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- ID:
- ivo://CDS.VizieR/J/A+AS/134/87
- Title:
- Photographic observations of visual binaries
- Short Name:
- J/A+AS/134/87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The photographic observations of 72 visual double stars are presented. The observations were made in the years 1992-1997 with the 60-cm double refractor of the Bosscha Observatory at Lembang.
- ID:
- ivo://CDS.VizieR/I/128
- Title:
- Photographic Obs. Visual Double Stars
- Short Name:
- I/128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains the results of photographic observations of 248 double stars, obtained at the Bosscha Observatory at Lembang, Indonesia 1981-1983.
- 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/154/30
- Title:
- Photometric study of fourteen low-mass binaries
- Short Name:
- J/AJ/154/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New CCD photometric observations of fourteen short-period low-mass eclipsing binaries (LMBs) in the photometric filters I, R, and V were used for a light curve analysis. A discrepancy remains between observed radii and those derived from the theoretical modeling for LMBs, in general. Mass calibration of all observed LMBs was performed using only the photometric indices. The light curve modeling of these selected systems was completed, yielding the new derived masses and radii for both components. We compared these systems with the compilation of other known double-lined LMB systems with uncertainties of masses and radii less then 5%, which includes 66 components of binaries where both spectroscopy and photometry were combined together. All of our systems are circular short-period binaries, and for some of them, the photospheric spots were also used. A purely photometric study of the light curves without spectroscopy seems unable to achieve high enough precision and accuracy in the masses and radii to act as meaningful test of the M-R relation for low-mass stars.
- 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/131/2664
- Title:
- Photometry and radial velocities of EY Cep
- Short Name:
- J/AJ/131/2664
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 6907 differential photometric observations in the V filter, as well as 52 radial velocities from spectroscopic observations of the detached, eccentric 7.97day double-lined eclipsing binary star EY Cep.
- 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.
