J/A+A/672/A93 AF Lep b spectrum (Mesa+, 2023)
AF Lep b: The lowest-mass planet detected by coupling astrometric and
direct imaging data.
Mesa D., Gratton R., Kervella P., Bonavita M., Desidera S., D'Orazi V.,
Marino S., Zurlo A., Rigliaco E.
<Astron. Astrophys. 672, A93 (2023)>
=2023A&A...672A..93M 2023A&A...672A..93M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Spectra, infrared
Keywords: instrumentation: spectrographs - methods: data analysis -
techniques: imaging spectroscopy - stars: planetary systems -
stars: individual: AF Lep
Abstract:
Using the direct imaging technique we searched for low mass companions
around the star AF Lep that presents a significant proper motion
anomaly (PMa) signal obtained from the comparison of Hipparcos and
Gaia eDR3 catalogs.
We observed AF Lep in two epochs with VLT/SPHERE using its subsystems
IFS and IRDIS in the near-infrared (NIR) covering wavelengths ranging
from the Y to the K spectral bands (between 0.95 and 2.3um). The data
were then reduced using the high-contrast imaging techniques angular
differential imaging (ADI) and spectral differential imaging (SDI) to
be able to retrieve the signal from low mass companions of the star.
A faint companion was retrieved at a separation of 0.335 arcsec from
the star and with a position angle of ∼70.5 degree in the first epoch
and with a similar position in the second epoch. This corresponds to a
projected separation of 9au. The extracted photometry allowed us to
estimate for the companion a mass between 2 and 5MJup. This mass is
in good agreement with what is expected for the dynamic mass of the
companion deduced using astrometric measures (5.2-5.5MJup). This is
the first companion with a mass well below the deuterium burning limit
discovered coupling direct imaging with PMa measures. Orbit fitting
done using the orvara tool allowed to further confirm the companion
mass and to define its main orbital parameters.
Description:
NIR spectrum of AF Lep b.
The SPHERE/SHINE observations of AF Lep, which were performed on
October 16, 2022, and December 20, 2022.
Objects:
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RA (2000) DE Designation(s)
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05 27 04.76 -11 54 03.4 AF Lep = HIP 25486
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
spectrum.dat 39 36 Spectrum of AF Lep b
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Byte-by-byte Description of file: spectrum.dat
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Bytes Format Units Label Explanations
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6- 13 F8.6 um lambda Wavelength
15- 26 E12.5 W/m2/um Flux Flux
29- 39 E11.5 W/m2/um e_Flux Error on flux
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Acknowledgements:
Dino Mesa, dino.mesa(at)inaf.it
(End) Patricia Vannier [CDS] 20-Feb-2023