The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
A Jordan - One of the best experts on this subject based on the ideXlab platform.
-
hats 71b a Giant Planet transiting an m3 dwarf star in tess sector 1
The Astronomical Journal, 2020Co-Authors: G A Bakos, D Bayliss, J Bento, W Bhatti, R Brahm, Z Csubry, N Espinoza, J D Hartman, Th Henning, A JordanAbstract:We report the discovery of HATS-71b, a transiting Gas Giant Planet on a P = 3.7955 day orbit around aG = 15.35 mag M3 dwarf star. HATS-71 is the coolest Mdwarf star known to host a hot Jupiter. The loss of light during transits is 4.7%, more than in any other confirmed transiting Planet system. The Planet was identified as a candidate by the ground-based HATSouth transit survey. It was confirmed using ground-based photometry, spectroscopy, and imaging, as well as spacebased photometry from the NASA Transiting ExoPlanet Survey Satellite mission (TIC 234523599). Combining all of these data, and utilizing Gaia.DR2, we find that the Planet has a radius of 1.024 +/- 0.018 R-J and mass of 0.37 +/- 0.24 M-J (95% confidence upper limit of <0.80 M-J), while the star has a mass of 0.4861 +/- 0.0060 M-circle dot and a radius of 0.4783 +/- 0.0060 R-circle dot.
-
hats 71b a Giant Planet transiting an m3 dwarf star in tess sector 1
arXiv: Earth and Planetary Astrophysics, 2018Co-Authors: G A Bakos, D Bayliss, J Bento, W Bhatti, R Brahm, Z Csubry, N Espinoza, J D Hartman, Th Henning, A JordanAbstract:We report the discovery of HATS-71b, a transiting Gas Giant Planet on a P = 3.7955 day orbit around a G = 15.35 mag M3 dwarf star. HATS-71 is the coolest M dwarf star known to host a hot Jupiter. The loss of light during transits is 4.7%, more than any other confirmed transiting Planet system. The Planet was identified as a candidate by the ground-based HATSouth transit survey. It was confirmed using ground-based photometry, spectroscopy, and imaging, as well as space-based photometry from the NASA TESS mission (TIC 234523599). Combining all of these data, and utilizing Gaia DR2, we find that the Planet has a radius of $1.080 \pm 0.016 R_J$ and mass of $0.45 \pm 0.24 M_J$ (95% confidence upper limit of $0.81 M_J$ ), while the star has a mass of $0.569 \pm^{0.042}_{0.069}\,M_\odot$ and a radius of $0.5161\pm^{0.0053}_{0.0099}\,R_\odot$. The Gaia DR2 data show that HATS-71 lies near the binary main sequence in the Hertzsprung-Russell diagram, suggesting that there may be an unresolved stellar binary companion. All of the available data is well fitted by a model in which there is a secondary star of mass $0.24 M_\odot$, although we caution that at present there is no direct spectroscopic or imaging evidence for such a companion. Even if there does exist such a stellar companion, the radius and mass of the Planet would be only marginally different from the values we have calculated under the assumption that the star is single.
-
hats 6b a warm saturn transiting an early m dwarf star and a set of empirical relations for characterizing k and m dwarf Planet hosts
The Astronomical Journal, 2015Co-Authors: J D Hartman, G A Bakos, D Bayliss, R Brahm, A Jordan, L Mancini, K Penev, M RabusAbstract:We report the discovery by the HATSouth survey of HATS-6b, an extrasolar Planet transiting a V=15.2mag, i = 13.7mag M1V star with a mass of 0.57M⊙ and a radius of 0.57R⊙. HATS-6b has a period of P � 3.3253d, mass of Mp � 0.32MJ, radius of Rp � 1.00RJ, and zero-albedo equilibrium temperature of Teq = 712.8±5.1K. HATS-6 is one of the lowest mass stars known to host a close-in Gas Giant Planet, and its transits are among the deepest of any known transiting Planet system. We discuss the follow-up opportunities afforded by this system, noting that despite the faintness of the host star, it is expected to have the highest K-band S/N transmission spectrum among known Gas Giant Planets with Teq < 750K. In order to characterize the star we present a new set of empirical relations between the density, radius, mass, bolometric magnitude, and V , J, H and K-band bolometric corrections for main sequence stars with M < 0.80M⊙, or spectral types later than K5. These relations are calibrated using eclipsing binary components as well as members of resolved binary systems. We account for intrinsic scatter in the relations in a self-consistent manner. We show that from the transit-based stellar density alone it is possible to measure the mass and radius of a � 0.6M⊙ star to � 7% and � 2% precision, respectively. Incorporating additional information, such as the V K color, or an absolute magnitude, allows the precision to be improved by up to a factor of two. Subject headings: Planetary systems — stars: individual (HATS-6) techniques: spectroscopic, photometric
-
hats 6b a warm saturn transiting an early m dwarf star and a set of empirical relations for characterizing k and m dwarf Planet hosts
arXiv: Earth and Planetary Astrophysics, 2014Co-Authors: J D Hartman, G A Bakos, D Bayliss, R Brahm, A Jordan, L Mancini, K Penev, M RabusAbstract:We report the discovery by the HATSouth survey of HATS-6b, an extrasolar Planet transiting a V=15.2 mag, i=13.7 mag M1V star with a mass of 0.57 Msun and a radius of 0.57 Rsun. HATS-6b has a period of P = 3.3253 d, mass of Mp=0.32 Mjup, radius of Rp=1.00 Rjup, and zero-albedo equilibrium temperature of Teq=712.8+-5.1 K. HATS-6 is one of the lowest mass stars known to host a close-in Gas Giant Planet, and its transits are among the deepest of any known transiting Planet system. We discuss the follow-up opportunities afforded by this system, noting that despite the faintness of the host star, it is expected to have the highest K-band S/N transmission spectrum among known Gas Giant Planets with Teq < 750 K. In order to characterize the star we present a new set of empirical relations between the density, radius, mass, bolometric magnitude, and V, J, H and K-band bolometric corrections for main sequence stars with M < 0.80 Msun, or spectral types later than K5. These relations are calibrated using eclipsing binary components as well as members of resolved binary systems. We account for intrinsic scatter in the relations in a self-consistent manner. We show that from the transit-based stellar density alone it is possible to measure the mass and radius of a ~0.6 Msun star to ~7% and ~2% precision, respectively. Incorporating additional information, such as the V-K color, or an absolute magnitude, allows the precision to be improved by up to a factor of two.
Collier A Cameron - One of the best experts on this subject based on the ideXlab platform.
-
line profile tomography of exoPlanet transits ii a Gas Giant Planet transiting a rapidly rotating a5 star
Monthly Notices of the Royal Astronomical Society, 2010Co-Authors: Collier A Cameron, E W Guenther, B Smalley, Iain Mcdonald, Leslie Hebb, J Andersen, T Augusteijn, S C C Barros, D J A Brown, William D CochranAbstract:Most of our knowledge of extrasolar Planets rests on precise radial-velocity measurements, either for direct detection or for confirmation of the Planetary origin of photometric transit signals. This has limited our exploration of the parameter space of exoPlanet hosts to solar- and later-type, sharp-lined stars. Here we extend the realm of stars with known Planetary companions to include hot, fast-rotating stars. Planet-like transits have previously been reported in the light curve obtained by the SuperWASP survey of the A5 star HD 15082 (WASP–33; V= 8.3, v sin i= 86 km s−1). Here we report further photometry and time-series spectroscopy through three separate transits, which we use to confirm the existence of a Gas-Giant Planet with an orbital period of 1.22 d in orbit around HD 15082. From the photometry and the properties of the Planet signal travelling through the spectral line profiles during the transit, we directly derive the size of the Planet, the inclination and obliquity of its orbital plane and its retrograde orbital motion relative to the spin of the star. This kind of analysis opens the way to studying the formation of Planets around a whole new class of young, early-type stars, hence under different physical conditions and generally in an earlier stage of formation than in sharp-lined late-type stars. The reflex orbital motion of the star caused by the transiting Planet is small, yielding an upper mass limit of 4.1 MJupiter on the Planet. We also find evidence of a third body of substellar mass in the system, which may explain the unusual orbit of the transiting Planet. In HD 15082, the stellar line profiles also show evidence of non-radial pulsations, clearly distinct from the Planetary transit signal. This raises the intriguing possibility that tides raised by the close-in Planet may excite or amplify the pulsations in such stars.
-
line profile tomography of exoPlanet transits ii a Gas Giant Planet transiting a rapidly rotating a5 star
arXiv: Earth and Planetary Astrophysics, 2010Co-Authors: Collier A Cameron, E W Guenther, B Smalley, Iain Mcdonald, Leslie Hebb, J Andersen, T Augusteijn, S C C Barros, D J A Brown, William D CochranAbstract:Most of our knowledge of extrasolar Planets rests on precise radial-velocity measurements, either for direct detection or for confirmation of the Planetary origin of photometric transit signals. This has limited our exploration of the parameter space of exoPlanet hosts to solar- and later-type, sharp-lined stars. Here we extend the realm of stars with known Planetary companions to include hot, fast-rotating stars. Planet-like transits have previously been reported in the lightcurve obtained by the SuperWASP survey of the A5 star HD15082 (WASP-33; V=8.3, v sin i = 86 km/sec). Here we report further photometry and time-series spectroscopy through three separate transits, which we use to confirm the existence of a Gas Giant Planet with an orbital period of 1.22d in orbit around HD15082. From the photometry and the properties of the Planet signal travelling through the spectral line profiles during the transit we directly derive the size of the Planet, the inclination and obliquity of its orbital plane, and its retrograde orbital motion relative to the spin of the star. This kind of analysis opens the way to studying the formation of Planets around a whole new class of young, early-type stars, hence under different physical conditions and generally in an earlier stage of formation than in sharp-lined late-type stars. The reflex orbital motion of the star caused by the transiting Planet is small, yielding an upper mass limit of 4.1 Jupiter masses on the Planet. We also find evidence of a third body of sub-stellar mass in the system, which may explain the unusual orbit of the transiting Planet. In HD 15082, the stellar line profiles also show evidence of non-radial pulsations, clearly distinct from the Planetary transit signal. This raises the intriguing possibility that tides raised by the close-in Planet may excite or amplify the pulsations in such stars.
-
wasp 10b a 3mj Gas Giant Planet transiting a late type k star
Monthly Notices of the Royal Astronomical Society, 2009Co-Authors: Collier A Cameron, D Pollacco, I Skillen, N P Gibson, D J Christian, E K Simpson, R A Street, Y C JoshiAbstract:We report the discovery of WASP-10b, a new transiting extrasolar Planet (ESP) discovered by the WASP Consortium and confirmed using NOT FIES and SOPHIE radial velocity data. A 3.09 day period, 29 mmag transit depth, and 2.36 hour duration are derived for WASP-10b using WASP and high precision photometric observations. Simultaneous fitting to the photometric and radial velocity data using a Markov-chain Monte Carlo procedure leads to a Planet radius of 1.28RJ, a mass of 2.96MJ and eccentricity of �0.06. WASP-10b is one of the more massive transiting ESPs, and we compare its characteristics to the current sample of transiting ESP, where there is currently little information for masses greater than �2MJ and non-zero eccentricities. WASP-10’s host star, GSC 2752-00114 (USNO-B1.0 1214-0586164) is among the fainter stars in the WASP sample, with V=12.7 and a spectral type of K5. This result shows promise for future late-type dwarf star surveys.
-
wasp 10b a 3m_j eccentric transiting Gas Giant Planet
2008Co-Authors: D J Christian, Collier A Cameron, D Pollacco, I Skillen, H C Stempels, N P Gibson, E K Simpson, R A Street, C A Haswell, K HorneAbstract:We report the discovery of WASP-10b, a new transiting extrasolar Planet (ESP) discovered by the WASP Consortium and confirmed using NOT FIES and SOPHIE radial velocity data. A 3.09 day period, 29 mmag transit depth, and 2.36 hour duration are derived for WASP-10b using WASP and high precision photometric observations. Simultaneous fitting to the photometric and radial velocity data using a Markov-chain Monte Carlo procedure leads to a Planet radius of 1.28R_J, a mass of 2.96M_J and eccentricity of ~0.06. WASP-10b is one of the more massive transiting ESPs, and we compare its characteristics to the current sample of transiting ESP, where there is currently little information for masses greater than ~2M_J and non-zero eccentricities. WASP-10's host star, GSC 2752-00114 (USNO-B1.0 1214-0586164) is among the fainter stars in the WASP sample, with V=12.7 and a spectral type of K5. This result shows promise for future late-type dwarf star surveys.
-
wasp 10b a 3m_j Gas Giant Planet transiting a late type k star
arXiv: Astrophysics, 2008Co-Authors: D J Christian, Collier A Cameron, D Pollacco, I Skillen, N P Gibson, Y C Joshi, E K Simpson, R A Street, F P Keenan, H C StempelsAbstract:We report the discovery of WASP-10b, a new transiting extrasolar Planet (ESP) discovered by the WASP Consortium and confirmed using NOT FIES and SOPHIE radial velocity data. A 3.09 day period, 29 mmag transit depth, and 2.36 hour duration are derived for WASP-10b using WASP and high precision photometric observations. Simultaneous fitting to the photometric and radial velocity data using a Markov-chain Monte Carlo procedure leads to a Planet radius of 1.28R_J, a mass of 2.96M_J and eccentricity of ~0.06. WASP-10b is one of the more massive transiting ESPs, and we compare its characteristics to the current sample of transiting ESP, where there is currently little information for masses greater than ~2M_J and non-zero eccentricities. WASP-10's host star, GSC 2752-00114 (USNO-B1.0 1214-0586164) is among the fainter stars in the WASP sample, with V=12.7 and a spectral type of K5. This result shows promise for future late-type dwarf star surveys.
J D Hartman - One of the best experts on this subject based on the ideXlab platform.
-
hats 71b a Giant Planet transiting an m3 dwarf star in tess sector 1
The Astronomical Journal, 2020Co-Authors: G A Bakos, D Bayliss, J Bento, W Bhatti, R Brahm, Z Csubry, N Espinoza, J D Hartman, Th Henning, A JordanAbstract:We report the discovery of HATS-71b, a transiting Gas Giant Planet on a P = 3.7955 day orbit around aG = 15.35 mag M3 dwarf star. HATS-71 is the coolest Mdwarf star known to host a hot Jupiter. The loss of light during transits is 4.7%, more than in any other confirmed transiting Planet system. The Planet was identified as a candidate by the ground-based HATSouth transit survey. It was confirmed using ground-based photometry, spectroscopy, and imaging, as well as spacebased photometry from the NASA Transiting ExoPlanet Survey Satellite mission (TIC 234523599). Combining all of these data, and utilizing Gaia.DR2, we find that the Planet has a radius of 1.024 +/- 0.018 R-J and mass of 0.37 +/- 0.24 M-J (95% confidence upper limit of <0.80 M-J), while the star has a mass of 0.4861 +/- 0.0060 M-circle dot and a radius of 0.4783 +/- 0.0060 R-circle dot.
-
hats 71b a Giant Planet transiting an m3 dwarf star in tess sector 1
arXiv: Earth and Planetary Astrophysics, 2018Co-Authors: G A Bakos, D Bayliss, J Bento, W Bhatti, R Brahm, Z Csubry, N Espinoza, J D Hartman, Th Henning, A JordanAbstract:We report the discovery of HATS-71b, a transiting Gas Giant Planet on a P = 3.7955 day orbit around a G = 15.35 mag M3 dwarf star. HATS-71 is the coolest M dwarf star known to host a hot Jupiter. The loss of light during transits is 4.7%, more than any other confirmed transiting Planet system. The Planet was identified as a candidate by the ground-based HATSouth transit survey. It was confirmed using ground-based photometry, spectroscopy, and imaging, as well as space-based photometry from the NASA TESS mission (TIC 234523599). Combining all of these data, and utilizing Gaia DR2, we find that the Planet has a radius of $1.080 \pm 0.016 R_J$ and mass of $0.45 \pm 0.24 M_J$ (95% confidence upper limit of $0.81 M_J$ ), while the star has a mass of $0.569 \pm^{0.042}_{0.069}\,M_\odot$ and a radius of $0.5161\pm^{0.0053}_{0.0099}\,R_\odot$. The Gaia DR2 data show that HATS-71 lies near the binary main sequence in the Hertzsprung-Russell diagram, suggesting that there may be an unresolved stellar binary companion. All of the available data is well fitted by a model in which there is a secondary star of mass $0.24 M_\odot$, although we caution that at present there is no direct spectroscopic or imaging evidence for such a companion. Even if there does exist such a stellar companion, the radius and mass of the Planet would be only marginally different from the values we have calculated under the assumption that the star is single.
-
hats 6b a warm saturn transiting an early m dwarf star and a set of empirical relations for characterizing k and m dwarf Planet hosts
The Astronomical Journal, 2015Co-Authors: J D Hartman, G A Bakos, D Bayliss, R Brahm, A Jordan, L Mancini, K Penev, M RabusAbstract:We report the discovery by the HATSouth survey of HATS-6b, an extrasolar Planet transiting a V=15.2mag, i = 13.7mag M1V star with a mass of 0.57M⊙ and a radius of 0.57R⊙. HATS-6b has a period of P � 3.3253d, mass of Mp � 0.32MJ, radius of Rp � 1.00RJ, and zero-albedo equilibrium temperature of Teq = 712.8±5.1K. HATS-6 is one of the lowest mass stars known to host a close-in Gas Giant Planet, and its transits are among the deepest of any known transiting Planet system. We discuss the follow-up opportunities afforded by this system, noting that despite the faintness of the host star, it is expected to have the highest K-band S/N transmission spectrum among known Gas Giant Planets with Teq < 750K. In order to characterize the star we present a new set of empirical relations between the density, radius, mass, bolometric magnitude, and V , J, H and K-band bolometric corrections for main sequence stars with M < 0.80M⊙, or spectral types later than K5. These relations are calibrated using eclipsing binary components as well as members of resolved binary systems. We account for intrinsic scatter in the relations in a self-consistent manner. We show that from the transit-based stellar density alone it is possible to measure the mass and radius of a � 0.6M⊙ star to � 7% and � 2% precision, respectively. Incorporating additional information, such as the V K color, or an absolute magnitude, allows the precision to be improved by up to a factor of two. Subject headings: Planetary systems — stars: individual (HATS-6) techniques: spectroscopic, photometric
-
hats 6b a warm saturn transiting an early m dwarf star and a set of empirical relations for characterizing k and m dwarf Planet hosts
arXiv: Earth and Planetary Astrophysics, 2014Co-Authors: J D Hartman, G A Bakos, D Bayliss, R Brahm, A Jordan, L Mancini, K Penev, M RabusAbstract:We report the discovery by the HATSouth survey of HATS-6b, an extrasolar Planet transiting a V=15.2 mag, i=13.7 mag M1V star with a mass of 0.57 Msun and a radius of 0.57 Rsun. HATS-6b has a period of P = 3.3253 d, mass of Mp=0.32 Mjup, radius of Rp=1.00 Rjup, and zero-albedo equilibrium temperature of Teq=712.8+-5.1 K. HATS-6 is one of the lowest mass stars known to host a close-in Gas Giant Planet, and its transits are among the deepest of any known transiting Planet system. We discuss the follow-up opportunities afforded by this system, noting that despite the faintness of the host star, it is expected to have the highest K-band S/N transmission spectrum among known Gas Giant Planets with Teq < 750 K. In order to characterize the star we present a new set of empirical relations between the density, radius, mass, bolometric magnitude, and V, J, H and K-band bolometric corrections for main sequence stars with M < 0.80 Msun, or spectral types later than K5. These relations are calibrated using eclipsing binary components as well as members of resolved binary systems. We account for intrinsic scatter in the relations in a self-consistent manner. We show that from the transit-based stellar density alone it is possible to measure the mass and radius of a ~0.6 Msun star to ~7% and ~2% precision, respectively. Incorporating additional information, such as the V-K color, or an absolute magnitude, allows the precision to be improved by up to a factor of two.
-
hat p 12b a low density sub saturn mass Planet transiting a metal poor k dwarf
The Astrophysical Journal, 2009Co-Authors: J D Hartman, G A Bakos, Guillermo Torres, G Kovacs, R W Noyes, A Pal, D W Latham, B SipőczAbstract:We report on the discovery of HAT-P-12b, a transiting extrasolar Planet orbiting the moderately bright V ≈ 12.8 K4 dwarf GSC 03033 – 00706, with a period P = 3.2130598 ± 0.0000021 d, transit epoch T_c = 2454419.19556 ± 0.00020 (BJD), and transit duration 0.0974 ± 0.0006 d. The host star has a mass of 0.73 ± 0.02 M_☉, radius of 0.70^(+0.02)_(–0.01) R_☉, effective temperature 4650 ± 60 K, and metallicity [Fe/H] = –0.29 ± 0.05. We find a slight correlation between the observed spectral line bisector spans and the radial velocity, so we consider, and rule out, various blend configurations including a blend with a background eclipsing binary, and hierarchical triple systems where the eclipsing body is a star or a Planet. We conclude that a model consisting of a single star with a transiting Planet best fits the observations, and show that a likely explanation for the apparent correlation is contamination from scattered moonlight. Based on this model, the Planetary companion has a mass of 0.211 ± 0.012 M_J and radius of 0.959^(+0.029)_(–0.021) R_J yielding a mean density of 0.295 ± 0.025 g cm^(–3). Comparing these observations with recent theoretical models, we find that HAT-P-12b is consistent with a ~1-4.5 Gyr, mildly irradiated, H/He-dominated Planet with a core mass M_C ≾ 10 M_⊕. HAT-P-12b is thus the least massive H/He-dominated Gas Giant Planet found to date. This record was previously held by Saturn.
Mark J. Veyette - One of the best experts on this subject based on the ideXlab platform.
-
The transit transmission spectrum of a cold Gas Giant Planet
The Astrophysical Journal, 2015Co-Authors: Paul A. Dalba, Philip S. Muirhead, Matthew M. Hedman, Jonathan J. Fortney, Philip D. Nicholson, Mark J. VeyetteAbstract:© 2015. The American Astronomical Society. All rights reserved.. We use solar occultations observed by the Visual and Infrared Mapping Spectrometer on board the Cassini Spacecraft to extract the 1-5 μm transmission spectrum of Saturn, as if it were a transiting exoPlanet. We detect absorption from methane, ethane, acetylene, aliphatic hydrocarbons, and possibly carbon monoxide, with peak-to-peak features of up to 90 parts-per-million despite the presence of ammonia clouds. We also find that atmospheric refraction, as opposed to clouds or haze, determines the minimum altitude that could be probed during mid-transit. Self-consistent exoPlanet atmosphere models show good agreement with Saturn's transmission spectrum but fail to reproduce a large absorption feature near 3.4 μm, likely caused by Gaseous ethane and a C-H stretching mode of an unknown aliphatic hydrocarbon. This large feature is located in one of the Spitzer Space Telescope bandpasses and could alter interpretations of transmission spectra if not properly modeled. The large signal in Saturn's transmission spectrum suggests that transmission spectroscopy of cold, long-period Gaseous exoPlanets should be possible with current and future observatories. Motivated by these results, we briefly consider the feasibility of using a survey to search for and characterize cold exoPlanets that are analogous to Jupiter and Saturn utilizing a target-of-opportunity approach.
-
the transit transmission spectrum of a cold Gas Giant Planet
arXiv: Earth and Planetary Astrophysics, 2015Co-Authors: Paul A. Dalba, Philip S. Muirhead, Matthew M. Hedman, Jonathan J. Fortney, Philip D. Nicholson, Mark J. VeyetteAbstract:We use solar occultations observed by the Visual and Infrared Mapping Spectrometer aboard the Cassini Spacecraft to extract the 1 to 5 micron transmission spectrum of Saturn, as if it were a transiting exoPlanet. We detect absorption from methane, ethane, acetylene, aliphatic hydrocarbons, and possibly carbon monoxide with peak-to-peak features of up to 90 parts-per-million despite the presence of ammonia clouds. We also find that atmospheric refraction, as opposed to clouds or haze, determines the minimum altitude that could be probed during mid-transit. Self-consistent exoPlanet atmosphere models show good agreement with Saturn's transmission spectrum but fail to reproduce a large absorption feature near 3.4 microns likely caused by Gaseous ethane and a C-H stretching mode of an unknown aliphatic hydrocarbon. This large feature is located in one of the Spitzer Space Telescope bandpasses and could alter interpretations of transmission spectra if not properly modeled. The large signal in Saturn's transmission spectrum suggests that transmission spectroscopy of cold, long-period Gaseous exoPlanets should be possible with current and future observatories. Motivated by these results, we briefly consider the feasibility of a survey to search for and characterize cold exoPlanets analogous to Jupiter and Saturn using a target-of-opportunity approach.
Jonathan J. Fortney - One of the best experts on this subject based on the ideXlab platform.
-
The transit transmission spectrum of a cold Gas Giant Planet
The Astrophysical Journal, 2015Co-Authors: Paul A. Dalba, Philip S. Muirhead, Matthew M. Hedman, Jonathan J. Fortney, Philip D. Nicholson, Mark J. VeyetteAbstract:© 2015. The American Astronomical Society. All rights reserved.. We use solar occultations observed by the Visual and Infrared Mapping Spectrometer on board the Cassini Spacecraft to extract the 1-5 μm transmission spectrum of Saturn, as if it were a transiting exoPlanet. We detect absorption from methane, ethane, acetylene, aliphatic hydrocarbons, and possibly carbon monoxide, with peak-to-peak features of up to 90 parts-per-million despite the presence of ammonia clouds. We also find that atmospheric refraction, as opposed to clouds or haze, determines the minimum altitude that could be probed during mid-transit. Self-consistent exoPlanet atmosphere models show good agreement with Saturn's transmission spectrum but fail to reproduce a large absorption feature near 3.4 μm, likely caused by Gaseous ethane and a C-H stretching mode of an unknown aliphatic hydrocarbon. This large feature is located in one of the Spitzer Space Telescope bandpasses and could alter interpretations of transmission spectra if not properly modeled. The large signal in Saturn's transmission spectrum suggests that transmission spectroscopy of cold, long-period Gaseous exoPlanets should be possible with current and future observatories. Motivated by these results, we briefly consider the feasibility of using a survey to search for and characterize cold exoPlanets that are analogous to Jupiter and Saturn utilizing a target-of-opportunity approach.
-
the transit transmission spectrum of a cold Gas Giant Planet
arXiv: Earth and Planetary Astrophysics, 2015Co-Authors: Paul A. Dalba, Philip S. Muirhead, Matthew M. Hedman, Jonathan J. Fortney, Philip D. Nicholson, Mark J. VeyetteAbstract:We use solar occultations observed by the Visual and Infrared Mapping Spectrometer aboard the Cassini Spacecraft to extract the 1 to 5 micron transmission spectrum of Saturn, as if it were a transiting exoPlanet. We detect absorption from methane, ethane, acetylene, aliphatic hydrocarbons, and possibly carbon monoxide with peak-to-peak features of up to 90 parts-per-million despite the presence of ammonia clouds. We also find that atmospheric refraction, as opposed to clouds or haze, determines the minimum altitude that could be probed during mid-transit. Self-consistent exoPlanet atmosphere models show good agreement with Saturn's transmission spectrum but fail to reproduce a large absorption feature near 3.4 microns likely caused by Gaseous ethane and a C-H stretching mode of an unknown aliphatic hydrocarbon. This large feature is located in one of the Spitzer Space Telescope bandpasses and could alter interpretations of transmission spectra if not properly modeled. The large signal in Saturn's transmission spectrum suggests that transmission spectroscopy of cold, long-period Gaseous exoPlanets should be possible with current and future observatories. Motivated by these results, we briefly consider the feasibility of a survey to search for and characterize cold exoPlanets analogous to Jupiter and Saturn using a target-of-opportunity approach.
-
spitzer secondary eclipse observations of five cool Gas Giant Planets and empirical trends in cool Planet emission spectra
The Astrophysical Journal, 2015Co-Authors: Jonathan J. Fortney, Heather A Knutson, Drake Deming, Joshua A. Kammer, Michael R Line, Adam Burrows, Nicolas B Cowan, A H M J Triaud, Eric AgolAbstract:In this work we present Spitzer 3.6 and 4.5 μm secondary eclipse observations of five new cool (<1200 K) transiting Gas Giant Planets: HAT-P-19b, WASP-6b, WASP-10b, WASP-39b, and WASP-67b. We compare our measured eclipse depths to the predictions of a suite of atmosphere models and to eclipse depths for Planets with previously published observations in order to constrain the temperature- and mass-dependent properties of Gas Giant Planet atmospheres. We find that the dayside emission spectra of Planets less massive than Jupiter require models with efficient circulation of energy to the night side and/or increased albedos, while those with masses greater than that of Jupiter are consistently best-matched by models with inefficient circulation and low albedos. At these relatively low temperatures we expect the atmospheric CH_4/CO ratio to vary as a function of metallicity, and we therefore use our observations of these Planets to constrain their atmospheric metallicities. We find that the most massive Planets have dayside emission spectra that are best-matched by solar metallicity atmosphere models, but we are not able to place strong constraints on metallicities of the smaller Planets in our sample. Interestingly, we find that the ratio of the 3.6 and 4.5 μm brightness temperatures for these cool transiting Planets is independent of Planet temperature, and instead exhibits a tentative correlation with Planet mass. If this trend can be confirmed, it would suggest that the shape of these Planets' emission spectra depends primarily on their masses, consistent with the hypothesis that lower-mass Planets are more likely to have metal-rich atmospheres.
-
spitzer secondary eclipse observations of five cool Gas Giant Planets and empirical trends in cool Planet emission spectra
arXiv: Earth and Planetary Astrophysics, 2015Co-Authors: Jonathan J. Fortney, Heather A Knutson, Drake Deming, Joshua A. Kammer, Michael R Line, Adam Burrows, Nicolas B Cowan, A H M J Triaud, Eric AgolAbstract:In this work we present Spitzer 3.6 and 4.5 micron secondary eclipse observations of five new cool (<1200 K) transiting Gas Giant Planets: HAT-P-19b, WASP-6b, WASP-10b, WASP-39b, and WASP-67b. We compare our measured eclipse depths to the predictions of a suite of atmosphere models and to eclipse depths for Planets with previously published observations in order to constrain the temperature- and mass-dependent properties of Gas Giant Planet atmospheres. We find that the dayside emission spectra of Planets less massive than Jupiter require models with efficient circulation of energy to the night side and/or increased albedos, while those with masses greater than that of Jupiter are consistently best-matched by models with inefficient circulation and low albedos. At these relatively low temperatures we expect the atmospheric methane to CO ratio to vary as a function of metallicity, and we therefore use our observations of these Planets to constrain their atmospheric metallicities. We find that the most massive Planets have dayside emission spectra that are best-matched by solar metallicity atmosphere models, but we are not able to place strong constraints on metallicities of the smaller Planets in our sample. Interestingly, we find that the ratio of the 3.6 and 4.5 micron brightness temperatures for these cool transiting Planets is independent of Planet temperature, and instead exhibits a tentative correlation with Planet mass. If this trend can be confirmed, it would suggest that the shape of these Planets' emission spectra depends primarily on their masses, consistent with the hypothesis that lower-mass Planets are more likely to have metal-rich atmospheres.
-
the roles of tidal evolution and evaporative mass loss in the origin of corot 7 b
arXiv: Earth and Planetary Astrophysics, 2010Co-Authors: Brian Jackson, Jonathan J. Fortney, Neil Miller, Rory Barnes, Sean N Raymond, R GreenbergAbstract:CoRoT-7 b is the first confirmed rocky exoPlanet, but, with an orbital semi-major axis of 0.0172 AU, its origins may be unlike any rocky Planet in our solar system. In this study, we consider the roles of tidal evolution and evaporative mass loss in CoRoT-7 b's history, which together have modified the Planet's mass and orbit. If CoRoT-7 b has always been a rocky body, evaporation may have driven off almost half its original mass, but the mass loss may depend sensitively on the extent of tidal decay of its orbit. As tides caused CoRoT-7 b's orbit to decay, they brought the Planet closer to its host star, thereby enhancing the mass loss rate. Such a large mass loss also suggests the possibility that CoRoT-7 b began as a Gas Giant Planet and had its original atmosphere completely evaporated. In this case, we find that CoRoT-7 b's original mass probably didn't exceed 200 Earth masses (about 2/3 of a Jupiter mass). Tides raised on the host star by the Planet may have significantly reduced the orbital semi-major axis, perhaps causing the Planet to migrate through mean-motion resonances with the other Planet in the system, CoRoT-7 c. The coupling between tidal evolution and mass loss may be important not only for CoRoT-7 b but also for other close-in exoPlanets, and future studies of mass loss and orbital evolution may provide insight into the origin and fate of close-in Planets, both rocky and Gaseous.
