Sirius_Alpha Admin
Number of posts : 4320 Location : Earth Registration date : 2008-04-06
| Subject: Three Jovians around giant stars from CORALIE 5th January 2022, 9:47 pm | |
| CORALIE radial-velocity search for companions around evolved stars (CASCADES). I. Sample definition and first results: Three new planets orbiting giant stars https://arxiv.org/abs/2201.01528 - Quote :
- Context. Following the first discovery of a planet orbiting a giant star in 2002, we started the CORALIE radial-velocity search for companions around evolved stars (CASCADES). We present the observations of three stars conducted at the 1.2 m Leonard Euler Swiss telescope at La Silla Observatory, Chile, using the CORALIE spectrograph. Aims. We aim to detect planetary companions to intermediate-mass G- and K- type evolved stars and perform a statistical analysis of this population. We searched for new planetary systems around the stars HD22532 (TIC 200851704), HD64121 (TIC 264770836), and HD69123 (TIC 146264536). Methods. We have followed a volume-limited sample of 641 red giants since 2006 to obtain high-precision radial-velocity measurements. We used the Data & Analysis Center for Exoplanets (DACE) platform to perform a radial-velocity analysis to search for periodic signals in the line profile and activity indices, to distinguish between planetary-induced radial-velocity variations and stellar photospheric jitter, and to search for significant signals in the radial-velocity time series to fit a corresponding Keplerian model. Results. In this paper, we present the survey in detail, and we report on the discovery of the first three planets of the sample around the giant stars HD22532, HD64121, and HD69123.
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Edasich dK star
Number of posts : 2289 Location : Tau Ceti g - Mid Latitudes Registration date : 2008-06-02
| Subject: Re: Three Jovians around giant stars from CORALIE 6th January 2022, 1:32 pm | |
| Long time no hear of CORALIE news and results, such a nice update! I remember of two further substellar companion candidates around K to M giants from CORAVEL survey, it was back from 90s, namely 13 Bootis and Sigma Virginis, along with very controversial HD 3346, dou you remember this one? Sigma Virginis is also mentioned in a more recent paper I cannot retrieve at the moment wherein the orbiting companion hypothesis seemingly holds in respect with other sources of RV variability. Edit: Found it: Famaey et al. (2009). Actually they talk about possible pseudo-orbital variation for Sigma Virginis, so that the companion hypothesis is not entirely discarded. - Quote :
- The properties of the short-period variations would imply a rather low mass for the companion: assuming a mass of 1.3 M⊙ for the giant, the minimum mass for the companion is 0.054 M⊙, corresponding to a brown dwarf. It is not entirely clear whether the short-period variations are indeed due to an orbital motion, for several reasons.
However a binary stellar (likely WD) companion in wide (P = 29000 d) and highly eccentric orbit (e = 0.87) seems to be there. The inner putative BD companion is to be confirmed.
Last edited by Edasich on 10th January 2022, 3:50 pm; edited 5 times in total (Reason for editing : Updated bibliography) | |
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