- ID:
- ivo://CDS.VizieR/J/A+A/470/231
- Title:
- JHKsIL' images of IRAS 06468-0325
- Short Name:
- J/A+A/470/231
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our new near-infrared J and Ks-band images taken towards IRAS 06468-0325 revealed the presence of extended emission with very unusual and enigmatic morphology: that of a diamond-ring, that is, a ring or torus with a bright source overlaping the edge of it (not inside it). We report the discovery of this source, explore its nature, and propose possible interpretations of its morphological structure. We observed IRAS 06468-0325 obtaining optical and infrared images through IJHKs and L' filters, K-band low-resolution spectroscopy, together with millimetre line observations of CO(1-0), ^13^CO(2-1), C^18^O(2-1), and CS(2-1).
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/608/A71
- Title:
- J,H,K spectroscopy of HD 106906 b
- Short Name:
- J/A+A/608/A71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Directly imaged planets are ideal candidates for spectroscopic characterization of their atmospheres. The angular separations that are typically close to their host stars, however, reduce the achievable contrast and thus signal-to-noise ratios (S/N). We spectroscopically characterize the atmosphere of HD 106906 b, which is a young low-mass companion near the deuterium burning limit. The wide separation from its host star of 7.1" makes it an ideal candidate for high S/N and high-resolution spectroscopy. We aim to derive new constraints on the spectral type, effective temperature, and luminosity of HD 106906 b and also to provide a high S/N template spectrum for future characterization of extrasolar planets. We obtained 1.1-2.5um integral field spectroscopy with the VLT/SINFONI instrument with a spectral resolution of R~=2000-4000. New estimates of the parameters of HD 106906 b are derived by analyzing spectral features, comparing the extracted spectra to spectral catalogs of other low-mass objects, and fitting with theoretical isochrones.
- ID:
- ivo://CDS.VizieR/J/A+A/459/669
- Title:
- JHKs photometry around {alpha} Cen
- Short Name:
- J/A+A/459/669
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- alpha Centauri is our closest stellar neighbor, at a distance of only 1.3pc, and its two main components have spectral types comparable to the Sun. This is therefore a favorable target for an imaging search for extrasolar planets. Moreover, indications exist that the gravitational mass of alpha Cen B is higher than its modeled mass, the difference being consistent with a substellar companion of a few tens of Jupiter masses. We searched for faint comoving companions to alpha Cen B. As a secondary objective, we built a catalogue of the detected background sources. We used the NACO adaptive optics system of the VLT in the J, H, and Ks bands to search for companions to alpha Cen B. This instrument allowed us to achieve a very high sensitivity to point-like sources, with a limiting magnitude of m_Ks~18 at 7" from the star. We complemented this data set with archival coronagraphic images from the HST-ACS instrument to obtain an accurate astrometric calibration.
- ID:
- ivo://CDS.VizieR/J/MNRAS/440/1470
- Title:
- Ji light curves of WTS-2
- Short Name:
- J/MNRAS/440/1470
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of WTS-2 b, an unusually close-in 1.02-d hot Jupiter (M_P_=1.12M_J_, R_P_=1.30R_J_) orbiting a K2V star, which has a possible gravitationally bound M-dwarf companion at 0.6-arcsec separation contributing ~20% of the total flux in the observed J-band light curve. The planet is only 1.5 times the separation from its host star at which it would be destroyed by Roche lobe overflow, and has a predicted remaining lifetime of just ~40Myr, assuming a tidal dissipation quality factor of Q'_*_=10^6^. Q'_*_ is a key factor in determining how frictional processes within a host star affect the orbital evolution of its companion giant planets, but it is currently poorly constrained by observations. We calculate that the orbital decay of WTS-2 b would correspond to a shift in its transit arrival time of T_shift_~17s after 15yr assuming Q'_*_=10^6^. A shift less than this would place a direct observational constraint on the lower limit of Q'_*_ in this system. We also report a correction to the previously published expected T_shift_ for WASP-18 b, finding that T_shift_=356s after 10yr for Q'_*_10^6^, which is much larger than the estimated 28s quoted in WASP-18 b discovery paper. We attempted to constrain Q'_*_ via a study of the entire population of known transiting hot Jupiters, but our results were inconclusive, requiring a more detailed treatment of transit survey sensitivities at long periods. We conclude that the most informative and straightforward constraints on Q'_*_ will be obtained by direct observational measurements of the shift in transit arrival times in individual hot Jupiter systems. We show that this is achievable across the mass spectrum of exoplanet host stars within a decade, and will directly probe the effects of stellar interior structure on tidal dissipation.
- ID:
- ivo://CDS.VizieR/J/A+A/640/A48
- Title:
- K2-32 and K2-233 light and RV curves
- Short Name:
- J/A+A/640/A48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-precision planetary densities are key pieces of information necessary to derive robust atmospheric properties for extrasolar planets. Measuring precise masses is the most challenging part of this task, especially in multi-planetary systems. The ESO-K2 collaboration focuses on the follow-up of a selection of multi-planetary systems detected by the K2 mission using the HARPS instrument with this goal in mind. In this work, we measure the masses and densities of two multi-planetary systems: a four-planet near resonant chain system (K2-32) and a young (~400Myr old) planetary system consisting of three close-in small planets (K2-233). We obtained 199 new HARPS observations for K2-32 and 124 for K2-233 covering a long baseline of more than three years. We performed a joint analysis of the radial velocities and K2 photometry with PASTIS to precisely measure and constrained the properties of these planets, focusing on their masses and orbital properties. We find that K2-32 is a compact scaled-down version of the Solar System's architecture, with a small rocky inner planet (Me=2.1_-1.1_^+1.3^M_{earth}_, Pe~4.35-days) followed by an inflated Neptune-mass planet (Mb=15.0_-1.7_^+1.8^M_{earth}_, Pb~8.99-days) and two external sub-Neptunes (Mc=8.1+/-2.4M_{earth}_, Pc~20.66-days; Md=6.7+/-2.5M_{earth}_, Pd~31.72-days). K2-32 becomes one of the few multi-planetary systems with four or more planets known where all have measured masses and radii. Additionally, we constrain the masses of the three planets in the K2-233 system through marginal detection of their induced radial velocity variations. For the two inner Earth-size planets we constrain their masses at a 95% confidence level to be smaller than Mb<11.3M_{earth}_ (Pb~2.47-days), Mc<12.8M_{earth}_ (Pc~7.06-days). The outer planet is a sub-Neptune size planet with an inferred mass of Md=8.3_-4.7_^+5.2^M_{earth}_ (Md<21.1M_{earth}_, Pd~24.36-days). Our observations of these two planetary systems confirm for the first time the rocky nature of two planets orbiting a young star, with relatively short orbital periods (<7-days). They provide key information for planet formation and evolution models of telluric planets. Additionally, the Neptune-like derived masses of the three planets, K2-32 b, c, d, puts them in a relatively unexplored regime of incident flux and planet mass, which is key for transmission spectroscopy studies in the near future.
- ID:
- ivo://CDS.VizieR/J/ApJ/636/1020
- Title:
- kappa Peg astrometry and radial velocities
- Short Name:
- J/ApJ/636/1020
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- {kappa} Pegasi is a well-known, nearby triple star system. It consists of a "wide" pair with semimajor axis =235mas, one component of which is a single-line spectroscopic binary (semimajor axis =2.5mas). Using high-precision differential astrometry and radial velocity observations, the masses for all three components are determined and the relative inclination between the wide and narrow pairs' orbits is found to be 43.8{deg}+/-3.0{deg}, just over the threshold for the three-body Kozai resonance. The system distance is determined to be 34.60+/-0.21pc and is consistent with trigonometric parallax measurements.
- ID:
- ivo://CDS.VizieR/J/AJ/159/2
- Title:
- K2-19b and c transit times and radial velocities
- Short Name:
- J/AJ/159/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- K2-19b and c were among the first planets discovered by NASA's K2 mission and together stand in stark contrast with the physical and orbital properties of the solar system planets. The planets are between the size of Uranus and Saturn at 7.0+/-0.2 R_{Earth}_ and 4.1+/-0.2 R_{Earth}_, respectively, and reside a mere 0.1% outside the nominal 3:2 mean-motion resonance. They represent a different outcome of the planet formation process than the solar system, as well as the vast majority of known exoplanets. We measured the physical and orbital properties of these planets using photometry from K2, Spitzer, and ground-based telescopes, along with radial velocities from Keck/HIRES. Through a joint photodynamical model, we found that the planets have moderate eccentricities of e~0.20 and well-aligned apsides {Delta}{omega}~0{deg}. The planets occupy a strictly nonresonant configuration: the resonant angles circulate rather than librate. This defies the predictions of standard formation pathways that invoke convergent or divergent migration, both of which predict {Delta}{omega}~180{deg} and eccentricities of a few percent or less. We measured masses of M_p,b_=32.4+/-1.7 M_{Earth}_ and M_p,c_=10.8+/-0.6 M_{Earth}_. Our measurements, with 5% fractional uncertainties, are among the most precise of any sub-Jovian exoplanet. Mass and size reflect a planet's core/envelope structure. Despite having a relatively massive core of M_core_~15 M_{Earth}_, K2-19b is envelope-rich, with an envelope mass fraction of roughly 50%. This planet poses a challenge to standard models of core-nucleated accretion, which predict that cores >~10 M_{Earth}_ will quickly accrete gas and trigger runaway accretion when the envelope mass exceeds that of the core.
- ID:
- ivo://CDS.VizieR/J/A+A/594/A50
- Title:
- K2-30 b and K2-34 b K2 light curves
- Short Name:
- J/A+A/594/A50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of the two hot Jupiters K2-30 b and K2-34 b. The two planets were detected during campaigns 4 and 5 of the extension of the Kepler mission, K2; they transit their main-sequence stars with periods of ~4.099 and ~2.996 days. Subsequent ground-based radial velocity follow-up with SOPHIE, HARPS-N, and CAFE established the planetary nature of the transiting objects. We analyzed the transit signal, radial velocity, and spectral energy distributions of the two systems to characterize their properties. Both planets (K2-30 b and K2-34 b) are bloated hot Jupiters (1.20R_Jup_ and 1.22R_Jup_) around relatively bright (V=13.5 and V=11.5) slow rotating main-sequence (G8 and F9) stars. Thus, these systems are good candidates for detecting the Rossiter-MacLaughlin effect in order to measure their obliquity and for atmospheric studies.
- ID:
- ivo://CDS.VizieR/J/A+A/601/A128
- Title:
- K2-19b and K2-19c radial velocity curves
- Short Name:
- J/A+A/601/A128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present radial velocity follow-up observations of K2-19,a compact planetary system hosting three planets, of which the two larger ones, K2-19b and K2-19c, are close to the 3:2 mean motion resonance. An analysis considering only the radial velocity measurements detects K2-19b, the larger and more massive planet in the system, with a mass of 54.8+/-7.5M_{earth}_ provides a marginal detection of K2-19c, with a mass of Mc,=5.9^+7.6^_-4.3_M_{earth}_. We also used the TRADES code to simultaneously model both our RV measurements and the existing transit timing measurements. We derived a mass of 54.4+/-8.9M_{earth}_ for K2-19b and of 7.5^+3.0^_-1.4_M_{earth}_ for K2-19c. For K2-19b, these masses are consistent with a previous determination that was principally based on a photodynamical analysis of the K2-19 light curve. Differences remain mainly in the mass determination of the more lightweight planet, driven likely by the limited precision of the RV measurements and possibly some as yet unrecognized systematics.
- ID:
- ivo://CDS.VizieR/J/A+A/633/A110
- Title:
- K band spectrum of beta Pictoris b
- Short Name:
- J/A+A/633/A110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Beta Pictoris is arguably one of the most studied stellar systems outside of our own. Some 30 years of observations have revealed a highly-structured circumstellar disk, with rings, belts, and a giant planet: beta Pictoris b. However very little is known about how this system came into being. Our objective is to estimate the C/O ratio in the atmosphere of {beta} Pictoris b and obtain an estimate of the dynamical mass of the planet, as well as to refine its orbital parameters using high-precision astrometry. We used the GRAVITY instrument with the four 8.2m telescopes of the Very Large Telescope Interferometer to obtain K-band spectro-interferometric data on {beta} Pic b. We extracted a medium resolution (R=500) K-band spectrum of the planet and a high- precision astrometric position. We estimated the planetary C/O ratio using two different approaches (forward modeling and free retrieval) from two different codes (ExoREM and petitRADTRANS, respectively). Finally, we used a simplified model of two formation scenarios (gravitational collapse and core-accretion) to determine which can best explain the measured C/O ratio. Our new astrometry disfavors a circular orbit for beta Pic b (e=0.15^+0.05^_-0.04_). Combined with previous results and with Hipparcos/GAIA measurements, this astrometry points to a planet mass of M=12.7+/-2.2M_{Jup}_. This value is compatible with the mass derived with the free-retrieval code petitRADTRANS using spectral data only. The forward modeling and free-retrieval approches yield very similar results regarding the atmosphere of beta Pic b. In particular, the C/O ratios derived with the two codes are identical (0.43+/-0.05 vs $0.43^+0.04^_-0.03_). We argue that if the stellar C/O in beta Pic is Solar, then this combination of a very high mass and a low C/O ratio for the planet suggests a formation through core-accretion, with strong planetesimal enrichment.
