Accurate Spitzer infrared radius measurement for the hot Neptune GJ 436b

M. Gillon; B. O. Demory; T. Barman; X. Bonfils; T. Mazeh; F. Pont; S. Udry; M. Mayor; D. Queloz

doi:10.1051/0004-6361:20078283

Accurate Spitzer infrared radius measurement for the hot Neptune GJ 436b

M. Gillon, B. O. Demory, T. Barman, X. Bonfils, T. Mazeh, F. Pont, S. Udry, M. Mayor, D. Queloz

Research output: Contribution to journal › Article › peer-review

111 Scopus citations

Abstract

We present Spitzer Space Telescope infrared photometry of a primary transit of the hot Neptune GJ 436b. The observations were obtained using the 8 μm band of the InfraRed Array Camera (IRAC). The high accuracy of the transit data and the weak limb-darkening in the 8 μm IRAC band allow us to derive (assuming M = 0.44 ±0.04 M_⊙ for the primary) a precise value for the planetary radius (4.19_-0.16^+0.21 R _⊕), the stellar radius (0.463_-0.017^+0.022 R_⊙) the orbital inclination (85.90° _-0.18°^+0.19°) and transit timing ((2454280.78186_-0.00008^+0.00015 HJD). Assuming current planet models, an internal structure similar to that of Neptune with a small H/He envelope is necessary to account for the measured radius of GJ 436b.

Original language	English (US)
Pages (from-to)	L51-L54
Journal	Astronomy and astrophysics
Volume	471
Issue number	3
DOIs	https://doi.org/10.1051/0004-6361:20078283
State	Published - Sep 2007
Externally published	Yes

Keywords

Eclipses
Infrared: general
Planetary systems
Stars: individual: GJ 436
Techniques: photometric

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

Access to Document

10.1051/0004-6361:20078283

Cite this

@article{02d903bf290145e3be6c7f8526b4c884,

title = "Accurate Spitzer infrared radius measurement for the hot Neptune GJ 436b",

abstract = "We present Spitzer Space Telescope infrared photometry of a primary transit of the hot Neptune GJ 436b. The observations were obtained using the 8 μm band of the InfraRed Array Camera (IRAC). The high accuracy of the transit data and the weak limb-darkening in the 8 μm IRAC band allow us to derive (assuming M = 0.44 ±0.04 M⊙ for the primary) a precise value for the planetary radius (4.19-0.16+0.21 R ⊕), the stellar radius (0.463-0.017+0.022 R⊙) the orbital inclination (85.90° -0.18°+0.19°) and transit timing ((2454280.78186-0.00008+0.00015 HJD). Assuming current planet models, an internal structure similar to that of Neptune with a small H/He envelope is necessary to account for the measured radius of GJ 436b.",

keywords = "Eclipses, Infrared: general, Planetary systems, Stars: individual: GJ 436, Techniques: photometric",

author = "M. Gillon and Demory, {B. O.} and T. Barman and X. Bonfils and T. Mazeh and F. Pont and S. Udry and M. Mayor and D. Queloz",

year = "2007",

month = sep,

doi = "10.1051/0004-6361:20078283",

language = "English (US)",

volume = "471",

pages = "L51--L54",

journal = "Astronomy and astrophysics",

issn = "0004-6361",

publisher = "EDP Sciences",

number = "3",

}

TY - JOUR

T1 - Accurate Spitzer infrared radius measurement for the hot Neptune GJ 436b

AU - Gillon, M.

AU - Demory, B. O.

AU - Barman, T.

AU - Bonfils, X.

AU - Mazeh, T.

AU - Pont, F.

AU - Udry, S.

AU - Mayor, M.

AU - Queloz, D.

PY - 2007/9

Y1 - 2007/9

N2 - We present Spitzer Space Telescope infrared photometry of a primary transit of the hot Neptune GJ 436b. The observations were obtained using the 8 μm band of the InfraRed Array Camera (IRAC). The high accuracy of the transit data and the weak limb-darkening in the 8 μm IRAC band allow us to derive (assuming M = 0.44 ±0.04 M⊙ for the primary) a precise value for the planetary radius (4.19-0.16+0.21 R ⊕), the stellar radius (0.463-0.017+0.022 R⊙) the orbital inclination (85.90° -0.18°+0.19°) and transit timing ((2454280.78186-0.00008+0.00015 HJD). Assuming current planet models, an internal structure similar to that of Neptune with a small H/He envelope is necessary to account for the measured radius of GJ 436b.

AB - We present Spitzer Space Telescope infrared photometry of a primary transit of the hot Neptune GJ 436b. The observations were obtained using the 8 μm band of the InfraRed Array Camera (IRAC). The high accuracy of the transit data and the weak limb-darkening in the 8 μm IRAC band allow us to derive (assuming M = 0.44 ±0.04 M⊙ for the primary) a precise value for the planetary radius (4.19-0.16+0.21 R ⊕), the stellar radius (0.463-0.017+0.022 R⊙) the orbital inclination (85.90° -0.18°+0.19°) and transit timing ((2454280.78186-0.00008+0.00015 HJD). Assuming current planet models, an internal structure similar to that of Neptune with a small H/He envelope is necessary to account for the measured radius of GJ 436b.

KW - Eclipses

KW - Infrared: general

KW - Planetary systems

KW - Stars: individual: GJ 436

KW - Techniques: photometric

UR - http://www.scopus.com/inward/record.url?scp=34548136093&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34548136093&partnerID=8YFLogxK

U2 - 10.1051/0004-6361:20078283

DO - 10.1051/0004-6361:20078283

M3 - Article

AN - SCOPUS:34548136093

SN - 0004-6361

VL - 471

SP - L51-L54

JO - Astronomy and astrophysics

JF - Astronomy and astrophysics

IS - 3

ER -

Accurate Spitzer infrared radius measurement for the hot Neptune GJ 436b

Abstract

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this