2010A&A...511A..54S


Query : 2010A&A...511A..54S

2010A&A...511A..54S - Astronomy and Astrophysics, volume 511, A54-54 (2010/2-2)

Do stellar magnetic cycles influence the measurement of precise radial velocities?

SANTOS N.C., GOMES DA SILVA J., LOVIS C. and MELO C.

Abstract (from CDS):

The ever increasing level of precision achieved by present and future radial-velocity instruments is opening the way to discovering very low-mass, long-period planets (e.g. solar-system analogs). These systems will be detectable as low-amplitude signals in radial-velocity (RV). However, an important obstacle to their detection may be the existence of stellar magnetic cycles on similar timescales. Here we present the results of a long-term program to simultaneously measure radial-velocities and stellar-activity indicators (CaII, Hα, HeI) for a sample of stars with known activity cycles. Our results suggest that all these stellar activity indexes can be used to trace the stellar magnetic cycle in solar-type stars. Likewise, we find clear indications that different parameters of the HARPS cross-correlation function (BIS, FWHM, and contrast) are also sensitive to activity level variations. Finally, we show that, although in a few cases slight correlations or anti-correlations between radial-velocity and the activity level of the star exist, their origin is still not clear. We can, however, conclude that for our targets (early-K dwarfs) we do not find evidence of any radial-velocity variations induced by variations of the stellar magnetic cycle with amplitudes significantly above ∼1m/s.

Abstract Copyright:

Journal keyword(s): planetary systems - stars: fundamental parameters - techniques: spectroscopic - techniques: radial velocities - stars: activity - starspots

VizieR on-line data: <Available at CDS (J/A+A/511/A54): table1.dat table5.dat table6.dat table7.dat table8.dat>

Simbad objects: 13

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Number of rows : 13
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 HD 4628 PM* 00 48 22.9759750919 +05 16 50.209484954 7.22 6.64 5.74 4.99 4.52 K2.5V 473 0
2 HD 16160B LM* 02 36 04.66 +06 53 14.8     16.77     M6V 28 1
3 HD 16160 PM* 02 36 04.9013368983 +06 53 12.383654295   6.81   5.2   K3V 515 1
4 * omi02 Eri Er* 04 15 16.3196189945 -07 39 10.330779018 5.69 5.25 4.43 3.74 3.29 K0V 778 0
5 HD 32147 PM* 05 00 48.9993452248 -05 45 13.224327192 8.27 7.27 6.21 5.36 4.87 K3+V 433 1
6 HD 32146 * 05 00 50.3706610368 -04 26 50.611198776   9.31 9.13 9.2   A5V 6 0
7 HD 152391 PM* 16 52 58.8025159848 -00 01 35.118396116   7.40 6.64     G8.5Vk: 353 0
8 HD 160346 SB* 17 39 16.9163262 +03 33 18.875718   7.496 6.525 5.9   K3-V 283 0
9 HD 166435 PM* 18 09 21.3816898440 +29 57 06.166145376   7.457 6.829     G1IV 179 0
10 HD 321467 * 18 13 50.1895621176 -34 38 58.324208316   11.61 11.23     F0 3 0
11 HD 189733 BY* 20 00 43.7129433648 +22 42 39.073143456 9.241 8.578 7.648 7.126 6.68 K2V 814 1
12 * sig Peg PM* 22 52 24.0744611045 +09 50 08.394417666   5.64   4.9   F6V 271 0
13 * 94 Aqr SB* 23 19 06.7191981624 -13 27 31.825994400   5.95 5.18     G8.5IV 203 0

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2022.09.26-10:28:36

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