The GTC exoplanet transit spectroscopy survey V. A spectrally-resolved Rayleigh scattering slope in GJ 3470b

doi:10.1051/0004-6361/201630228

	The GTC exoplanet transit spectroscopy survey V. A spectrally-resolved Rayleigh scattering slope in GJ 3470b
	Chen, G.1,2,3; Guenther, E. W.1,4; Palle, E.1,2; Nortmann, L.1,2; Nowak, G.1,2; Kunz, S.4; Parviainen, H.1,2; Murgas, F.1,2
刊名	ASTRONOMY & ASTROPHYSICS
	2017-04-01
卷号	600 页码:12
关键词	planetary systems planets and satellites: individual: GJ 3470b planets and satellites: atmospheres techniques: spectroscopic
ISSN号	1432-0746
DOI	10.1051/0004-6361/201630228
通讯作者	Chen, G.(gchen@iac.es)
英文摘要	Aims. As a sub-Uranus-mass low-density planet, GJ 3470b has been found to show a flat featureless transmission spectrum in the infrared and a tentative Rayleigh scattering slope in the optical. We conducted an optical transmission spectroscopy project to assess the impacts of stellar activity and to determine whether or not GJ 3470b hosts a hydrogen-rich gas envelop. Methods. We observed three transits with the low-resolution Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy (OSIRIS) at the 10.4 m Gran Telescopio Canarias, and one transit with the high-resolution Ultraviolet and Visual Echelle Spectrograph (UVES) at the 8.2 m Very Large Telescope. Results. From the high-resolution data, we find that the difference of the Ca II H+K lines in-and out-of-transit is only 0 : 67 +/- 0 : 22%, and determine a magnetic filling factor of about 10-15%. From the low-resolution data, we present the first optical transmission spectrum in the 435-755 nm band, which shows a slope consistent with Rayleigh scattering. Conclusions. After exploring the potential impacts of stellar activity in our observations, we confirm that Rayleigh scattering in an extended hydrogen-helium atmosphere is currently the best explanation. Further high-precision observations that simultaneously cover optical and infrared bands are required to answer whether or not clouds and hazes exist at high-altitude.
WOS关键词	HUBBLE-SPACE-TELESCOPE ; FLAT TRANSMISSION SPECTRUM ; EXTRASOLAR PLANET ; LIGHT CURVES ; HD 189733B ; MODEL ATMOSPHERES ; THERMAL EMISSION ; STELLAR ACTIVITY ; WATER-VAPOR ; BLUE SKY
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	EDP SCIENCES S A
WOS记录号	WOS:000400754000133
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/23102]
专题	中国科学院紫金山天文台
通讯作者	Chen, G.
作者单位	1.Inst Astrofis Canarias, Via Lactea S-N, Tenerife 38205, Spain 2.Univ La Laguna, Dept Astrofis, San Cristobal la Laguna, Spain 3.Chinese Acad Sci, Purple Mt Observ, Key Lab Planetary Sci, Nanjing 210008, Jiangsu, Peoples R China 4.Thuringer Landessternwarte Tautenburg, Sternwarte 5, D-07778 Tautenburg, Germany
推荐引用方式 GB/T 7714	Chen, G.,Guenther, E. W.,Palle, E.,et al. The GTC exoplanet transit spectroscopy survey V. A spectrally-resolved Rayleigh scattering slope in GJ 3470b[J]. ASTRONOMY & ASTROPHYSICS,2017,600:12.
APA	Chen, G..,Guenther, E. W..,Palle, E..,Nortmann, L..,Nowak, G..,...&Murgas, F..(2017).The GTC exoplanet transit spectroscopy survey V. A spectrally-resolved Rayleigh scattering slope in GJ 3470b.ASTRONOMY & ASTROPHYSICS,600,12.
MLA	Chen, G.,et al."The GTC exoplanet transit spectroscopy survey V. A spectrally-resolved Rayleigh scattering slope in GJ 3470b".ASTRONOMY & ASTROPHYSICS 600(2017):12.