- ID:
- ivo://CDS.VizieR/J/A+A/444/625
- Title:
- Photographic positions of the major planets
- Short Name:
- J/A+A/444/625
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a large database of photographic observations of Solar System bodies obtained at the Engelhadt Astronomical Observatory (EnAO). We give a brief description of the methods of observations and the accuracy of their reduction with the PPM and Tycho-2 catalogues. The photographic positions of the major planets, except Jupiter, are in the system of the Tycho-2 catalogue and their comparison with DE200 ephemeris coordinates are given.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/790/53
- Title:
- Photometric data of HD 209458b
- Short Name:
- J/ApJ/790/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The hot Jupiter HD 209458b is particularly amenable to detailed study as it is among the brightest transiting exoplanet systems currently known (V-mag = 7.65; K-mag = 6.308) and has a large planet-to-star contrast ratio. HD 209458b is predicted to be in synchronous rotation about its host star with a hot spot that is shifted eastward of the substellar point by superrotating equatorial winds. Here we present the first full-orbit observations of HD 209458b, in which its 4.5 {mu}m emission was recorded with Spitzer/IRAC. Our study revises the previous 4.5 {mu}m measurement of HD 209458b's secondary eclipse emission downward by ~35% to 0.1391%_-0.0069%_^+0.0072^%, changing our interpretation of the properties of its dayside atmosphere. We find that the hot spot on the planet's dayside is shifted eastward of the substellar point by 40.{deg}9+/-6.{deg}0, in agreement with circulation models predicting equatorial superrotation. HD 209458b's dayside (T_bright_= 1499+/-15 K) and nightside (T_bright_= 972+/-44 K) emission indicate a day-to-night brightness temperature contrast smaller than that observed for more highly irradiated exoplanets, suggesting that the day-to-night temperature contrast may be partially a function of the incident stellar radiation. The observed phase curve shape deviates modestly from global circulation model predictions potentially due to disequilibrium chemistry or deficiencies in the current hot CH_4_ line lists used in these models. Observations of the phase curve at additional wavelengths are needed in order to determine the possible presence and spatial extent of a dayside temperature inversion, as well as to improve our overall understanding of this planet's atmospheric circulation.
- ID:
- ivo://CDS.VizieR/J/MNRAS/444/711
- Title:
- Photometric distances of exoplanets
- Short Name:
- J/MNRAS/444/711
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Colour-magnitude diagrams form a traditional way of presenting luminous objects in the Universe and compare them to each other. Here, we estimate the photometric distance of 44 transiting exoplanetary systems. Parallaxes for seven systems confirm our methodology. Combining those measurements with fluxes obtained while planets were occulted by their host stars, we compose colour-magnitude diagrams in the near and mid-infrared. When possible, planets are plotted alongside very low mass stars and field brown dwarfs, who often share similar sizes and equilibrium temperatures. They offer a natural, empirical, comparison sample. We also include directly imaged exoplanets and the expected loci of pure blackbodies. Irradiated planets do not match blackbodies; their emission spectra are not featureless. For a given luminosity, hot Jupiters' daysides show a larger variety in colour than brown dwarfs do and display an increasing diversity in colour with decreasing intrinsic luminosity. The presence of an extra absorbent within the 4.5{mu}m band would reconcile outlying hot Jupiters with ultra-cool dwarfs' atmospheres. Measuring the emission of gas giants cooler than 1000K would disentangle whether planets' atmospheres behave more similarly to brown dwarfs' atmospheres than to blackbodies, whether they are akin to the young directly imaged planets, or if irradiated gas giants form their own sequence.
- ID:
- ivo://CDS.VizieR/J/ApJ/694/1559
- Title:
- Photometric follow-up observations of GJ 436b
- Short Name:
- J/ApJ/694/1559
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents multiband photometric follow-up observations of the Neptune-mass transiting planet GJ 436b, consisting of five new ground-based transit light curves obtained in 2007 May. Together with one already published light curve, we have at hand a total of six light curves, spanning 29 days. The analysis of the data yields an orbital period P=2.64386+/-0.00003 days, midtransit time T_c_[HJD]=2454235.8355+/-0.0001, planet mass M_p_=23.1+/-0.9M_{earth}_=0.073+/-0.003M_Jup_, planet radius R_p_=4.2+/-0.2R_{earth}_=0.37+/-0.01R_Jup_, and stellar radius R_s_=0.45+/-0.02R_{sun}_. Our typical precision for the midtransit timing for each transit is about 30s. We searched the data for a possible signature of a second planet in the system through transit timing variations (TTV) and variation of the impact parameter. The analysis could not rule out a small, of the order of a minute, TTV and a long-term modulation of the impact parameter, of the order of +0.2yr^-1^.
- ID:
- ivo://CDS.VizieR/J/AJ/152/75
- Title:
- Photometric survey of IC 2391, {eta} Cha, and USco
- Short Name:
- J/AJ/152/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The past two decades have seen a significant advancement in the detection, classification, and understanding of exoplanets and binaries. This is due, in large part, to the increase in use of small-aperture telescopes (<20cm) to survey large areas of the sky to milli-mag precision with rapid cadence. The vast majority of the planetary and binary systems studied to date consists of main-sequence or evolved objects, leading to a dearth of knowledge of properties at early times (<50Myr). Only a dozen binaries and one candidate transiting Hot Jupiter are known among pre-main-sequence objects, yet these are the systems that can provide the best constraints on stellar formation and planetary migration models. The deficiency in the number of well characterized systems is driven by the inherent and aperiodic variability found in pre-main-sequence objects, which can mask and mimic eclipse signals. Hence, a dramatic increase in the number of young systems with high-quality observations is highly desirable to guide further theoretical developments. We have recently completed a photometric survey of three nearby (<150pc) and young (<50Myr) moving groups with a small-aperture telescope. While our survey reached the requisite photometric precision, the temporal coverage was insufficient to detect Hot Jupiters. Nevertheless, we discovered 346 pre-main-sequence binary candidates, including 74 high-priority objects for further study.
- ID:
- ivo://CDS.VizieR/J/AJ/153/15
- Title:
- Photometry and spectroscopy of EPIC 201702477
- Short Name:
- J/AJ/153/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of EPIC 201702477b, a transiting brown dwarf in a long period (40.73691+/-0.00037day) and eccentric (e=0.2281+/-0.0026) orbit. This system was initially reported as a planetary candidate based on two transit events seen in K2 Campaign 1 photometry and later validated as an exoplanet candidate. We confirm the transit and refine the ephemeris with two subsequent ground-based detections of the transit using the Las Cumbres Observatory Global Telescope 1m telescope network. We rule out any transit timing variations above the level of ~30s. Using high precision radial velocity measurements from HARPS and SOPHIE we identify the transiting companion as a brown dwarf with a mass, radius, and bulk density of 66.9+/-1.7M_J_, 0.757+/-0.065R_J_, and 191+/-51g/cm^3^ respectively. EPIC 201702477b is the smallest radius brown dwarf yet discovered, with a mass just below the H-burning limit. It has the highest density of any planet, substellar mass object, or main-sequence star discovered so far. We find evidence in the set of known transiting brown dwarfs for two populations of objects-high mass brown dwarfs and low mass brown dwarfs. The higher-mass population have radii in very close agreement to theoretical models, and show a lower-mass limit around 60M_J_. This may be the signature of mass-dependent ejection of systems during the formation process.
- ID:
- ivo://CDS.VizieR/J/AJ/150/85
- Title:
- Photometry and spectroscopy of HAT-P-56
- Short Name:
- J/AJ/150/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of HAT-P-56b by the HATNet survey, an inflated hot Jupiter transiting a bright F-type star in Field 0 of NASA's K2 mission. We combine ground-based discovery and follow-up light curves with high precision photometry from K2, as well as ground-based radial velocities from the Tillinghast Reflector Echelle Spectrograph on the Fred Lawrence Whipple Observatory 1.5m telescope to determine the physical properties of this system. HAT-P-56b has a mass of 2.18M_J_, radius of 1.47R_J_, and transits its host star on a near-grazing orbit with a period of 2.7908day. The radius of HAT-P-56b is among the largest known for a planet with M_P_>2M_J_. The host star has a V-band magnitude of 10.9, mass of 1.30M_{sun}_, and radius of 1.43R_{sun}_. The periodogram of the K2 light curve suggests that the star is a {gamma} Dor variable. HAT-P-56b is an example of a ground-based discovery of a transiting planet, where space-based observations greatly improve the confidence in the confirmation of its planetary nature, and also improve the accuracy of the planetary parameters.
- ID:
- ivo://CDS.VizieR/J/AJ/150/197
- Title:
- Photometry and spectroscopy of HAT-P-57
- Short Name:
- J/AJ/150/197
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of HAT-P-57b, a P=2.4653 day transiting planet around a V=10.465+/-0.029mag, T_eff_=7500+/-250K main sequence A8V star with a projected rotation velocity of vsini=102.1+/-1.3km/s. We measure the radius of the planet to be R=1.413+/-0.054R_J_ and, based on RV observations, place a 95% confidence upper limit on its mass of M<1.85M_J_. Based on theoretical stellar evolution models, the host star has a mass and radius of 1.47+/-0.12M_{sun}_ and 1.500+/-0.050R_{sun}_, respectively. Spectroscopic observations made with Keck-I/HIRES during a partial transit event show the Doppler shadow of HAT-P-57b moving across the average spectral line profile of HAT-P-57, confirming the object as a planetary system. We use these observations, together with analytic formulae that we derive for the line profile distortions, to determine the projected angle between the spin axis of HAT-P-57 and the orbital axis of HAT-P-57b. The data permit two possible solutions, with -16.7{deg}<{lambda}<3.3{deg} or 27.6{deg}<{lambda}<57.4{deg} at 95% confidence, and with relative probabilities for the two modes of 26% and 74%, respectively. Adaptive optics imaging with MMT/Clio2 reveals an object located 2.7" from HAT-P-57 consisting of two point sources separated in turn from each other by 0.22". The H- and L'-band magnitudes of the companion stars are consistent with their being physically associated with HAT-P-57, in which case they are stars of mass 0.61+/-0.10M_{sun}_ and 0.53+/-0.08M_{sun}_. HAT-P-57 is the most rapidly rotating star, and only the fourth main sequence A star, known to host a transiting planet.
- ID:
- ivo://CDS.VizieR/J/AJ/149/149
- Title:
- Photometry and spectroscopy of HAT-P-54
- Short Name:
- J/AJ/149/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of HAT-P-54b, a planet transiting a late K dwarf star in field 0 of the NASA K2 mission. We combine ground-based photometric light curves with radial velocity measurements to determine the physical parameters of the system. HAT-P-54b has a mass of 0.760+/0.032M_J_, a radius of 0.944+/-0.028R_J_, and an orbital period of 3.7998days. The star has V=13.505+/0.060, a mass of 0.645+/-0.020M_{sun}_, a radius of 0.617+/-0.013R_{sun}_, an effective temperature of T_eff*_=4390+/-50, and a subsolar metallicity of [Fe/H]=-0.127+/-0.080. We also detect a periodic signal with P=15.6days and 5.6mmag amplitude in the light curve, which we interpret as due to the rotation of the star. HAT-P-54b has a radius that is smaller than 92% of the known transiting planets with masses greater than that of Saturn, while HAT-P-54 is one of the lowest-mass stars known to host a hot Jupiter. Follow-up high-precision photometric observations by the K2 mission promise to make this a well-studied planetary system.
- ID:
- ivo://CDS.VizieR/J/AJ/147/84
- Title:
- Photometry and spectroscopy of HAT-P-49
- Short Name:
- J/AJ/147/84
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of the transiting extrasolar planet HAT-P-49b. The planet transits the bright (V=10.3) slightly evolved F-star HD340099 with a mass of 1.54M_{Sun}_ and a radius of 1.83R_{Sun}_. HAT-P-49b is orbiting one of the 25 brightest stars to host a transiting planet which makes this a favorable candidate for detailed follow-up. This system is an especially strong target for Rossiter-McLaughlin follow-up due to the host star's fast rotation, 16km/s. The planetary companion has a period of 2.6915 days, mass of 1.73M_J_, and radius of 1.41R_J_. The planetary characteristics are consistent with that of a classical hot Jupiter but we note that this is the fourth most massive star to host a transiting planet with both M_p_ and R_p_ well determined.
