- ID:
- ivo://CDS.VizieR/J/A+A/639/A11
- Title:
- Exocomets. A Spectroscopic Survey
- Short Name:
- J/A+A/639/A11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- While exoplanets are now routinely detected, the detection of small bodies in extrasolar systems remains challenging. Since the discovery of sporadic events, which are interpreted to be exocomets (falling evaporating bodies) around beta Pic in the early 1980s, Monly 20 stars have been reported to host exocomet-like events. We aim to expand the sample of known exocomet-host stars, as well as to monitor the hot-gas environment around stars with previously known exocometary activity. We have obtained high-resolution optical spectra of a heterogeneous sample of 117 main-sequence stars in the spectral type range from B8 to G8. The data were collected in 14 observing campaigns over the course of two years from both hemispheres. We analysed the CaII K&H and NaI D lines in order to search for non-photospheric absorptions that originated in the circumstellar environment and for variable events that could be caused by the outgassing of exocomet-like bodies. We detected non-photospheric absorptions towards 50% of the sample, thus attributing a circumstellar origin to half of the detections (i.e. 26% of the sample). Hot circumstellar gas was detected in the metallic lines inspected via narrow stable absorptions and/or variable blue- and red-shifted absorption events. Such variable events were found in 18 stars in the CaII and/or NaI lines; six of them are reported in the context of this work for the first time. In some cases, the variations we report in the CaII K line are similar to those observed in beta^L Pic. While we do not find a significant trend in the age or location of the stars, we do find that the probability of finding CS gas in stars with larger vsini is higher. We also find a weak trend with the presence of near-infrared excess and with anomalous (lambda Boo-like) abundances, but this would require confirmation by expanding the sample.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/583/A59
- Title:
- Gaia-FUN-SSO network. Apophis campaign
- Short Name:
- J/A+A/583/A59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Astrometric observations performed by the Gaia Follow-Up Network for Solar System Objects (Gaia-FUN-SSO) play a key role in ensuring that moving objects first detected by ESA's Gaia mission remain recoverable after their discovery. An observation campaign on the potentially hazardous asteroid (99942) Apophis was conducted during the asteroid's latest period of visibility, from 12/21/2012 to 5/2/2013, to test the coordination and evaluate the overall performance of the Gaia-FUN-SSO . The 2732 high quality astrometric observations acquired during the Gaia-FUN-SSO campaign were reduced with the Platform for Reduction of Astronomical Images Automatically (PRAIA), using the USNO CCD Astrograph Catalogue 4 (UCAC4, Cat. I/322) as a reference. The astrometric reduction process and the precision of the newly obtained measurements are discussed. We compare the residuals of astrometric observations that we obtained using this reduction process to data sets that were individually reduced by observers and accepted by the Minor Planet Center.
- ID:
- ivo://CDS.VizieR/J/other/SoSyR/50.344
- Title:
- Galilean moons & Jupiter positions
- Short Name:
- J/other/SoSyR/50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observational results are presented for Jupiter and its Galilean moons from the Normal Astrograph at Pulkovo Observatory in 2013-2015. The following data are obtained: 154 positions of the Galilean satellites and 47 calculated positions of Jupiter in the system of the UCAC4 (ICRS, J2000.0) catalogue; the differential coordinates of the satellites relative to one another are determined. The mean errors of the satellites normal places in right ascension and declination over the entire observational period are, respectively: (eps)RA=0.0065" and (eps)DE=0.0068", and their standard deviations are (sigm)RA=0.0804" and (sigm)DE=0.0845". The equatorial coordinates are compared with planetary and satellite motion theories. The average (O-C) residuals in the two coordinates relative to the motion theories are 0.05" or less. The best agreement with the observations is achieved by a combination of the EPM2011m and V. Lainey-V.2.0|V1.1 motion theories; the average (O-C) residuals are 0.03" or less. The (O-C) residuals for the features of the positions of Io and Ganymede are comparable with measurement errors. Jupiter's positions calculated from the observations of the satellites and their theoretical jovicentric coordinates are in good agreement with the motion theories. The (O-C) residuals for Jupiter's coordinates are, on average, 0.027" and -0.025" in the two coordinates.
- ID:
- ivo://CDS.VizieR/J/other/SoSyR/52.312
- Title:
- Galilean moons positions
- Short Name:
- J/other/SoSyR/52
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results of the Galilean moons observationals taken with Normal Astrograph of the Pulkovo Observatory in 2016-2017 are presented. 761 positions of the Galilean moons of Jupiter in the system of the Gaia DR1 catalog (ICRF, J2000.0) and 854 differential coordinates of the satellites relative to each other were obtained. The mean errors in the satellites' normal places and the corresponding root-mean-square deviations are (eps)RA=0.0020", (eps)DE=0.0027", (sigm)RA=0.0546", and (sigm)DE=0.0757". The equatorial coordinates of the moons are compared to the motion theories of planets and satellites. On average, the (O-C) residuals in the both coordinates relative to the motion theories are less than 0.031". The best agreement with observations is achieved by a combination of the EPM2015 and V. Lainey-V.2.0|V1.1 motion theories, which yields the average (O-C) residuals of approximately 0.02". Peculiarities in the behavior of the (O-C) residuals and error values in Ganymede have been noticed.
- ID:
- ivo://CDS.VizieR/J/other/SoSyR/49.383
- Title:
- Galilean satellites & Jupiter positions
- Short Name:
- J/other/SoSyR/49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- For observational period of 2009-2011 we have obtained 140 positions of Galilean satellites and 42 calculated positions of Jupiter in the system of UCAC4 catalogue (ICRS, J2000.0). Accuracy estimation gives error of mean position as 0.02-0.04". The resulting equatorial coordinates satellites were compared with the eight contemporary theories of the motion of planets and satellites. On average, the (O-C) residuals in both coordinates do not exceed 0.08" relative to all theories of motion. Comparison of the calculated equatorial coordinates of Jupiter (were obtained from observations of galilean satellites) with the INPOP10 theory of planetary motion has shown satisfactory results. The average deviations were obtained respectively (O-C)RA=0.040" and (O-C)DE=-0.053". This work was supported by the Program 22 of the Presidium of RAS and RFBR grant (12-02-00675-a).
- ID:
- ivo://CDS.VizieR/J/AJ/160/277
- Title:
- gri-light curve of near-Earth asteroid 2020 CD3
- Short Name:
- J/AJ/160/277
- Date:
- 08 Dec 2021
- Publisher:
- CDS
- Description:
- We report on our detailed characterization of Earth's second known temporary natural satellite, or minimoon, asteroid 2020CD3. An artificial origin can be ruled out based on its area-to-mass ratio and broadband photometry, which suggest that it is a silicate asteroid belonging to the S or V complex in asteroid taxonomy. The discovery of 2020CD3 allows for the first time a comparison between known minimoons and theoretical models of their expected physical and dynamical properties. The estimated diameter of 1.2_-0.2_^+0.4^m and geocentric capture approximately a decade after the first known minimoon, 2006RH120, are in agreement with theoretical predictions. The capture duration of 2020CD3 of at least 2.7yr is unexpectedly long compared to the simulation average, but it is in agreement with simulated minimoons that have close lunar encounters, providing additional support for the orbital models. 2020CD3's atypical rotation period, significantly longer than theoretical predictions, suggests that our understanding of meter-scale asteroids needs revision. More discoveries and a detailed characterization of the population can be expected with the forthcoming Vera C. Rubin Observatory Legacy Survey of Space and Time.
- ID:
- ivo://archive.stsci.edu/hut
- Title:
- Hopkins Ultraviolet Telescope
- Short Name:
- HUT
- Date:
- 22 Jul 2020 21:30:05
- Publisher:
- Space Telescope Science Institute Archive
- Description:
- The Hopkins Ultraviolet Telescope (HUT) was a shuttle-borne instrument used to obtain ultraviolet spectra in the far ultraviolet region of the spectrum. It was part of the ASTRO payload complement of three co-mounted instruments that flew in December 1990 and March 1995 as Space Shuttle missions. More than 650 spectra were obtained of 340 targets. In April, 2013, the HUT data was reprocessed to improve calibration, expand metadata, add new data products, and update file formats. The current cone service uses the metadata from these reprocessed files.
- ID:
- ivo://CDS.VizieR/J/AJ/157/139
- Title:
- Inner Oort cloud survey observations: 2015 TG387
- Short Name:
- J/AJ/157/139
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Inner Oort cloud objects (IOCs) are trans-Plutonian for their entire orbits. They are beyond the strong gravitational influences of the known planets, yet close enough to the Sun that outside forces are minimal. Here we report the discovery of the third known IOC after Sedna and 2012 VP113, called 2015 TG387. This object has a perihelion of 65+/-1 au and semimajor axis of 1170+/-70 au. The longitude of perihelion angle, {omega}, for 2015 TG387 is between that of Sedna and 2012 VP113 and thus similar to the main group of clustered extreme trans-Neptunian objects (ETNOs), which may be shepherded into similar orbital angles by an unknown massive distant planet called Planet X, or Planet Nine. The orbit of 2015 TG387 is stable over the age of the solar system from the known planets and Galactic tide. When including outside stellar encounters over 4 Gyr, 2015 TG387's orbit is usually stable, but its dynamical evolution depends on the stellar encounter scenarios used. Surprisingly, when including a massive Planet X beyond a few hundred au on an eccentric orbit that is antialigned in longitude of perihelion with most of the known ETNOs, we find that 2015 TG387 is typically stable for Planet X orbits that render the other ETNOs stable as well. Notably, 2015 TG387's argument of perihelion is constrained, and its longitude of perihelion librates about 180{deg} from Planet X's longitude of perihelion, keeping 2015 TG387 antialigned with Planet X over the age of the solar system.
- ID:
- ivo://CDS.VizieR/J/A+A/633/A65
- Title:
- (704) Interamnia images
- Short Name:
- J/A+A/633/A65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With an estimated diameter in the 320 to 350km range, (704) Interamnia is the fifth largest main belt asteroid and one of the few bodies that fills the gap in size between the four largest bodies with D>400km (Ceres, Vesta, Pallas and Hygiea) and the numerous smaller bodies with diameter 200 km. However, despite its large size, little is known about the shape and spin state of Interamnia and, therefore, about its bulk composition and past collisional evolution. We aimed to test at what size and mass the shape of a small body departs from a nearly ellipsoidal equilibrium shape (as observed in the case of the four largest asteroids) to an irregular shape as routinely observed in the case of smaller (D<=200km) bodies. We observed Interamnia as part of our ESO VLT/SPHERE large program (ID: 199.C-0074) at thirteen different epochs. In addition, several new optical lightcurves were recorded. These data, along with stellar occultation data from the literature, were fed to the All-Data Asteroid Modeling (ADAM) algorithm to reconstruct the 3D-shape model of Interamnia and to determine its spin state. Interamnia's volume-equivalent diameter of 332+/-6km implies a bulk density of {rho}=1.98+/-0.68g/cm^3^, which suggests that Interamnia - like Ceres and Hygiea - contains a high fraction of water ice, consistent with the paucity of apparent craters. Our observations reveal a shape that can be well approximated by an ellipsoid, and that is compatible with a fluid hydrostatic equilibrium at the 2{sigma}level. The rather regular shape of Interamnia implies that the size and mass limit, under which the shapes of minor bodies with a high amount of water ice in the subsurface become irregular, has to be searched among smaller (D<=300km) less massive (m<=3x10^19^kg) bodies.
- ID:
- ivo://CDS.VizieR/J/AJ/123/2070
- Title:
- ISO deep asteroid search
- Short Name:
- J/AJ/123/2070
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A total of six deep exposures (using the astronomical observation template CAM01 with a 6" pixel field of view) through the ISOCAM LW10 filter (IRAS band 1, i.e., 12{mu}m) were obtained on a ~15' square field centered on the ecliptic plane. Point sources were extracted using the technique described in 1999 by Deert et al. Twoknown asteroids appear in these frames, and 20 sources moving with velocities appropriate for main-belt asteroids are present. Most of the asteroids detected have flux densities less than 1 mJy, that is, between 150 and 350 times fainter than any of the asteroids observed by IRAS. These data provide the first direct measurement of the 12{mu}m sky-plane density for asteroids on the ecliptic equator. The median zodiacal foreground, as measured by ISOCAM during this survey, is found to be 22.1+/-1.5mJy/pixel, i.e. 26.2+/-1.7MJy/sr. The results presented here imply that the actual number of kilometer-sized asteroids may be higher than several recent estimates based upon observations at visual wavelengths and are in reasonable agreement with the statistical asteroid model. Using results from the observations presented here, together with three other recent population estimates, we conclude that the cumulative number of main-belt asteroids with diameters greater than 1km is (1.2+/-0.5)x10^6^.
