- ID:
- ivo://CDS.VizieR/J/A+A/635/A156
- Title:
- Total lunar eclipse January 2019 spectra
- Short Name:
- J/A+A/635/A156
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of the Earthshine o the Moon allow for the unique opportunity to measure the large-scale Earth atmosphere. Another opportunity is realized during a total lunar eclipse which, if seen from the Moon, is like a transit of the Earth in front of the Sun. We thus aim at transmission spectroscopy of an Earth transit by tracing the solar spectrum during the total lunar eclipse of January 21, 2019. Time series spectra of the Tycho crater were taken with the Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in its polarimetric mode in Stokes IQUV at a spectral resolution of 130000 (0.06{AA}). In particular, the spectra cover the red parts of the optical spectrum between 7419-9067{AA}. The spectrograph's exposure meter was used to obtain a light curve of the lunar eclipse. The brightness of the Moon dimmed by 10.75m during umbral eclipse. We found both branches of the O_2_ A-band almost completely saturated as well as a strong increase of H_2_O absorption during totality. A pseudo O_2_ emission feature remained at a wavelength of 7618{AA}, but it is actually only a residual from different P-branch and R-branch absorptions. It nevertheless traces the eclipse. The deep penumbral spectra show significant excess absorption from the NaI 5890{AA} doublet, the CaII infrared triplet around 8600{AA}, and the KI line at 7699{AA} in addition to several hyper-fine-structure lines of MnI and even from BaII. The detections of the latter two elements are likely due to an untypical solar center-to-limb eect rather than Earth's atmosphere. The absorption in CaII and KI remained visible throughout umbral eclipse. Our radial velocities trace a wavelength dependent Rossiter-McLaughlin eect of the Earth eclipsing the Sun as seen from the Tycho crater and thereby confirm earlier observations. A small continuum polarization of the O_2_ A-band of 0.12% during umbral eclipse was detected at 6.3. No line polarization of the O_2_ A-band, or any other spectral-line feature, is detected outside nor inside eclipse. It places an upper limit of 0.2% on the degree of line polarization during transmission through Earth's atmosphere and magnetosphere.
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- ID:
- ivo://CDS.VizieR/J/A+A/654/A108
- Title:
- Triple-frequency meteor radar reflection coeff.
- Short Name:
- J/A+A/654/A108
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Radar scattering from meteor trails depends on several poorly constrained quantities, such as electron line density, q, initial trail radius, r0, and ambipolar diffusion coefficient, D. The goal is to apply a numerical model of full wave backscatter to triple frequency echo measurements to validate theory and constrain estimates of electron radial distribution, initial trail radius, and the ambipolar diffusion coefficient. A selection of 50 transversely polarized and 50 parallel polarized echoes with complete trajectory information were identified from simultaneous tri-frequency echoes recorded by the Canadian Meteor Orbit Radar (CMOR). The amplitude-time profile of each echo was fit to our model using three different choices for the radial electron distribution assuming a Gaussian, parabolic exponential, and 1-by-r^2^ electron line density model. The observations were manually fit by varying, q, r0, and D per model until all three synthetic echo-amplitude profiles at each frequency matched observation. The Gaussian radial electron distribution was the most successful at fitting echo power profiles, followed by the 1/r^2^. We were unable to fit any echoes using a profile where electron density varied from the trail axis as an exponential-parabolic distribution. While fewer than 5% of all examined echoes had self-consistent fits, the estimates of r0 and D as a function of height obtained were broadly similar to earlier studies, though with considerable scatter. Most meteor echoes are found to not be described well by the idealized full wave scattering model.
- ID:
- ivo://CDS.VizieR/J/AJ/153/116
- Title:
- Trojan asteroids in the Kepler campaign 6 field
- Short Name:
- J/AJ/153/116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on a Kepler spacecraft survey during the K2 mission to characterize the rotational properties of 56 Trojan asteroids in the L4 cloud. More than one rotational period was observed for 51 of these targets, allowing for well constrained lightcurve rotation periods and amplitudes, five of which are found to be in conflict with previously published values. We find ~10% of objects have rotational periods longer than 100hr, an excess of slow rotators 10 times larger than suggested from the literature. Investigation of the rotational frequencies of our Kepler sample when combined with high-quality lightcurves in the literature reveals the distribution of rotational frequencies is non-Maxwellian even when consideration is given to size-dependent variations in rotational rate. From investigation of lightcurve shapes and amplitudes, we estimate the binary fraction within the Trojan population to be ~6%-36% depending on the methodology utilized to identify binary candidates.
- ID:
- ivo://CDS.VizieR/J/A+AS/138/247
- Title:
- Uranian satellites 1995-1998
- Short Name:
- J/A+AS/138/247
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Astrometric positions of the five largest Uranian satellites from 750 CCD frames taken at the oppositions of 1995 through 1998 are presented. The images were obtained over 35 nights. Observed positions are compared with the calculated positions from GUST86. The standard deviations are better than 0.05" for the four largest satellites and 0.08" for Miranda.
195. Uranian satellites
- ID:
- ivo://CDS.VizieR/J/A+AS/113/557
- Title:
- Uranian satellites
- Short Name:
- J/A+AS/113/557
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Astrometric positions of the five largest satellites are given for the oppositions of Uranus for the years 1989 to 1994. These positions were measured on 368 CCD frames obtained at the Cassegrain focus of a 1.6-m reflector. They are compared with the theoretically calculated positions from GUST86 (Laskar & Jacobson 1987). The observed minus calculated residuals referred to Oberon have standard deviations of the order of 0.05" for the three greatest Uranian satellites and 0.07" for Miranda. These residuals are comparable to the best available in the literature.
- ID:
- ivo://CDS.VizieR/J/other/OAP/29.155
- Title:
- Uranus & Neptune topocentric positions
- Short Name:
- J/other/OAP/29.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Catalogs of 145 astrometric positions of Uranus and 4 its moons U1-U4 and 62 positions of Neptune and Triton have been compiled with Tycho-2 as a reference frame from photographic observations obtained at the Main Astronomical Observatory, National Academy of Sciences of Ukraine, in 1963-1990. Astronegatives have been digitized with an Epson Expression 10000XL commercial scanner in 16-bit grayscale with a resolution of 1200 dpi. Reduction has been performed in the LINUX-MIDAS-ROMAFOT software supplemented with additional modules for the precise positional determination. The internal positional accuracy of the reduction is 0.04-0.25" for both coordinates and 0.21-0.65m for photographic magnitudes of the Tycho-2 catalog. Gallery of plate images used for catalogs: http://gua.db.ukr-vo.org/catalog_gallery.php?catn=neptun_1963_1990 http://gua.db.ukr-vo.org/catalog_gallery.php?catn=uran_1963_1990
- ID:
- ivo://CDS.VizieR/J/A+A/643/A125
- Title:
- (174567) Varda multi-chord stellar occultation
- Short Name:
- J/A+A/643/A125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present here results of the first-ever recorded stellar occultation by the large trans-Neptunian object (174567) Varda that was observed on September 10th, 2018. Varda belongs to the high-inclination dynamically excited population, and has a satellite, Ilmare, which is half the size of Varda.
- ID:
- ivo://CDS.VizieR/J/A+A/654/A48
- Title:
- V-band photometry of asteroids from ASAS-SN
- Short Name:
- J/A+A/654/A48
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We present V-band photometry of the 20000 brightest asteroids using data from the All-Sky Automated Survey for Supernovae (ASAS-SN) between 2012 and 2018. We were able to apply the convex inversion method to more than 5000 asteroids with more than 60 good measurements in order to derive their sidereal rotation periods, spin axis orientations, and shape models. We derive unique spin state and shape solutions for 760 asteroids, including 163 new determinations. This corresponds to a success rate of about 15%, which is significantly higher than the success rate previously achieved using photometry from surveys. We derive the first sidereal rotation periods for additional 69 asteroids. We find good agreement in spin periods and pole orientations for objects with prior solutions. We obtain a statistical sample of asteroid physical properties that is sufficient for the detection of several previously known trends, such as the underrepresentation of slow rotators in current databases, and the anisotropic distribution of spin orientations driven by the nongravitational forces. We also investigate the dependence of spin orientations on the rotation period. Since 2018, ASAS-SNhas been observing the sky with higher cadence and a deeper limiting magnitude, which will lead to many more new solutions in just a few years.
- ID:
- ivo://CDS.VizieR/J/A+A/606/A53
- Title:
- Venus mesosphere ALMA observations
- Short Name:
- J/A+A/606/A53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Water vapor and sulfur compounds are key species in the photochemistry of Venus mesosphere. These species, together with mesospheric temperatures, exhibit drastic temporal variations, both on short timescales (diurnal and day-to-day) as well on long timescales, far from being understood. We targeted CO, SO, H_2_O and SO_2_ transitions in the submillimeter range using the Atacama Large Millimeter Array (ALMA) to study their spatial and temporal variations. Four sets of observations were acquired on different dates in November 2011 during the first ALMA Early Science observation Cycle 0. Venus angular diameter was about 11" with an illumination factor of 92%, so that mostly the day side of the planet was mapped. Assuming a nominal CO abundance profile, we retrieved vertical temperature profiles over the entire disk as a function of latitude and local time. Temperature profiles were later used to retrieve SO, SO_2_, and H_2_O. We used H_2_O as a tracer for water assuming a D/H enrichment of 200 times the terrestrial value. We derived 3-D maps of mesospheric temperatures in the altitude range 70-105km. SO, SO_2_, and H_2_O are characterized by a negligible abundance below ~85km followed by an increase with altitude in the upper mesosphere. Disk-averaged SO abundances present a maximum mixing ratio of 15.0+/-3.1ppb on November 26 followed the next day by a minimum value of 9.9+/-1.2ppb. Due to a very low S/N, SO_2_ could only be derived from the disk-averaged spectrum on the first day of observation revealing an abundance of 16.5+/-4.6ppb. We found a SO_2_/SO ratio of 1.5+/-0.4. Global maps of SO reveal strong variations both with latitude and local time and from day to day with abundance ranging from <1 to 15ppb. H_2_O disk-averages retrievals reveal a steady decrease from November 14 to 27, with the abundance varying from 3.6+/-0.6ppm on the first day to 2.9+/-0.7ppm on the last day. H_2_O maps reveal a slightly higher abundance on the evening side compared to the morning side and a strong depletion between the first and the second day of observation.
- ID:
- ivo://CDS.VizieR/J/A+A/627/A82
- Title:
- Venus photometric flux and los velocities
- Short Name:
- J/A+A/627/A82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Measuring Venus' atmospheric circulation at different altitudes is important for understanding its complex dynamics, in particular the mechanisms driving the super-rotation. Observationally, Doppler imaging spectroscopy is in principle be the most reliable way to measure wind speeds of planetary atmospheres because it directly provides the projected speed of atmospheric particles. However, high-resolution imaging-spectroscopy is challenging, especially in the visible domain, and most of the knowledge about atmospheric dynamics has been obtained with cloud-tracking technique. The objective of the present work is to measure the global properties of Venus' atmospheric dynamics at the altitude of the uppermost clouds, which is probed by reflected solar lines in the visible domain. Our results are based on high-resolution spectroscopic observations with the long slit spectrometer of the solar telescope THEMIS. We present the first instantaneous "radial-velocity snapshot" of any planet of the solar system in the visible domain, i.e., a complete RV map of the planet obtained by stacking data on less than 10% of its rotation period. From this, we measure the properties of the zonal and meridional winds, which we unambiguously detect. We identify a wind circulation pattern that significantly differs from previous knowledge about Venus. The zonal wind displays a "hot spot" structure, featuring about 200m/s at sunrise and 70m/s at noon in the equatorial region. Regarding meridional winds, we detect an equator-to-pole meridional flow peaking at 45m/s at mid latitudes, i.e., which is about twice as large as what was reported so far.
