Abstract
We report the joint WASP/KELT discovery of WASP-167b/KELT-13b, a transiting hot Jupiter with a 2.02-d orbit around a V = 10.5, F1V star with Fe/H = 0.1 ± 0.1. The 1.5 R
Jup planet was ...confirmed by Doppler tomography of the stellar line profiles during transit. We place a limit of <8 M
Jup on its mass. The planet is in a retrograde orbit with a sky-projected spin–orbit angle of λ = −165° ± 5°. This is in agreement with the known tendency for orbits around hotter stars to be more likely to be misaligned. WASP-167/KELT-13 is one of the few systems where the stellar rotation period is less than the planetary orbital period. We find evidence of non-radial stellar pulsations in the host star, making it a δ-Scuti or γ-Dor variable. The similarity to WASP-33, a previously known hot-Jupiter host with pulsations, adds to the suggestion that close-in planets might be able to excite stellar pulsations.
ABSTRACT We report on the mass and distance measurements of two single-lens events from the 2015 Spitzer microlensing campaign. With both finite-source effect and microlens parallax measurements, we ...find that the lens of OGLE-2015-BLG-1268 is very likely a brown dwarf (BD). Assuming that the source star lies behind the same amount of dust as the Bulge red clump, we find the lens is a 45 7 BD at 5.9 1.0 kpc. The lens of of the second event, OGLE-2015-BLG-0763, is a 0.50 0.04 star at 6.9 1.0 kpc. We show that the probability to definitively measure the mass of isolated microlenses is dramatically increased once simultaneous ground- and space-based observations are conducted.
ABSTRACT We report the detection of a cold Neptune mplanet = 21 2 M⊕ orbiting a 0.38 M M dwarf lying 2.5-3.3 kpc toward the Galactic center as part of a campaign combining ground-based and Spitzer ...observations to measure the Galactic distribution of planets. This is the first time that the complex real-time protocols described by Yee et al., which aim to maximize planet sensitivity while maintaining sample integrity, have been carried out in practice. Multiple survey and follow up teams successfully combined their efforts within the framework of these protocols to detect this planet. This is the second planet in the Spitzer Galactic distribution sample. Both are in the near to mid-disk and are clearly not in the Galactic bulge.
We report 13 high-precision light curves of eight transits of the exoplanet WASP-52 b, obtained by using four medium-class telescopes, through different filters, and adopting the defocussing ...technique. One transit was recorded simultaneously from two different observatories and another one from the same site but with two different instruments, including a multiband camera. Anomalies were clearly detected in five light curves and modelled as star-spots occulted by the planet during the transit events. We fitted the clean light curves with the JKTEBOP code, and those with the anomalies with the PRISM+GEMC codes in order to simultaneously model the photometric parameters of the transits and the position, size and contrast of each star-spot. We used these new light curves and some from the literature to revise the physical properties of the WASP-52 system. Star-spots with similar characteristics were detected in four transits over a period of 43 d. In the hypothesis that we are dealing with the same star-spot, periodically occulted by the transiting planet, we estimated the projected orbital obliquity of WASP-52 b to be ... = 3 Math Processing Error...8 plus or minus 8 Math Processing Error...4. We also determined the true orbital obliquity, ... = 20... plus or minus 50..., which is, although very uncertain, the first measurement of ... purely from star-spot crossings. We finally assembled an optical transmission spectrum of the planet and searched for variations of its radius as a function of wavelength. Our analysis suggests a flat transmission spectrum within the experimental uncertainties. (ProQuest: ... denotes formulae/symbols omitted.)
We present 17 transit light curves of the ultrashort period planetary system WASP-103, a strong candidate for the detection of tidally-induced orbital decay. We use these to establish a ...high-precision reference epoch for transit timing studies. The time of the reference transit mid-point is now measured to an accuracy of 4.8 s, versus 67.4 s in the discovery paper, aiding future searches for orbital decay. With the help of published spectroscopic measurements and theoretical stellar models, we determine the physical properties of the system to high precision and present a detailed error budget for these calculations. The planet has a Roche lobe filling factor of 0.58, leading to a significant asphericity; we correct its measured mass and mean density for this phenomenon. A high-resolution Lucky Imaging observation shows no evidence for faint stars close enough to contaminate the point spread function of WASP-103. Our data were obtained in the Bessell RI and the SDSS griz passbands and yield a larger planet radius at bluer optical wavelengths, to a confidence level of 7.3σ. Interpreting this as an effect of Rayleigh scattering in the planetary atmosphere leads to a measurement of the planetary mass which is too small by a factor of 5, implying that Rayleigh scattering is not the main cause of the variation of radius with wavelength.
We report the discovery of OGLE-2016-BLG-1190Lb, which is likely to be the first Spitzer microlensing planet in the Galactic bulge/bar, an assignation that can be confirmed by two epochs of ...high-resolution imaging of the combined source-lens baseline object. The planet's mass, Mp = 13.4 0.9 MJ, places it right at the deuterium-burning limit, i.e., the conventional boundary between "planets" and "brown dwarfs." Its existence raises the question of whether such objects are really "planets" (formed within the disks of their hosts) or "failed stars" (low-mass objects formed by gas fragmentation). This question may ultimately be addressed by comparing disk and bulge/bar planets, which is a goal of the Spitzer microlens program. The host is a G dwarf, Mhost = 0.89 0.07 M , and the planet has a semimajor axis a ∼ 2.0 au. We use Kepler K2 Campaign 9 microlensing data to break the lens-mass degeneracy that generically impacts parallax solutions from Earth-Spitzer observations alone, which is the first successful application of this approach. The microlensing data, derived primarily from near-continuous, ultradense survey observations from OGLE, MOA, and three KMTNet telescopes, contain more orbital information than for any previous microlensing planet, but not quite enough to accurately specify the full orbit. However, these data do permit the first rigorous test of microlensing orbital-motion measurements, which are typically derived from data taken over <1% of an orbital period.
Relic galaxies are thought to be the progenitors of high-redshift red nuggets that for some reason missed the channels of size growth and evolved passively and undisturbed since the first star ...formation burst (at
z
> 2). These local ultracompact old galaxies are unique laboratories for studying the star formation processes at high redshift and thus the early stage of galaxy formation scenarios. Counterintuitively, theoretical and observational studies indicate that relics are more common in denser environments, where merging events predominate. To verify this scenario, we compared the number counts of a sample of ultracompact massive galaxies (UCMG
S
) selected within the third data release of the Kilo Degree Survey, that is, systems with sizes
R
e
< 1.5 kpc and stellar masses
M
⋆
> 8 × 10
10
M
⊙
, with the number counts of galaxies with the same masses but normal sizes in field and cluster environments. Based on their optical and near-infrared colors, these UCMG
S
are likely to be mainly old, and hence representative of the relic population. We find that both UCMG
S
and normal-size galaxies are more abundant in clusters and their relative fraction depends only mildly on the global environment, with denser environments penalizing the survival of relics. Hence, UCMG
S
(and likely relics overall) are not special because of the environment effect on their nurture, but rather they are just a product of the stochasticity of the merging processes regardless of the global environment in which they live.
ABSTRACT
Transits in the planetary system WASP-4 were recently found to occur 80 s earlier than expected in observations from the TESS satellite. We present 22 new times of mid-transit that confirm ...the existence of transit timing variations, and are well fitted by a quadratic ephemeris with period decay dP/dt = −9.2 ± 1.1 ms yr−1. We rule out instrumental issues, stellar activity, and the Applegate mechanism as possible causes. The light-time effect is also not favoured due to the non-detection of changes in the systemic velocity. Orbital decay and apsidal precession are plausible but unproven. WASP-4 b is only the third hot Jupiter known to show transit timing variations to high confidence. We discuss a variety of observations of this and other planetary systems that would be useful in improving our understanding of WASP-4 in particular and orbital decay in general.
Abstract
We present broad-band photometry of 11 planetary transits of the hot Jupiter WASP-74 b, using three medium-class telescopes and employing the telescope-defocusing technique. Most of the ...transits were monitored through I filters and one was simultaneously observed in five optical (U, g′, r′, i′, z′) and three near-infrared (J, H, K) passbands, for a total of 18 light curves. We also obtained new high-resolution spectra of the host star. We used these new data to review the orbital and physical properties of the WASP-74 planetary system. We were able to better constrain the main system characteristics, measuring smaller radius and mass for both the hot Jupiter and its host star than previously reported in the literature. Joining our optical data with those taken with the HST in the near infrared, we built up an observational transmission spectrum of the planet, which suggests the presence of strong optical absorbers, as TiO and VO gases, in its atmosphere.
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