- ID:
- ivo://CDS.VizieR/J/AJ/156/223
- Title:
- Observations of the main-belt comets 238P & 288P
- Short Name:
- J/AJ/156/223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report observations of the reactivations of the main-belt comets (MBCs) 238P/Read and 288P/(300163) 2006 VW_139_ that also track the evolution of each object's activity over several months in 2016 and 2017. We additionally identify and analyze archival SDSS data showing 288P to have been active in 2000, meaning that both 238P and 288P have now each been confirmed to be active near perihelion on three separate occasions. From data obtained of 288P from 2012-2015 when it appeared inactive, we find best-fit R-band H, G phase function parameters of H_R_=16.80+/-0.12 mag and G_R_=0.18+/-0.11, corresponding to effective component radii of r_c_=0.80+/-0.04 km, assuming a binary system with equally sized components. Fitting linear functions to ejected dust masses inferred for 238P and 288P soon after their observed reactivations in 2016, we find an initial average net dust production rate of M_d_=0.7+/-0.3 kg/s and a best-fit start date of 2016 March 11 (when the object was at a true anomaly of {nu}=-63{deg}) for 238P, and an initial average net dust production rate of M_d_=5.6+/-0.7 kg/s and a best-fit start date of 2016 August 5 (when the object was at {nu}=-27{deg}) for 288P. Applying similar analyses to archival data, we find similar start points for previous active episodes for both objects, suggesting that minimal mantle growth or ice recession occurred between the active episodes in question. Some changes in dust production rates between active episodes are detected, however. More detailed dust modeling is suggested to further clarify the process of activity evolution in MBCs.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/500/L45
- Title:
- Observations of transits of the TrES-2 exoplanet
- Short Name:
- J/A+A/500/L45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report a possible change in the orbit parameters of the TrES-2 exoplanet. With a period of 2.470621 days, the TrES-2 exoplanet exhibits almost "grazing" transits 110.4-minutes duration as measured in 2006 by Holman and collaborators (2007, Cat. <J/ApJ/664/1185>). We observed two transits of TrES-2 in 2008 using the 1.2m Oskar-Luhning telescope (OLT) of Hamburg observatory employing CCD photometry in an i-band and a near to R-band filter. A careful lightcurve analysis including a re-analys is of the 2006 observations shows that the current transit duration has shortened since 2006 by ~3.16-minutes. Although the new observations were taken in a different filter we argue that the observed change in transit duration time cannot be attributed to the treatment of limb darkening. If we assume the stellar and planetary radii to be constant, a change in orbit inclination is the most likely cause of this change in transit duration.
- ID:
- ivo://CDS.VizieR/J/ApJ/722/880
- Title:
- Observations of two transits of HD 80606b
- Short Name:
- J/ApJ/722/880
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ground-based optical observations of the 2009 September and 2010 January transits of HD 80606b. Based on three partial light curves of the 2009 September event, we derive a midtransit time of T_c_[HJD]=2455099.196+/-0.026, which is about 1{sigma} away from the previously predicted time. We observed the 2010 January event from nine different locations, with most phases of the transit being observed by at least three different teams. We determine a midtransit time of T_c_[HJD]=2455210.6502+/-0.0064, which is within 1.3{sigma} of the time derived from a Spitzer observation of the same event.
- ID:
- ivo://CDS.VizieR/J/AJ/101/1352
- Title:
- Observations of variable stars in M9
- Short Name:
- J/AJ/101/1352
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of RR Lyrae variables near the transition between fundamental and first-overtone mode in the Oosterhoff type II (Oo II) globular clusters M80, M9, and NGC 2298 have been analyzed in a search for double-mode pulsators (RRd stars). These three clusters were selected because they have metal abundances that are intermediate between those of the Oo II clusters and the Oo I clusters that are known to have RRd stars. Any RRd stars identified in these three clusters would be useful for verification of a mass-metallicity relation. The analysis was based on published observations for all three clusters, and in addition, 44 CCD frames of M9 and 32 photographs of NGC 2298, all obtained with the University of Toronto telescope at Las Campanas. No new RRd stars were discovered. It is noted that the only globular clusters known to have RRd stars are the most metal poor Oo I clusters and metal poor Oo II clusters. Published observations of the RRd stars in M15 have been analyzed in order to determine accurate periods and period ratios for stars whose periods were previously considered to be uncertain.
- ID:
- ivo://CDS.VizieR/J/PAZh/26/13
- Title:
- Observations of X-ray binary A0535+26/V725 Tau
- Short Name:
- J/PAZh/26/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- UBV photoelectric observations of A0535+26/V725 Tau are obtained at Crimean Station of SAI in 1980 and 1988-1998.
- ID:
- ivo://CDS.VizieR/J/AJ/159/267
- Title:
- Observations & radial velocity of HATS-71b
- Short Name:
- J/AJ/159/267
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of HATS-71b, a transiting gas giant planet on a P=3.7955day orbit around a G=15.35mag M3 dwarf star. HATS-71 is the coolest M dwarf star known to host a hot Jupiter. The loss of light during transits is 4.7%, more than in any other confirmed transiting planet system. The planet was identified as a candidate by the ground-based HATSouth transit survey. It was confirmed using ground-based photometry, spectroscopy, and imaging, as well as space-based photometry from the NASA Transiting Exoplanet Survey Satellite mission (TIC234523599). Combining all of these data, and utilizing Gaia DR2, we find that the planet has a radius of 1.024{+/-}0.018R_J_ and mass of 0.37{+/-}0.24M_J_ (95% confidence upper limit of <0.80M_J_), while the star has a mass of 0.4861{+/-}0.0060M_{sun}_ and a radius of 0.4783{+/-}0.0060R_{sun}_.
- ID:
- ivo://CDS.VizieR/J/ApJ/793/50
- Title:
- Observed light curve of (3200) Phaethon
- Short Name:
- J/ApJ/793/50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (3200) Phaethon exhibits both comet- and asteroid-like properties, suggesting it could be a rare transitional object such as a dormant comet or previously volatile-rich asteroid. This justifies detailed study of (3200) Phaethon's physical properties as a better understanding of asteroid-comet transition objects can provide insight into minor body evolution. We therefore acquired time series photometry of (3200) Phaethon over 15 nights from 1994 to 2013, primarily using the Tektronix 2048x2048 pixel CCD on the University of Hawaii 2.2 m telescope. We utilized light curve inversion to (1) refine (3200) Phaethon's rotational period to P=3.6032+/-0.0008 hr; (2) estimate a rotational pole orientation of {lambda}=+85{deg}+/-13{deg} and {beta}=-20{deg}+/-10{deg}; and (3) derive a shape model. We also used our extensive light curve data set to estimate the slope parameter of (3200) Phaethon's phase curve as G~0.06, consistent with C-type asteroids. We discuss how this highly oblique pole orientation with a negative ecliptic latitude supports previous evidence for (3200) Phaethon's origin in the inner main asteroid belt as well as the potential for deeply buried volatiles fueling impulsive yet rare cometary outbursts.
- ID:
- ivo://CDS.VizieR/J/ApJ/788/72
- Title:
- Observed sample of z~0.7 massive galaxies
- Short Name:
- J/ApJ/788/72
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Detailed studies of the stellar populations of intermediate-redshift galaxies can shed light onto the processes responsible for the growth of the massive galaxy population in the last 8 billion years. We here take a step toward this goal by means of deep, multiobject rest-frame optical spectroscopy, performed with the Inamori Magellan Areal Camera and Spectrograph on the Magellan telescope, of a sample of ~70 galaxies in the Extended Chandra Deep Field South survey with redshift 0.65<=z<=0.75, apparent R>22.7 mag_Vega_, and stellar mass >10^10^ M_{sun}_. We measure velocity dispersion and stellar absorption features for individual sources. We interpret them by means of a large Monte Carlo library of star formation histories, following the Bayesian approach adopted for previous low redshift studies, and derive constraints on the stellar mass, mean stellar age, and stellar metallicity of these galaxies. We characterize for the first time the relations between stellar age and stellar mass and between stellar metallicity and stellar mass at z~0.7 for the galaxy population as a whole and for quiescent and star-forming galaxies separately. These relations of increasing age and metallicity with galaxy mass for the galaxy population as a whole have a similar shape as the z~0.1 analog derived for Sloan Digital Sky Survey galaxies but are shifted by -0.28 dex in age and by -0.13 dex in metallicity, at odds with simple passive evolution. Considering z=0.7 quiescent galaxies alone, we find that no additional star formation and chemical enrichment are required for them to evolve into the present-day quiescent population. However, other observations require the quiescent population to grow from z=0.7 to the present day. This growth could be supplied by the quenching of a fraction of z=0.7 M_{sstarf}_>10^11^ M_{sun}_ star-forming galaxies with metallicities already comparable to those of quiescent galaxies, thus leading to the observed increase of the scatter in age without affecting the metallicity distribution. However, rapid quenching of the entire population of massive star-forming galaxies at z=0.7 would be inconsistent with the age- and metallicity-mass relations for the population as a whole and with the metallicity distribution of star-forming galaxies only, which are, on average, 0.12 dex less metal rich than their local counterparts. This indicates chemical enrichment until the present in at least a fraction of the z=0.7 star-forming galaxies in our sample.
- ID:
- ivo://CDS.VizieR/J/AcA/43/209
- Title:
- OB stars extinction based in IR photometry
- Short Name:
- J/AcA/43/209
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The paper presents an extensive survey of interstellar extinction curves derived from the near IR photometric measurements of early type stars belonging to our Galaxy. This survey is more extensive and deeper than any other one, based on spectral data. The IR magnitudes of about 500 O and B type stars with E(B-V)>=0.05 were selected from literature. The IR color excesses are determined with the aid of "artificial standards". The results indicate that the extinction law changes from place to place. The mean galactic extinction curve in the near IR is very similar in different directions and changes very little from the value R=3.10+/-0.05 obtained in this paper.
- ID:
- ivo://CDS.VizieR/J/A+A/538/A142
- Title:
- OB stars in NGC 6334 and NGC 6357
- Short Name:
- J/A+A/538/A142
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Star-forming complexes are large structures exhibiting massive star-formation at different stages of evolution, from dense cores to well-developed HII regions. They are very interesting for the study of the formation and evolution of stars. NGC 6334 and NGC 6357 are two active and relatively nearby star-forming complexes. From the extinction map and the sub-mm cold dust emission, and because they have similar velocities, these regions are most likely connected. However, located in the direction of the Galactic center their radial velocity is not representative of their distance. An alternative is then to determine the distance of NGC 6334 and NGC 6357 from their stellar content. Our aim is to perform a census of O-B3 ionising stars in NGC 6334 and NGC 6357, to determine the extinction coefficient, and the distance of both regions. A census of O-B3 stars is an essential basis for estimating the statistical lifetime of the earliest massive star-forming phases.
