5.623 4.685     G8IIIb 111 1
5 HD 13189 * 02 09 40.1723129208 +32 18 59.160568824   9.04 7.55     K1II-III 82 1
6 HD 17092 * 02 46 22.1182598088 +49 39 11.095466760   9.00 7.73     K2III 46 1
7 * 24 Per * 02 59 03.6768425424 +35 10 59.271233124 7.460 6.170 4.930     K2III 122 0
8 * sig Per V* 03 30 34.4853660216 +47 59 42.778854240 7.25 5.71 4.36     K3-III 124 0
9 HD 25723 * 04 04 22.7156192304 -12 47 32.268481764   6.688 5.611     K1III 39 0
10 * alf Tau LP? 04 35 55.23907 +16 30 33.4885 4.32 2.40 0.86 -0.37 -1.31 K5+III 1255 2
11 * iot Aur V* 04 56 59.6200224533 +33 09 57.937579478 6.00 4.22 2.69 1.63 0.81 K3II-III 277 0
12 * pi.06 Ori V* 04 58 32.9022894600 +01 42 50.448732336   5.853 4.459     K2-IIb 132 0
13 * nu.02 CMa PM* 06 36 41.0376788353 -19 15 21.169452656 5.96 5.011 3.91 3.13 2.61 K1.5III-IVFe1 260 1
14 HD 47526 * 06 39 54.5261300496 +19 52 19.187893740   9.49 9.44     A 4 0
15 * omi01 CMa s*r 06 54 07.9522701192 -24 11 03.159501504 7.59 5.60 3.87 2.70 1.88 K2Iab 176 0
16 * tet CMa PM* 06 54 11.3988612864 -12 02 19.061163780 7.20 5.51 4.08 2.95 2.17 K3/4III 218 0
17 * tau Gem PM* 07 11 08.3703137689 +30 14 42.589571474 7.08 5.68 4.42 3.45 2.82 K2III 158 1
18 HD 59686 PM* 07 31 48.4045109592 +17 05 09.764723724   6.574 5.442     K2III 113 1
19 BD-13 2130 * 07 37 09.2332503816 -13 54 23.956897032   11.31 10.04     G5IV-V/K2III 67 1
20 * alf CMi SB* 07 39 18.11950 +05 13 29.9552 0.82 0.79 0.37 -0.05 -0.28 F5IV-V+DQZ 1864 0
21 * bet Gem PM* 07 45 18.94987 +28 01 34.3160 3.00 2.14 1.14 0.39 -0.11 K0IIIb 1101 2
22 HD 63752 * 07 50 10.5764471832 -09 11 00.390967872   7.051 5.598     K2III 30 0
23 * 3 Cnc * 08 00 47.3075512008 +17 18 31.321989432   6.904 5.588     K3III 46 0
24 * bet Cnc PM* 08 16 30.9209888482 +09 11 07.958245527 6.750 5.000 3.520 2.42 1.62 K4IIIBa0.5: 366 0
25 * pi.02 UMa PM* 08 40 12.8171670288 +64 19 40.570243212 6.94 5.78 4.61 3.72 3.09 K1+III 165 1
26 * alf Hya * 09 27 35.24270 -08 39 30.9583 5.14 3.42 1.97 0.93 0.16 K3IIIa 434 1
27 * 18 Leo * 09 46 23.3273119968 +11 48 36.155648304   7.142 5.644     K4III 50 0
28 * 46 LMi PM* 10 53 18.6891667765 +34 12 53.611679098 5.79 4.87 3.83 3.00 2.46 K0+III-IV 236 0
29 * 44 UMa PM* 10 53 34.4520785448 +54 35 06.458632728   6.451 5.111     K3III 112 0
30 * chi UMa PM* 11 46 03.0140687528 +47 46 45.855272276 6.06 4.90 3.72 2.84 2.24 K0.5IIIb: 217 0
31 HD 104985 HB* 12 05 15.1171894272 +76 54 20.642733144       5.2   G8.5IIIb 154 1
32 NGC 4349 127 * 12 24 35.4709473000 -61 49 11.861413644   12.85 10.82     ~ 49 1
33 HD 115478 * 13 17 15.6279440976 +13 40 32.706746400 8.130 6.630 5.330     K3III 71 0
34 * alf Boo RG* 14 15 39.67207 +19 10 56.6730 2.46 1.18 -0.05 -1.03 -1.68 K1.5IIIFe-0.5 2318 1
35 * alf Cen A SB* 14 39 36.49400 -60 50 02.3737 0.96 0.72 0.01     G2V 1280 1
36 * ksi02 Lib * 14 56 46.1150412384 -11 24 34.920108828   6.946 5.450     K4III 72 0
37 * 110 Vir PM* 15 02 54.0375635908 +02 05 28.695699730 6.31 5.44 4.40 3.59 3.05 K0+IIIbFe-0.5 126 0
38 HD 135534 * 15 16 23.0106600888 -22 23 57.891494904   6.877 5.506     K2III 37 0
39 * iot Dra V* 15 24 55.7738042889 +58 57 57.837111857 5.68 4.45 3.29 2.51 1.91 K2III 409 1
40 * chi Sco * 16 13 50.9062585128 -11 50 15.892301544   6.615 5.239     K3III 69 0
41 * eps Oph PM* 16 18 19.2902245358 -04 41 33.047349888 4.95 4.21 3.23 2.54 2.05 G9.5IIIbFe-0.5 235 0
42 HD 148513 PM* 16 28 33.9807973104 +00 39 54.001143144 8.65 6.85 5.39     K3V 162 0
43 * e Oph PM* 17 18 36.9902276784 +10 51 52.111241856   6.550 5.020     K4II-III 71 0
44 HD 157617 * 17 23 57.6158315040 +08 51 09.252688284   6.999 5.763     K1III 35 0
45 * sig Oph V* 17 26 30.8807335272 +04 08 25.293765444 7.39 5.82 4.31 3.22 2.46 K2II 175 0
46 * lam Her V* 17 30 44.3098209648 +26 06 38.324204244 7.53 5.85 4.41 3.37 2.62 K3.5III 131 0
47 * tet Her V* 17 56 15.1809747319 +37 15 01.932000161 6.70 5.23 3.88 2.98 2.38 K1IIaCN2 215 0
48 * nu. Oph PM* 17 59 01.5922136612 -09 46 25.080976810 5.20 4.33 3.34 2.64 2.16 G9IIIa 212 1
49 * alf Sct PM* 18 35 12.4271571798 -08 14 38.653839451 6.70 5.17 3.83 2.86 2.18 K3III 182 0
50 HD 209761 * 22 05 11.3344094040 +26 40 25.285361988   7.016 5.744     K3III 40 0
51 * zet Cep s*r 22 10 51.2777055617 +58 12 04.542602641 6.62 4.90 3.35 2.27 1.49 K1.5Ib 278 0
52 HD 210762 * 22 12 08.0937068712 +24 57 02.313215568   7.432 5.923     K0 30 0
53 HD 211073 ** 22 13 52.7275081368 +39 42 53.728839720 7.32 5.88 4.49 3.48 2.74 K2.5III 112 0
54 HD 217303 PM* 23 00 05.7892478064 -25 09 51.047833032   6.904 5.656     K0IICNIII 23 0
55 * psi01 Aqr PM* 23 15 53.4940495770 -09 05 15.844964053 6.37 5.36 4.25 3.46 2.90 K1-IIIFe-0.5 244 1

To bookmark this query, right click on this link: simbad:objects in 2008A&A...480..215H and select 'bookmark this link' or equivalent in the popup menu