ترغب بنشر مسار تعليمي؟ اضغط هنا

WASP-86b and WASP-102b: super-dense versus bloated planets

82   0   0.0 ( 0 )
 نشر من قبل Francesca Faedi
 تاريخ النشر 2016
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

We report the discovery of two transiting planetary systems: a super dense, sub-Jupiter mass planet WASP-86b (mpl = 0.82 $pm$ 0.06 mj, rpl = 0.63 $pm$ 0.01 rj), and a bloated, Saturn-like planet WASP-102b (mpl = 0.62 $pm$ 0.04 mj, rpl=1.27 $pm$ 0.03 rj). They orbit their host star every $sim$5.03, and $sim$2.71 days, respectively. The planet hosting WASP-86 is a F7 star (teff = 6330$pm$110 K, feh = $+$0.23 $pm$ 0.14 dex, and age $sim$0.8--1~Gyr), WASP-102 is a G0 star (teff = 5940$pm$140 K, feh = $-$0.09$pm$ 0.19 dex, and age $sim$1~Gyr). These two systems highlight the diversity of planetary radii over similar masses for giant planets with masses between Saturn and Jupiter. WASP-102b shows a larger than model-predicted radius, indicating that the planet is receiving a strong incident flux which contributes to the inflation of its radius. On the other hand, with a density of $rho_{pl}$ = 3.24$pm$~0.3~$rho_{jup}$, WASP-86b is the densest gas giant planet among planets with masses in the range 0.05 $<M$_{pl}$<$ 2.0 mj. With a stellar mass of 1.34 M$_{odot}$ and feh = $+$0.23 dex, WASP-86 could host additional massive and dense planets given that its protoplanetary disc is expected to also have been enriched with heavy elements. In order to match WASP-86bs density, an extrapolation of theoretical models predicts a planet composition of more than 80% in heavy elements (whether confined in a core or mixed in the envelope). This fraction corresponds to a core mass of approximately 210me for WASP-86bs mass of mpl$sim$260,me. Only planets with masses larger than about 2mj have larger densities than that of WASP-86b, making it exceptional in its mass range.

قيم البحث

اقرأ أيضاً

We report three new transiting hot-Jupiter planets discovered from the WASP surveys combined with radial velocities from OHP/SOPHIE and Euler/CORALIE and photometry from Euler and TRAPPIST. All three planets are inflated, with radii 1.7-1.8 Rjup. All orbit hot stars, F5-F7, and all three stars have evolved, post-MS radii (1.7-2.2 Rsun). Thus the three planets, with orbits of 1.8-3.9 d, are among the most irradiated planets known. This reinforces the correlation between inflated planets and stellar irradiation.
We present three newly discovered sub-Jupiter mass planets from the SuperWASP survey: WASP-54b is a heavily bloated planet of mass 0.636$^{+0.025}_{-0.024}$ mj and radius 1.653$^{+0.090}_{-0.083}$ rj. It orbits a F9 star, evolving off the main sequen ce, every 3.69 days. Our MCMC fit of the system yields a slightly eccentric orbit ($e=0.067^{+0.033}_{-0.025}$) for WASP-54b. We investigated further the veracity of our detection of the eccentric orbit for WASP-54b, and we find that it could be real. However, given the brightness of WASP-54 V=10.42 magnitudes, we encourage observations of a secondary eclipse to draw robust conclusions on both the orbital eccentricity and the thermal structure of the planet. WASP-56b and WASP-57b have masses of 0.571$^{+0.034}_{-0.035}$ mj and $0.672^{+0.049}_{-0.046}$ mj, respectively; and radii of $1.092^{+0.035}_{-0.033}$ rj for WASP-56b and $0.916^{+0.017}_{-0.014}$ rj for WASP-57b. They orbit main sequence stars of spectral type G6 every 4.67 and 2.84 days, respectively. WASP-56b and WASP-57b show no radius anomaly and a high density possibly implying a large core of heavy elements; possibly as high as $sim$50 M$_{oplus}$ in the case of WASP-57b. However, the composition of the deep interior of exoplanets remain still undetermined. Thus, more exoplanet discoveries such as the ones presented in this paper, are needed to understand and constrain giant planets physical properties.
153 - Ch. Helling , D. Lewis , D. Samra 2021
Ultra-hot Jupiters are the hottest exoplanets discovered so far. Observations begin to provide insight into the composition of their extended atmospheres and their chemical day/night asymmetries. Both are strongly affected by cloud formation. We expl ore trends in cloud properties for a sample of five giant gas planets: WASP-43b, WASP-18b, HAT-P-7b, WASP-103b, and WASP-121b. This provides a reference frame for cloud properties for the JWST targets WASP-43b and WASP-121b. We further explore chemically inert tracers to observe geometrical asymmetries, and if the location of inner boundary of a 3D GCM matters for the clouds that form. The large day/night temperature differences of ultra-hot Jupiters cause large chemical asymmetries: cloud-free days but cloudy nights, atomic vs. molecular gases and respectively different mean molecular weights, deep thermal ionospheres vs. low-ionised atmospheres, undepleted vs enhanced C/O. WASP-18b, as the heaviest planet in the sample, has the lowest global C/O. The global climate may be considered as similar amongst ultra-hot Jupiters, but different to that of hot gas giants. The local weather, however, is individual for each planet since the local thermodynamic conditions, and hence the local cloud and gas properties, differ. The morning and the evening terminator of ultra-hot Jupiters will carry signatures of their strong chemical asymmetry such that ingress/egress asymmetries can be expected. An increased C/O ratio is a clear sign of cloud formation, making cloud modelling a necessity when utilizing C/O (or other mineral ratios) as tracer for planet formation. The changing geometrical extension of the atmosphere from the day to the nightside may be probed through chemically inert species like helium. Ultra-hot Jupiters are likely to develop deep atmospheric ionospheres which may impact the atmosphere dynamics through MHD processes.
We present the discovery of four new giant planets from WASP, three hot Jupiters and one bloated sub-Saturn mass planet; WASP-169b, WASP-171b, WASP-175b and WASP-182b. Besides the discovery photometry from wasp we use radial velocity measurements fro m CORALIE and HARPS as well as follow-up photometry from EulerCam, TRAPPIST-North and -South and SPECULOOS. WASP-169b is a low density Jupiter ($M=0.561 pm 0.061~mathrm{M_{Jup}}, R=1.304^{+0.150}_{-0.073} ~mathrm{R_{Jup}}$) orbiting a V=12.17 F8 sub-giant in a 5.611~day orbit. WASP-171b is a typical hot Jupiter ($M=1.084 pm 0.094~mathrm{M_{Jup}}, R=0.98^{+0.07}_{-0.04} ~mathrm{R_{Jup}}$, $P=3.82~mathrm{days}$) around a V=13.05 G0 star. We find a linear drift in the radial velocities of WASP-171 spanning 3.5 years, indicating the possibility of an additional outer planet or stellar companion. WASP-175b is an inflated hot Jupiter ($M=0.99 pm 0.13~mathrm{M_{Jup}}, R=1.208 pm 0.081 ~mathrm{R_{Jup}}$, $P=3.07~mathrm{days}$) around a V=12.04 F7 star, which possibly is part of a binary system with a star 7.9arcsec away. WASP-182b is a bloated sub-Saturn mass planet ($M=0.148 pm 0.011~mathrm{M_{Jup}}, R=0.850pm 0.030 ~mathrm{R_{Jup}}$) around a metal rich V=11.98 G5 star ([Fe/H]$=0.27 pm 0.11$). With a orbital period of $P=3.377~mathrm{days}$, it sits right in the apex of the sub-Jovian desert, bordering the upper- and lower edge of the desert in both the mass-period and radius-period plane. WASP-169b, WASP-175b and WASP-182b are promising targets for atmospheric characterisation through transmission spectroscopy, with expected transmission signals of 121, 150 and 264 ppm respectively.
We report the discovery of WASP-166b, a super-Neptune planet with a mass of 0.1 Mjup (1.9 Mnep) and a bloated radius of 0.63 Rjup. It transits a V = 9.36, F9V star in a 5.44-d orbit that is aligned with the stellar rotation axis (sky-projected obliqu ity angle lambda = 3 +/- 5 degrees). Variations in the radial-velocity measurements are likely the result of magnetic activity over a 12-d stellar rotation period. WASP-166b appears to be a rare object within the ``Neptune desert.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا