| | |
| | |
Stat |
Members: 3645 Articles: 2'506'133 Articles rated: 2609
27 April 2024 |
|
| | | |
|
Article overview
| |
|
First light of the VLT planet finder SPHERE. IV. Physical and chemical properties of the planets around HR8799 | M. Bonnefoy
; A. Zurlo
; J.L. Baudino
; P. Lucas
; D. Mesa
; A.-L. Maire
; A. Vigan
; R. Galicher
; D. Homeier
; F. Marocco
; R. Gratton
; G. Chauvin
; F. Allard
; S. Desidera
; M. Kasper
; C. Moutou
; A.-M. Lagrange
; A. Baruffolo
; J. Baudrand
; J.-L. Beuzit
; A. Boccaletti
; F. Cantalloube
; M. Carbillet
; J. Charton
; R.U. Claudi
; A. Costille
; K. Dohlen
; C. Dominik
; D. Fantinel
; P. Feautrier
; M. Feldt
; T. Fusco
; P. Gigan
; J. H. Girard
; L. Gluck
; C. Gry
; T. Henning
; M. Janson
; M. Langlois
; F. Madec
; Y. Magnard
; D. Maurel
; D. Mawet
; M. R. Meyer
; J. Milli
; O. Moeller-Nilsson
; D. Mouillet
; A. Pavlov
; D. Perret
; P. Pujet
; S. P. Quanz
; S. Rochat
; G. Rousset
; A. Roux
; B. Salasnich
; G. Salter
; J.-F. Sauvage
; H.M. Schmid
; A. Sevin
; C. Soenke
; E. Stadler
; M. Turatto
; S. Udry
; F. Vakili
; Z. Wahhaj
; F. Wildi
; | Date: |
12 Nov 2015 | Abstract: | The system of four planets around HR8799 offers a unique opportunity to probe
the physics and chemistry at play in the atmospheres of self-luminous young
(~30 Myr) planets. We recently obtained new photometry of the four planets and
low-resolution (R~30) spectra of HR8799 d and e with the SPHERE instrument
(paper III). In this paper (paper IV), we compare the available spectra and
photometry of the planets to known objects and atmospheric models (BT-SETTL14,
Cloud-AE60, Exo-REM) to characterize the atmospheric properties of the planets.
We find that HR8799d and e properties are well reproduced by those of L6-L8
dusty dwarfs discovered in the field, among which some are candidate members of
young nearby associations. No known object reproduces well the properties of
planets b and c. Nevertheless, we find that the spectra and WISE photometry of
peculiar and/or young early-T dwarfs reddened by submicron grains made of
corundum, iron, enstatite, or forsterite successfully reproduce the SED of
these two planets. Our analysis confirms that only the Exo-REM models with
thick clouds fit (within 2{sigma}) the whole set of spectrophotometric
datapoints available for HR8799 d and e for Teff = 1200 K, log g in the range
3.0-4.5, and M/H=+0.5. The models still fail to reproduce the SED of HR8799c
and b. The determination of the metallicity, log g, and cloud thickness are
degenerate. We conclude that an enhanced content in dust and decreased CIA of
H2 is certainly responsible for the deviation of the properties of the planet
with respect to field dwarfs. The analysis suggests in addition that HR8799c
and b have later spectral types than the two other planets, and therefore could
both have lower masses. | Source: | arXiv, 1511.4082 | Services: | Forum | Review | PDF | Favorites |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
| News, job offers and information for researchers and scientists:
| |