Metals in the exosphere of the highly irradiated planet WASP-12b

L. Fossati; C. A. Haswell; C. S. Froning; L. Hebb; S. Holmes; U. Kolb; Ch. Helling; A. Carter; P. Wheatley; A. C. Cameron; B. Loeillet; D. Pollacco; R. Street; H. C. Stempels; E. Simpson; S. Udry; Y. C. Joshi; R. G. West; I. Skillen; D. Wilson

doi:10.1088/2041-8205/714/2/L222

Metals in the exosphere of the highly irradiated planet WASP-12b

L. Fossati, C. A. Haswell, C. S. Froning, L. Hebb, S. Holmes, U. Kolb, Ch. Helling, A. Carter, P. Wheatley, A. C. Cameron, B. Loeillet, D. Pollacco, R. Street, H. C. Stempels, E. Simpson, S. Udry, Y. C. Joshi, R. G. West, I. Skillen, D. Wilson

School of Physics and Astronomy

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

Abstract

We present near-UV transmission spectroscopy of the highly irradiated transiting exoplanet WASP-12b, obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope. The spectra cover three distinct wavelength ranges: NUVA (2539-2580 angstrom), NUVB (2655-2696 angstrom), and NUVC (2770-2811 angstrom). Three independent methods all reveal enhanced transit depths attributable to absorption by resonance lines of metals in the exosphere of WASP-12b. Light curves of total counts in the NUVA and NUVC wavelength ranges show a detection at a 2.5 sigma level. We detect extra absorption in the Mg II lambda lambda 2800 resonance line cores at the 2.8 sigma level. The NUVA, NUVB, and NUVC light curves imply effective radii of 2.69 +/- 0.24 R-J, 2.18 +/- 0.18 R-J, and 2.66 +/- 0.22 R-J respectively, suggesting the planet is surrounded by an absorbing cloud which overfills the Roche lobe. We detect enhanced transit depths at the wavelengths of resonance lines of neutral sodium, tin, and manganese, and at singly ionized ytterbium, scandium, manganese, aluminum, vanadium, and magnesium. We also find the statistically expected number of anomalous transit depths at wavelengths not associated with any known resonance line. Our data are limited by photon noise, but taken as a whole the results are strong evidence for an extended absorbing exosphere surrounding the planet. The NUVA data exhibit an early ingress, contrary to model expectations; we speculate this could be due to the presence of a disk of previously stripped material.

Original language	English
Pages (from-to)	L222-L227
Number of pages	6
Journal	Astrophysical Journal Letters
Volume	714
Issue number	2
DOIs	https://doi.org/10.1088/2041-8205/714/2/L222
Publication status	Published - 10 May 2010

Keywords

stars: individual (WASP-12)
LINE-DATA-BASE
RESONANCE-ABSORPTION LINES
ENERGETIC NEUTRAL ATOMS
EXOPLANET HD-209458B
EXTRASOLAR PLANET
WAVELENGTHS LONGWARD
LYMAN LIMIT
HD 209458B
ATMOSPHERE
EVAPORATION

Access to Document

10.1088/2041-8205/714/2/L222

Astrophysics in St Andrews: Astrophysics in St Andrews / SUPA (Continuan of Rolling Grant - XPP089
Bonnell, I. A. (PI), Cameron, A. C. (CoI), Dominik, M. (CoI), Driver, S. P. (CoI), Greaves, J. S. (CoI), Horne, K. D. (CoI), Jardine, M. M. (CoI), Wood, K. (CoI) & Zhao, H. (CoI)
Science & Technology Facilities Council
1/04/09 → 31/03/12
Project: Standard
Wide Area Search for Planets: Project support for the Wide Area Search for Planets
Cameron, A. C. (PI)
Science & Technology Facilities Council
1/08/08 → 31/07/11
Project: Standard

Cite this

Fossati, L., Haswell, C. A., Froning, C. S., Hebb, L., Holmes, S., Kolb, U., Helling, C., Carter, A., Wheatley, P., Cameron, A. C., Loeillet, B., Pollacco, D., Street, R., Stempels, H. C., Simpson, E., Udry, S., Joshi, Y. C., West, R. G., Skillen, I., & Wilson, D. (2010). Metals in the exosphere of the highly irradiated planet WASP-12b. Astrophysical Journal Letters, 714(2), L222-L227. https://doi.org/10.1088/2041-8205/714/2/L222

@article{56802c5968314e32a070a0e829f9286f,

title = "Metals in the exosphere of the highly irradiated planet WASP-12b",

abstract = "We present near-UV transmission spectroscopy of the highly irradiated transiting exoplanet WASP-12b, obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope. The spectra cover three distinct wavelength ranges: NUVA (2539-2580 angstrom), NUVB (2655-2696 angstrom), and NUVC (2770-2811 angstrom). Three independent methods all reveal enhanced transit depths attributable to absorption by resonance lines of metals in the exosphere of WASP-12b. Light curves of total counts in the NUVA and NUVC wavelength ranges show a detection at a 2.5 sigma level. We detect extra absorption in the Mg II lambda lambda 2800 resonance line cores at the 2.8 sigma level. The NUVA, NUVB, and NUVC light curves imply effective radii of 2.69 +/- 0.24 R-J, 2.18 +/- 0.18 R-J, and 2.66 +/- 0.22 R-J respectively, suggesting the planet is surrounded by an absorbing cloud which overfills the Roche lobe. We detect enhanced transit depths at the wavelengths of resonance lines of neutral sodium, tin, and manganese, and at singly ionized ytterbium, scandium, manganese, aluminum, vanadium, and magnesium. We also find the statistically expected number of anomalous transit depths at wavelengths not associated with any known resonance line. Our data are limited by photon noise, but taken as a whole the results are strong evidence for an extended absorbing exosphere surrounding the planet. The NUVA data exhibit an early ingress, contrary to model expectations; we speculate this could be due to the presence of a disk of previously stripped material.",

keywords = "stars: individual (WASP-12), LINE-DATA-BASE, RESONANCE-ABSORPTION LINES, ENERGETIC NEUTRAL ATOMS, EXOPLANET HD-209458B, EXTRASOLAR PLANET, WAVELENGTHS LONGWARD, LYMAN LIMIT, HD 209458B, ATMOSPHERE, EVAPORATION",

author = "L. Fossati and Haswell, {C. A.} and Froning, {C. S.} and L. Hebb and S. Holmes and U. Kolb and Ch. Helling and A. Carter and P. Wheatley and Cameron, {A. C.} and B. Loeillet and D. Pollacco and R. Street and Stempels, {H. C.} and E. Simpson and S. Udry and Joshi, {Y. C.} and West, {R. G.} and I. Skillen and D. Wilson",

year = "2010",

month = may,

day = "10",

doi = "10.1088/2041-8205/714/2/L222",

language = "English",

volume = "714",

pages = "L222--L227",

journal = "Astrophysical Journal Letters",

issn = "2041-8205",

publisher = "American Astronomical Society",

number = "2",

}

Fossati, L, Haswell, CA, Froning, CS, Hebb, L, Holmes, S, Kolb, U, Helling, C, Carter, A, Wheatley, P, Cameron, AC, Loeillet, B, Pollacco, D, Street, R, Stempels, HC, Simpson, E, Udry, S, Joshi, YC, West, RG, Skillen, I & Wilson, D 2010, 'Metals in the exosphere of the highly irradiated planet WASP-12b', Astrophysical Journal Letters, vol. 714, no. 2, pp. L222-L227. https://doi.org/10.1088/2041-8205/714/2/L222

TY - JOUR

T1 - Metals in the exosphere of the highly irradiated planet WASP-12b

AU - Fossati, L.

AU - Haswell, C. A.

AU - Froning, C. S.

AU - Hebb, L.

AU - Holmes, S.

AU - Kolb, U.

AU - Helling, Ch.

AU - Carter, A.

AU - Wheatley, P.

AU - Cameron, A. C.

AU - Loeillet, B.

AU - Pollacco, D.

AU - Street, R.

AU - Stempels, H. C.

AU - Simpson, E.

AU - Udry, S.

AU - Joshi, Y. C.

AU - West, R. G.

AU - Skillen, I.

AU - Wilson, D.

PY - 2010/5/10

Y1 - 2010/5/10

N2 - We present near-UV transmission spectroscopy of the highly irradiated transiting exoplanet WASP-12b, obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope. The spectra cover three distinct wavelength ranges: NUVA (2539-2580 angstrom), NUVB (2655-2696 angstrom), and NUVC (2770-2811 angstrom). Three independent methods all reveal enhanced transit depths attributable to absorption by resonance lines of metals in the exosphere of WASP-12b. Light curves of total counts in the NUVA and NUVC wavelength ranges show a detection at a 2.5 sigma level. We detect extra absorption in the Mg II lambda lambda 2800 resonance line cores at the 2.8 sigma level. The NUVA, NUVB, and NUVC light curves imply effective radii of 2.69 +/- 0.24 R-J, 2.18 +/- 0.18 R-J, and 2.66 +/- 0.22 R-J respectively, suggesting the planet is surrounded by an absorbing cloud which overfills the Roche lobe. We detect enhanced transit depths at the wavelengths of resonance lines of neutral sodium, tin, and manganese, and at singly ionized ytterbium, scandium, manganese, aluminum, vanadium, and magnesium. We also find the statistically expected number of anomalous transit depths at wavelengths not associated with any known resonance line. Our data are limited by photon noise, but taken as a whole the results are strong evidence for an extended absorbing exosphere surrounding the planet. The NUVA data exhibit an early ingress, contrary to model expectations; we speculate this could be due to the presence of a disk of previously stripped material.

AB - We present near-UV transmission spectroscopy of the highly irradiated transiting exoplanet WASP-12b, obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope. The spectra cover three distinct wavelength ranges: NUVA (2539-2580 angstrom), NUVB (2655-2696 angstrom), and NUVC (2770-2811 angstrom). Three independent methods all reveal enhanced transit depths attributable to absorption by resonance lines of metals in the exosphere of WASP-12b. Light curves of total counts in the NUVA and NUVC wavelength ranges show a detection at a 2.5 sigma level. We detect extra absorption in the Mg II lambda lambda 2800 resonance line cores at the 2.8 sigma level. The NUVA, NUVB, and NUVC light curves imply effective radii of 2.69 +/- 0.24 R-J, 2.18 +/- 0.18 R-J, and 2.66 +/- 0.22 R-J respectively, suggesting the planet is surrounded by an absorbing cloud which overfills the Roche lobe. We detect enhanced transit depths at the wavelengths of resonance lines of neutral sodium, tin, and manganese, and at singly ionized ytterbium, scandium, manganese, aluminum, vanadium, and magnesium. We also find the statistically expected number of anomalous transit depths at wavelengths not associated with any known resonance line. Our data are limited by photon noise, but taken as a whole the results are strong evidence for an extended absorbing exosphere surrounding the planet. The NUVA data exhibit an early ingress, contrary to model expectations; we speculate this could be due to the presence of a disk of previously stripped material.

KW - stars: individual (WASP-12)

KW - LINE-DATA-BASE

KW - RESONANCE-ABSORPTION LINES

KW - ENERGETIC NEUTRAL ATOMS

KW - EXOPLANET HD-209458B

KW - EXTRASOLAR PLANET

KW - WAVELENGTHS LONGWARD

KW - LYMAN LIMIT

KW - HD 209458B

KW - ATMOSPHERE

KW - EVAPORATION

U2 - 10.1088/2041-8205/714/2/L222

DO - 10.1088/2041-8205/714/2/L222

M3 - Article

SN - 2041-8205

VL - 714

SP - L222-L227

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

IS - 2

ER -

Metals in the exosphere of the highly irradiated planet WASP-12b

Abstract

Keywords

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Projects

Astrophysics in St Andrews: Astrophysics in St Andrews / SUPA (Continuan of Rolling Grant - XPP089

Wide Area Search for Planets: Project support for the Wide Area Search for Planets

Cite this