- ID:
- ivo://CDS.VizieR/J/AJ/157/149
- Title:
- Transit parameters for planets around subgiants
- Short Name:
- J/AJ/157/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of seven new planets and eight planet candidates around subgiant stars, as additions to the known sample of planets around "retired A stars". Among these are the possible first three-planet systems around subgiant stars, HD 163607 and HD 4917. Additionally, we present calculations of possible transit times, durations, depths, and probabilities for all known planets around subgiant (3<logg<4) stars, focused on possible transits during the TESS mission. While most have transit probabilities of 1%-2%, we find that there are three planets with transit probabilities >9%.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/646/A183
- Title:
- Transit photometry of NGTS-14Ab
- Short Name:
- J/A+A/646/A183
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The sub-Jovian or Neptunian desert is a previously-identified region of parameter space where there is a relative dearth of intermediate- mass planets at short orbital periods. We present the discovery of a new transiting planetary system within the Neptunian desert, NGTS-14A. Transits of NGTS-14Ab were discovered in photometry from the Next Generation Transit Survey (NGTS). Follow-up transit photometry was conducted from several ground-based facilities, as well as extracted from TESS full- frame images. We combine radial velocities from the HARPS spectrograph with the photometry in a global analysis to determine the system parameters. NGTS-14Ab has a radius about 30 per cent larger than that of Neptune (0.444+/-0.030R_Jup_), and is around 70 per cent more massive than Neptune (0.092+/-0.012 M_Jup_). It transits the main-sequence K1 star, NGTS-14A, with a period of 3.54 days, just far enough to have maintained at least some of its primordial atmosphere. We have also identified a possible long-period stellar mass companion to the system, NGTS-14B.
- ID:
- ivo://CDS.VizieR/J/A+A/652/A117
- Title:
- Transit search in the V1400 Cen system
- Short Name:
- J/A+A/652/A117
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- In 2007, the young star 1SWASP J140747.93-394542.6 (V1400 Cen) underwent a complex series of deep eclipses over 56 days. This was attributed to the transit of a ring system filling a large fraction of the Hill sphere of an unseen substellar companion. Subsequent photometric monitoring has not found any other deep transits from this candidate ring system, but if there are more substellar companions and if they are coplanar with the potential ring system, there is a chance that they will transit the star as well. This young star is active, and the light curves show a 5% modulation in amplitude with a dominant rotation period of 3.2 days due to starspots rotating into and out of view. We model and remove the rotational modulation of the J1407 light curve and search for additional transit signatures of substellar companions orbiting around J1407. We combine the photometry of J1407 from several observatories, spanning a 19 year baseline. We remove the rotational modulation by modeling the variability as a periodic signal, whose periodicity changes slowly with time over several years due to the activity cycle of the star. A transit least squares (TLS) analysis is used to search for any periodic transiting signals within the cleaned light curve. We identify an activity cycle of J1407 with a period of 5.4yr. A TLS search does not find any plausible periodic eclipses in the light curve, from 1.2% amplitude at 5 days up to 1.9% at 20 days. This sensitivity is confirmed by injecting artificial transits into the light curve and determining the recovery fraction as a function of transit depth and orbital period. J1407 is confirmed as a young active star with an activity cycle consistent with a rapidly rotating solar mass star. With the rotational modulation removed, the TLS analysis reaches down to planetary mass radii for young exoplanets, ruling out transiting companions with radii larger than about 1R_Jup_.
- ID:
- ivo://CDS.VizieR/II/278
- Title:
- Transits observed in OGLE 2001-2003
- Short Name:
- II/278
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of an extensive photometric search for planetary and low-luminosity object transits in the Galactic disk stars commencing the third phase of the Optical Gravitational Lensing Experiment - OGLE-III.
- ID:
- ivo://CDS.VizieR/J/ApJ/888/L5
- Title:
- Transits, occultation times and RVs of WASP-12b
- Short Name:
- J/ApJ/888/L5
- Date:
- 25 Oct 2021 10:19:53
- Publisher:
- CDS
- Description:
- WASP-12b is a transiting hot Jupiter on a 1.09 day orbit around a late-F star. Since the planet's discovery in 2008, the time interval between transits has been decreasing by 29+/-2ms/yr. This is a possible sign of orbital decay, although the previously available data left open the possibility that the planet's orbit is slightly eccentric and is undergoing apsidal precession. Here, we present new transit and occultation observations that provide more decisive evidence for orbital decay, which is favored over apsidal precession by a {Delta}BIC of 22.3 or Bayes factor of 70000. We also present new radial-velocity data that rule out the Romer effect as the cause of the period change. This makes WASP-12 the first planetary system for which we can be confident that the orbit is decaying. The decay timescale for the orbit is P/{dot}P=3.25+/-0.23Myr. Interpreting the decay as the result of tidal dissipation, the modified stellar tidal quality factor is Q_*_^'^=1.8x10^5^.
22426. Transits of exoplanet XO-3b
- ID:
- ivo://CDS.VizieR/J/ApJ/683/1076
- Title:
- Transits of exoplanet XO-3b
- Short Name:
- J/ApJ/683/1076
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometry of 13 transits of XO-3b, a massive transiting planet on an eccentric orbit. Previous data led to two inconsistent estimates of the planetary radius. Our data strongly favor the smaller radius, with increased precision: R_p_=1.217+/-0.073R_{sun}_. A conflict remains between the mean stellar density determined from the light curve, and the stellar surface gravity determined from the shapes of spectral lines. We argue the light curve should take precedence, and revise the system parameters accordingly. The planetary radius is about 1{sigma} larger than the theoretical radius for a hydrogen-helium planet of the given mass and insolation. To help in planning future observations, we provide refined transit and occultation ephemerides.
22427. Transits of GJ 1214
- ID:
- ivo://CDS.VizieR/J/A+A/549/A10
- Title:
- Transits of GJ 1214
- Short Name:
- J/A+A/549/A10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 11 high-precision photometric transit observations of the transiting super-Earth planet GJ 1214 b. Combining these data with observations from other authors, we investigate the ephemeris for possible signs of transit timing variations (TTVs) using a Bayesian approach. The observations were obtained using telescope-defocusing techniques, and achieve a high precision with random errors in the photometry as low as 1 mmag per point. To investigate the possibility of TTVs in the light curve, we calculate the overall probability of a TTV signal using Bayesian methods.
- ID:
- ivo://CDS.VizieR/J/A+A/557/A30
- Title:
- Transits of HAT-P-16 and WASP-21
- Short Name:
- J/A+A/557/A30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first photometric follow-up of the transiting planet HAT-P-16 b, and new photometric observations of WASP-21 b, obtained simultaneously with two medium-class telescopes located in different countries, using the telescope defocussing technique. We modeled these and other published data in order to estimate the physical parameters of the two planetary systems.
- ID:
- ivo://CDS.VizieR/J/A+A/518/A25
- Title:
- Transits of HD40307b by Spitzer
- Short Name:
- J/A+A/518/A25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used Spitzer and its IRAC camera to search for the transit of the super-Earth HD 40307b. The hypothesis that the planet transits could not be firmly discarded from our first photometric monitoring of a transit window because of the uncertainty coming from the modeling of the photometric baseline. To obtain a firm result, two more transit windows were observed and a global Bayesian analysis of the three IRAC time series and the HARPS radial velocities was performed. Unfortunately, the hypothesis that the planet transited during the observed phase window is firmly rejected, while the probability that the planet does transit but that the eclipse was missed by our observations is nearly negligible (0.26%)
- ID:
- ivo://CDS.VizieR/J/A+A/509/A4
- Title:
- Transits of 12 new exoplanet candidates
- Short Name:
- J/A+A/509/A4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used VLT/VIMOS images in the V band to obtain light curves of extrasolar planetary transits OGLE-TR-111 and OGLE-TR-113, and candidate planetary transits: OGLE-TR-82, OGLE-TR-86, OGLE-TR-91, OGLE-TR-106, OGLE-TR-109, OGLE-TR-110, OGLE-TR-159, OGLE-TR-167, OGLE-TR-170, OGLE-TR-171. Using difference imaging photometry, we were able to achieve millimagnitude errors in the individual data points. We present the analysis of the data and the light curves, by measuring transit amplitudes and ephemerides, and by calculating geometrical parameters for some of the systems. We observed 9 OGLE objects at the predicted transit moments. Two other transits were shifted in time by a few hours. For another seven objects we expected to observe transits during the VIMOS run, but they were not detected. The stars OGLE-TR-111 and OGLE-TR-113 are probably the only OGLE objects in the observed sample to host planets, with the other objects being very likely eclipsing binaries or multiple systems. In this paper we also report on four new transiting candidates which we have found in the data.
