J/A+A/699/A38 4 giant stars with planets radial velocities (Fontanet+, 2025)
CORALIE radial-velocity search for companions around evolved stars (CASCADES).
IV. New planetary systems around HD 87816, HD 94890, and HD 102888 and an
update on HD 121056.
Fontanet E., Udry S., Segransan D., Figueira P., Acevedo Barroso J.A.,
Akinsanmi B., Attia M., Battley M., Bhatnagar S., Bugatti M., Carteret Y.,
Chakraborty H., Deline A., Farret Jentink C., Frensch Y.G.C., Houelle M.,
Lavie B., Lovis C., Mayor M., Nigioni A., Ottoni G., Pepe F.,
Petit dit de la Roche D.J.M., Shinde M., Santos N.C., Tavella S., Unger N.,
Viviani G.
<Astron. Astrophys. 699, A38 (2025)>
=2025A&A...699A..38F 2025A&A...699A..38F (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Stars, giant ; Exoplanets ;
Radial velocities
Keywords: planets and satellites: detection -
stars: individual: HD 87816 - stars: individual: HD 94890 -
stars: individual: HD 102888 - stars: individual: HD 121056
Abstract:
With around 200 detections of exoplanets around giant stars to date,
our knowledge of the population of exoplanets orbiting evolved hosts
more massive than the Sun remains limited. The CORALIE radial-velocity
search for companions around evolved stars (CASCADES) was launched in
2006 with the aim of improving our understanding of the demographics
of exoplanets around intermediate-mass stars, by studying them once
they have evolved off the main sequence.
We intend to refine the current sample of known exoplanets orbiting
intermediate-mass (1.5-5M☉) giant stars of spectral types G and
early K. We searched for exoplanets orbiting the four stars HD 87816,
HD 94890, HD 102888, and HD 121056.
We used data obtained with the CORALIE spectrograph, mounted on the
Leonhard Euler Swiss telescope located at La Silla Observatory in
Chile. We gathered high-precision radial-velocity measurements over
more than ten years for each of the aforementioned targets. We started
by performing a search for periodic signals in the radial-velocity
time series of the four targets by using periodograms. Following this,
we fit for a Keplerian model using the significant peak with the
highest power of the periodogram as the starting guess for the period.
We then subtracted this model and repeated the procedure iteratively
on the residuals until no significant peaks were found. Finally, to
explore the posterior distribution of our models, the final solution
was determined using a Markov chain Monte Carlo approach.
We report the discovery of five new massive planets around HD 87816,
HD 94890, and HD 102888 as well as the presence of a distant,
potentially substellar, companion around HD 102888. We confirm the
presence of a previously announced exoplanet orbiting the HD 121056
multi-object system with a period of 89 days and propose an update to
the period of the outer companion.
Description:
CORALIE radial-velocity time series of the four targets studied in the
paper. For HD 121056, data from previous publication was also used in
the analysis.
Objects:
-----------------------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------------------
10 06 07.21 -52 11 16.5 HD 87816 = TIC 138998040
10 56 43.05 -37 08 15.9 HD 94890 = TIC 158543228
11 50 37.18 -27 16 40.5 HD 102888 = TIC 397394991
13 53 52.06 -35 18 51.6 HD 121056 = TIC 111947706
-----------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
hd87816.dat 42 91 RV time series of HD 87816
hd94890.dat 42 76 RV time series of HD 94890
hd102888.dat 42 36 RV time series of HD 102888
hd121056.dat 42 34 *RV time series of HD 121056
--------------------------------------------------------------------------------
Note on hd121056.dat: CHIRON and FEROS RV data was used for the analysis.
The data was originally published in Jones et al., 2015A&A...580A..14J 2015A&A...580A..14J,
Cat. J/A+A/580/A14 (HIP 67851).
--------------------------------------------------------------------------------
See also:
J/A+A/580/A14 : Radial Velocities of 3 giant stars with planets (Jones+, 2015)
J/A+A/657/A87 : CASCADES I. Sample definition and first results (Ottoni+, 2022)
Byte-by-byte Description of file: hd*.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 12 F11.5 d JD Reduced Julian date (JD-2450000)
15- 22 F8.2 m/s RV Radial velocity
27- 31 F5.2 m/s e_RV Radial velocity uncertainty
34- 42 A9 --- Inst Instrument name
--------------------------------------------------------------------------------
Acknowledgements:
Emile Fontanet, emile.fontanet(at)unige.ch
References:
Ottoni et al., Paper I 2022A&A...657A..87O 2022A&A...657A..87O, Cat. J/A+A/657/A87
Buldgen et al., Paper II 2022A&A...657A..88B 2022A&A...657A..88B
Pezzotti et al., Paper III 2022A&A...657A..89P 2022A&A...657A..89P
(End) Patricia Vannier [CDS] 20-May-2025