- ID:
- ivo://CDS.VizieR/J/ApJS/236/18
- Title:
- OSSOS. VII. TNOs complete data release
- Short Name:
- J/ApJS/236/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Outer Solar System Origins Survey (OSSOS), a wide-field imaging program in 2013-2017 with the Canada-France-Hawaii Telescope, surveyed 155deg^2^ of sky to depths of m_r_=24.1-25.2. We present 838 outer solar system discoveries that are entirely free of ephemeris bias. This increases the inventory of trans-Neptunian objects (TNOs) with accurately known orbits by nearly 50%. Each minor planet has 20-60 Gaia/Pan-STARRS-calibrated astrometric measurements made over 2-5 oppositions, which allows accurate classification of their orbits within the trans-Neptunian dynamical populations. The populations orbiting in mean-motion resonance with Neptune are key to understanding Neptune's early migration. Our 313 resonant TNOs, including 132 plutinos, triple the available characterized sample and include new occupancy of distant resonances out to semimajor axis a ~130au. OSSOS doubles the known population of the nonresonant Kuiper Belt, providing 436 TNOs in this region, all with exceptionally high-quality orbits of a uncertainty {sigma}_a_<=0.1%; they show that the belt exists from a>~37au, with a lower perihelion bound of 35au. We confirm the presence of a concentrated low-inclination a~44 au "kernel" population and a dynamically cold population extending beyond the 2:1 resonance. We finely quantify the survey's observational biases. Our survey simulator provides a straightforward way to impose these biases on models of the trans-Neptunian orbit distributions, allowing statistical comparison to the discoveries. The OSSOS TNOs, unprecedented in their orbital precision for the size of the sample, are ideal for testing concepts of the history of giant planet migration in the solar system.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/244/19
- Title:
- OSSOS. XII. Subaru/HSC obs. of 65 TNOs
- Short Name:
- J/ApJS/244/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present variability measurements and partial light curves of trans-Neptunian objects (TNOs) from a two-night pilot study using Hyper Suprime-Cam (HSC) on the Subaru Telescope (Maunakea, Hawaii, USA). Subaru's large aperture (8m) and HSC's large field of view (1.77deg^2^) allow us to obtain measurements of multiple objects with a range of magnitudes in each telescope pointing. We observed 65 objects with m_r_=22.6-25.5mag in just six pointings, allowing 20-24 visits of each pointing over the two nights. Our sample, all discovered in the recent Outer Solar System Origins Survey (OSSOS), spans absolute magnitudes of H_r_=6.2-10.8mag and thus investigates smaller objects than previous light curve projects have typically studied. Our data supports the existence of a correlation between the light curve amplitude and absolute magnitude seen in other works but does not support a correlation between the amplitude and orbital inclination. Our sample includes a number of objects from different dynamical populations within the trans-Neptunian region, but we do not find any relationship between variability and the dynamical class. We were only able to estimate periods for 12 objects in the sample and found that a longer baseline of observations is required for a reliable period analysis. We find that 31 objects (just under half of our sample) have variability of {Delta}_mag_ greater than 0.4mag during all of the observations; in smaller 1.25hr, 1.85hr, and 2.45hr windows, the median {Delta}_mag_ is 0.13, 0.16, and 0.19mag, respectively. The fact that variability on this scale is common for small TNOs has important implications for discovery surveys (such as OSSOS or the Large Synoptic Survey Telescope) and color measurements.
- ID:
- ivo://CDS.VizieR/J/AJ/155/53
- Title:
- Outbursts and disk variability in Be stars
- Short Name:
- J/AJ/155/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In order to study the growth and evolution of circumstellar disks around classical Be stars, we analyze optical time-series photometry from the KELT survey with simultaneous infrared and visible spectroscopy from the Apache Point Observatory Galactic Evolution Experiment survey and Be Star Spectra database for a sample of 160 Galactic classical Be stars. The systems studied here show variability including transitions from a diskless to a disk-possessing state (and vice versa), and persistent disks that vary in strength, being replenished at either regularly or irregularly occurring intervals. We detect disk-building events (outbursts) in the light curves of 28% of our sample. Outbursts are more commonly observed in early- (57%), compared to mid- (27%) and late-type (8%) systems. A given system may show anywhere between 0 and 40 individual outbursts in its light curve, with amplitudes ranging up to ~0.5 mag and event durations between ~2 and 1000 days. We study how both the photometry and spectroscopy change together during active episodes of disk growth or dissipation, revealing details about the evolution of the circumstellar environment. We demonstrate that photometric activity is linked to changes in the inner disk, and show that, at least in some cases, the disk growth process is asymmetrical. Observational evidence of Be star disks both growing and clearing from the inside out is presented. The duration of disk buildup and dissipation phases are measured for 70 outbursts, and we find that the average outburst takes about twice as long to dissipate as it does to build up in optical photometry. Our analysis hints that dissipation of the inner disk occurs relatively slowly for late-type Be stars.
- ID:
- ivo://CDS.VizieR/J/A+A/401/271
- Title:
- Outbursts in the Be star HR 2501
- Short Name:
- J/A+A/401/271
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Several mostly unrelated periods or time scales characterize the variability of HR 2501. This star is a new lambda Eri star with a period of 0.79187d. This star also exhibits a mid- to long-term variability of characteristic time ~500d, most probably a consequence of the recurrent outbursts of matter from the rapidly rotating Be star towards its disk.
- ID:
- ivo://CDS.VizieR/J/MNRAS/275/591
- Title:
- Outer regions of Galactic Bulge
- Short Name:
- J/MNRAS/275/591
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Digitized UK Schmidt plate photometry, calibrated with CCD photometry, is obtained in 18 regions over the Bulge. Stars are selected for spectroscopic follow-up from with a carefully chosen colour-magnitude window, optimized for efficient detection of bulge K giants. Some 1500 stellar spectra are obtained with the AAT AUTOFIB facility. We derive a radial velocity and metallicity for each star, and quantify the uncertainties in these measurements. Luminosity classification is derived both by visual classification and by using an automated routine based on Principal Component Analysis. There are two basic results from this survey: the discovery of the Sagittarius dwarf galaxy described by Ibata, Gilmore and Irwin (1994Natur.370..194I), and a study of the Galactic Bulge by Ibata and Gilmore (1995MNRAS.275..605I) The catalogue contains coordinates, photometry, radial velocities, luminosity classification and chemical abundances for approximately 1500 stars in lines of sight towards the Galactic Bulge. A detailed description of the selection of these stars, the methods used to derive the data, and the reliability of the data, is presented in the paper.
- ID:
- ivo://CDS.VizieR/J/ApJ/809/91
- Title:
- Outflows in sodium excess objects
- Short Name:
- J/ApJ/809/91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Van Dokkum and Conroy (2010Natur.468..940V) revisited the unexpectedly strong NaI lines at 8200{AA} found in some giant elliptical galaxies and interpreted them as evidence for an unusually bottom-heavy initial mass function. Jeong et al. (2013, J/ApJS/208/7) later found a large population of galaxies showing equally extraordinary Na D doublet absorption lines at 5900{AA} (Na D excess objects: NEOs) and showed that their origins can be different for different types of galaxies. While a Na D excess seems to be related to the interstellar medium (ISM) in late-type galaxies, smooth-looking early-type NEOs show little or no dust extinction and hence no compelling signs of ISM contributions. To further test this finding, we measured the Doppler components in the Na D lines. We hypothesized that the ISM would have a better (albeit not definite) chance of showing a blueshift Doppler departure from the bulk of the stellar population due to outflow caused by either star formation or AGN activities. Many of the late-type NEOs clearly show blueshift in their Na D lines, which is consistent with the former interpretation that the Na D excess found in them is related to gas outflow caused by star formation. On the contrary, smooth-looking early-type NEOs do not show any notable Doppler components, which is also consistent with the interpretation of Jeong et al. that the Na D excess in early-type NEOs is likely not related to ISM activities but is purely stellar in origin.
- ID:
- ivo://CDS.VizieR/J/A+A/587/A51
- Title:
- Overlooked wide companions of nearby F stars
- Short Name:
- J/A+A/587/A51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We checked a sample of 545 F stars within 50pc for wide companions using existing near-infrared and optical sky surveys.
- ID:
- ivo://CDS.VizieR/I/225
- Title:
- Oxford 2 AC Zone Data Reduced to ACRS
- Short Name:
- I/225
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The U.S. Naval Observatory is in the process of making new reductions of the Astrographic Catalogue (AC) using a modern reference system, the ACRS, which represents the system of the FK5. The data from the Oxford 2 Zone, whose plates are centered between declinations +32 and +33 degrees (eq. 1900), have been analyzed for scale, rotation, tilt, coma, magnitude equation, radial distortion and distortions introduced by the use of reseaux in the Carte du Ciel program. The result is a positional catalog of over 117,000 stars on eq. J2000.0, epoch of observation. Additionally, all stars have been matched with the Tycho Input Catalog (revised); those numbers have been added for additional identification purposes.
- ID:
- ivo://CDS.VizieR/I/224
- Title:
- Oxford 1 AC Zone Data Reduced to ACRS
- Short Name:
- I/224
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The U.S. Naval Observatory is in the process of making new reductions of the Astrographic Catalogue (AC) using a modern reference system, the ACRS, which represents the system of the FK5. The data from the Oxford 1 Zone, whose plates are centered between declinations +25 and +31 degrees (eq. 1900), have been analyzed for scale, rotation, tilt, coma, magnitude equation, radial distortion and distortions introduced by the use of reseaux in the Carte du Ciel program. The result is a positional catalog of over 277,000 stars on eq. J2000.0, epoch of observation. Additionally, all stars have been matched with the Tycho Input Catalog (revised); those numbers have been added for additional identification purposes.
2640. Oxygen abundance in M83
- ID:
- ivo://CDS.VizieR/J/ApJ/695/580
- Title:
- Oxygen abundance in M83
- Short Name:
- J/ApJ/695/580
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained deep multiobject optical spectra of 49 HII regions in the outer disk of the spiral galaxy M83 (=NGC 5236) with the FORS2 spectrograph at the Very Large Telescope. The targets span the range in galactocentric distance between 0.64 and 2.64 times the R_25_ isophotal radius (5.4-22.3kpc), and 31 of them are located at R>R_25_, thus belonging to the extreme outer disk of the galaxy, populated by UV complexes revealed recently by the Galaxy Evolution Explorer satellite. In order to derive the nebular chemical abundances, we apply several diagnostics of the oxygen abundance, including R_23_, [NII]/[OII], and the [OIII]{lambda}4363 auroral line, which was detected in four HII regions.
