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- ID:
- ivo://CDS.VizieR/J/A+A/575/A111
- Title:
- GAPS V: Global analysis of the XO-2 system
- Short Name:
- J/A+A/575/A111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- XO-2 is the first confirmed wide stellar binary system where the almost twin components XO-2N and XO-2S have planets, and it is a peculiar laboratory in which to investigate the diversity of planetary systems. This stimulated a detailed characterization study of the stellar and planetary components based on new observations. We collected high-resolution spectra with the HARPS-N spectrograph and multi-band light curves. Spectral analysis led to an accurate determination of the stellar atmospheric parameters and characterization of the stellar activity, and high-precision radial velocities of XO-2N were measured. We collected 14 transit light curves of XO-2Nb used to improve the transit parameters. Photometry provided accurate magnitude differences between the stars and a measure of their rotation periods.
- ID:
- ivo://CDS.VizieR/J/ApJ/670/1367
- Title:
- Gemini Deep Planet Survey
- Short Name:
- J/ApJ/670/1367
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the Gemini Deep Planet Survey, a near-infrared adaptive optics search for giant planets and brown dwarfs around 85 nearby young stars. The observations were obtained with the Altair adaptive optics system at the Gemini North telescope, and angular differential imaging was used to suppress the speckle noise of the central star. Typically, the observations are sensitive to angular separations beyond 0.5" with 5{sigma} contrast sensitivities in magnitude difference at 1.6um of 9.5 at 0.5", 12.9 at 1", 15.0 at 2", and 16.5 at 5". These sensitivities are sufficient to detect planets more massive than 2M_{Jup}_ with a projected separation in the range 40-200AU around a typical target. Second-epoch observations of 48 stars with candidates (out of 54) have confirmed that all candidates are unrelated background stars. A detailed statistical analysis of the survey results is presented.
- ID:
- ivo://CDS.VizieR/J/ApJ/767/94
- Title:
- 1.1-1.9GHz SETI survey of KOIs. I.
- Short Name:
- J/ApJ/767/94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a targeted search for narrow-band (<5Hz) drifting sinusoidal radio emission from 86 stars in the Kepler field hosting confirmed or candidate exoplanets. Radio emission less than 5Hz in spectral extent is currently known to only arise from artificial sources. The stars searched were chosen based on the properties of their putative exoplanets, including stars hosting candidates with 380K>T_eq_>230K, stars with five or more detected candidates or stars with a super-Earth (R_p_<3R_{earth}_) in a >50 day orbit. Baseband voltage data across the entire band between 1.1 and 1.9GHz were recorded at the Robert C. Byrd Green Bank Telescope between 2011 February and April and subsequently searched offline. No signals of extraterrestrial origin were found. We estimate that fewer than ~1% of transiting exoplanet systems host technological civilizations that are radio loud in narrow-band emission between 1 and 2GHz at an equivalent isotropically radiated power (EIRP) of ~1.5x10^21^erg/s, approximately eight times the peak EIRP of the Arecibo Planetary Radar, and we limit the number of 1-2GHz narrow-band-radio-loud Kardashev type II civilizations in the Milky Way to be <10^-6^/M_{sun}_. Here we describe our observations, data reduction procedures and results.
- ID:
- ivo://CDS.VizieR/J/A+A/595/A77
- Title:
- GJ676A radial velocity curve
- Short Name:
- J/A+A/595/A77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The star GJ676A is an M0 dwarf hosting both gas-giant and super-Earth-type planets that were discovered with radial-velocity measurements. Using FORS2/VLT, we obtained position measurements of the star in the plane of the sky that tightly constrain its astrometric reflex motion caused by the super-Jupiter planet 'b' in a 1052-day orbit. This allows us to determine the mass of this planet to be M_b_= 6.7^+1.8^_-1.5_M_J_, which is ~40% higher than the minimum mass inferred from the radial-velocity orbit. Using new HARPS radial-velocity measurements, we improve upon the orbital parameters of the inner low-mass planets 'd' and 'e' and we determine the orbital period of the outer giant planet 'c' to be P_c_=7340-days under the assumption of a circular orbit. The preliminary minimum mass of planet 'c' is M_c_sini=6.8M_J_ with an upper limit of ~39M_J_ that we set using NACO/VLT high-contrast imaging. We also determine precise parallaxes and relative proper motions for both GJ676A and its wide M3 companion GJ676B. Although the system is probably quite mature, the masses and projected separations (~0.1-0.4") of planets 'b' and 'c' make them promising targets for direct imaging with future instruments in space and on extremely large telescopes. In particular, we estimate that GJ676A b and GJ676A ,c are promising targets for directly detecting their reflected light with the WFIRST space mission. Our study demonstrates the synergy of radial-velocity and astrometric surveys that is necessary to identify the best targets for such a mission.
- ID:
- ivo://CDS.VizieR/J/A+A/507/481
- Title:
- GJ 436b and XO-1b transits
- Short Name:
- J/A+A/507/481
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Currently the only technique sensitive to Earth mass planets around nearby stars (that are too close for microlensing) is the monitoring of the transit time variations of the transiting extrasolar planets. We search for additional planets in the systems of the hot Neptune GJ 436b, and the hot-Jupiter XO-1b, using high cadence observations in the J and KS bands. New high-precision transit timing measurements are reported: GJ 436b Tc=2454238.47898+/-0.00046HJD; XO-1b Tc(A)=2454218.83331+/-0.00114HJD, Tc(B)=2454222.77539+/-0.00036HJD, Tc(C)=2454222.77597+/-0.00039HJD, Tc(D)=2454226.71769+/-0.00034HJD, and they were used to derive new ephemeris. We also determined depths for these transits. No statistically significant timing deviations were detected. We demonstrate that the high cadence ground based near-infrared observations are successful in constraining the mean transit time to 30s, and are a viable alternative to space missions.
- ID:
- ivo://CDS.VizieR/J/A+A/608/A120
- Title:
- GJ 1214b optical and near-IR transit phot.
- Short Name:
- J/A+A/608/A120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The benchmark exoplanet GJ 1214b is one of the best studied transiting planets in the transition zone between rocky Earth-sized planets and gas or ice giants. This class of super-Earth or mini-Neptune planets is unknown in our solar system, yet is one of the most frequently detected classes of exoplanets. Understanding the transition from rocky to gaseous planets is a crucial step in the exploration of extrasolar planetary systems, in particular with regard to the potential habitability of this class of planets. GJ 1214b has already been studied in detail from various platforms at many different wavelengths. Our airborne observations with the Stratospheric Observatory for Infrared Astronomy (SOFIA) add information in the Paschen-{alpha}cont. 1.9um infrared wavelength band, which is not accessible by any other current ground- or space-based instrument due to telluric absorption or limited spectral coverage. We used FLIPO, the combination of the High-speed Imaging Photometer for Occultations (HIPO) and the First Light Infrared TEst CAMera (FLITECAM) and the Focal Plane Imager (FPI+) on SOFIA to comprehensively analyse the transmission signal of the possible water-world GJ 1214b through photometric observations during transit in three optical and one infrared channels. We present four simultaneous light curves and corresponding transit depths in three optical and one infrared channel, which we compare to previous observations and current synthetic atmospheric models of GJ 1214b. The final precision in transit depth is between 1.5 and 2.5 times the theoretical photon noise limit, not sensitive enough to constrain the theoretical models any better than previous observations. This is the first exoplanet observation with SOFIA that uses its full set of instruments available to exoplanet spectrophotometry. Therefore we use these results to evaluate SOFIAs potential in this field and suggest future improvements.
- ID:
- ivo://CDS.VizieR/J/A+A/556/A126
- Title:
- GJ667C Doppler and activity measurements
- Short Name:
- J/A+A/556/A126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Since low-mass stars have low luminosities, orbits at which liquid water can exist on Earth-sized planets are relatively close-in, which produces Doppler signals that are detectable using state-of-the-art Doppler spectroscopy. GJ 667C is already known to be orbited by two super-Earth candidates. We have recently applied developed data analysis methods to investigate whether the data supports the presence of additional companions. We obtain new Doppler measurements from HARPS extracted spectra and combined them with those obtained from the PFS and HIRES spectrographs. We used Bayesian and periodogram-based methods to re-assess the number of candidates and evaluated the confidence of each detection. Among other tests, we validated the planet candidates by analyzing correlations of each Doppler signal with measurements of several activity indices and investigated the possible quasi-periodic nature of signals.
- ID:
- ivo://CDS.VizieR/J/A+A/597/A108
- Title:
- GJ 536 HARPS and HARPS-N data
- Short Name:
- J/A+A/597/A108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of a super-Earth orbiting the star GJ 536 based on the analysis of the radial-velocity time series from the HARPS and HARPS-N spectrographs. GJ 536 b is a planet with a minimum mass Msini of 5.36+/-0.69M_{Earth}_ with an orbital period of 8.7076+/-0.0025 days at a distance of 0.066610(13) AU, and an orbit that is consistent with circular. The host star is the moderately quiet M1 V star GJ 536, located at 10 pc from the Sun. We find the presence of a second signal at 43 days that we relate to stellar rotation after analysing the time series of Ca II H&K and Halpha spectroscopic indicators and photometric data from the ASAS archive. We find no evidence linking the short period signal to any activity proxy. We also tentatively derived a stellar magnetic cycle of less than 3 years.
190. GJ 625 HARPS-N data
- ID:
- ivo://CDS.VizieR/J/A+A/605/A92
- Title:
- GJ 625 HARPS-N data
- Short Name:
- J/A+A/605/A92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of a super-Earth orbiting at the inner edge of the habitable zone of the star GJ 625 based on the analysis of the radial-velocity (RV) time series from the HARPS-N spectrograph, consisting in 151 HARPS-N measurements taken over 3.5yr. GJ 625 b is a planet with a minimum mass Msini of 2.82+/-0.51 M_Earth_ with an orbital period of 14.628+/-0.013 days at a distance of 0.078AU of its parent star. The host star is the quiet M2 V star GJ 625, located at 6.5pc from the Sun. We find the presence of a second radial velocity signal in the range 74-85 days that we relate to stellar rotation after analysing the time series of CaII H&K and H{alpha} spectroscopic indicators, the variations of the FWHM of the CCF and and the APT2 photometric light curves. We find no evidence linking the short period radial velocity signal to any activity proxy.