- ID:
- ivo://CDS.VizieR/J/ApJ/897/L10
- Title:
- Disturbance storm time index; 1903 Sun outburst
- Short Name:
- J/ApJ/897/L10
- Date:
- 15 Nov 2021 09:20:23
- Publisher:
- CDS
- Description:
- While the Sun is generally more eruptive during its maximum and declining phases, observational evidence shows certain cases of powerful solar eruptions during the quiet phase of solar activity. Occurring in the weak Solar Cycle 14 just after its minimum, the extreme space weather event in 1903 October-November is one of these cases. Here, we reconstruct the time series of geomagnetic activity based on contemporary observational records. With the mid-latitude magnetograms, the 1903 magnetic storm is thought to be caused by a fast coronal mass ejection (~1500km/s) and is regarded as a superstorm with an estimated minimum of the equivalent disturbance storm time index (Dst') of ~-531nT. The reconstructed time series has been compared with the equatorward extension of auroral oval (~44.1 in invariant latitude) and the time series of telegraphic disturbances. This case study shows that potential threats posed by extreme space weather events exist even during weak solar cycles or near their minima.
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- ID:
- ivo://CDS.VizieR/J/A+A/440/373
- Title:
- Earthbound interplanetary shocks
- Short Name:
- J/A+A/440/373
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This table contains space weather data based on 360 interplanetary shocks (forward and reverse) observed by ACE during the 80 month time period from January 1998 to August 2004. Data from ACE, WIND, LASCO and GOES are included, as well as Dst, Ap, SC information and SEC prediction times.
- ID:
- ivo://CDS.VizieR/VI/63
- Title:
- Earth Orbit, Precession and Insolation -20Myr to +10Myr
- Short Name:
- VI/63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- La93 is a program for computing the precession and obliquity of the Earth for various values of 1) the tidal effect of the Moon (CMAR) 2) the dynamical ellipticity of the Earth (FGAM) The nominal solution La90 corresponds to (CMAR = 0., FGAM = 1). The general solution will be called La93(CMAR,FGAM), thus La90 = La93(0.,1.) and La93(1.,1.) is obtained with the same tidal effect as in Quinn, Tremaine, Duncan (1991), although these solutions are not completely identical (see Laskar, Joutel, Boudin, 1993) The files and software of this package can be used in three different manners: 1) Contruction and Use of the nominal solution La93(0,1) The ASCII files ORBEL*.ASC contain the nominal orbital solution. The ASCII files PREC0*.ASC contain the nominal precession solution. The ASCII files CLIVAR0*.ASC contain the nominal climatic solution. The files PREC*.ASC and CLIVAR*.ASC can also be generated from the enclosed files (see section 2) For the computation of insolation quantities, the user will execute the 'prepinsol' step, and then 'insola'. 2) Construction of a parametrized La93(CMAR, FGAM) new solution The user reconstructs a complete La93(CMAR, FGAM) solution. The compilation of all required programs is obtained by running the command 'make' on a Unix machine. The preparation step 'prepa' needs to be done once, in order to prepare the necessary binary files. Then 'integ' will construct the new solutions for the given parameters (CMAR, FGAM). Alternatively, change in the Makefile the values of CMAR and FGAM before running the 'make clean' command (removes the files computed using the preceding values of CMAR and FGAM), and 'make La93'. 3) Changes in the model of precession, for example to take into account some feedback resulting from redistribution of the ice on the Earth resulting from climate changes. In this case, and in this case only, the user needs to edit the FORTRAN file integ.f More precisely, the subroutines which can be eventually modified are SUBROUTINE INIPRE(IPT) SUBROUTINE PRECES(t,AK,AH,AQ,AP,DK,DH,DQ,DP,AKI,DKI) The users may also want to adapt the driver INTEG to his specific needs
- ID:
- ivo://CDS.VizieR/J/A+A/635/A153
- Title:
- EMCCD observations of the 2018 Draconids
- Short Name:
- J/A+A/635/A153
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Several authors predicted an outburst of the Draconid meteor shower in 2018, but with an uncertain level of activity. Optical meteor observations were used to derive the population and mass indices, flux, and radiant positions of Draconid meteors. We performed 90 minutes of multi-station observations after the predicted peak of activity were performed using highly sensitive Electron Multiplying Charge Coupled Device (EMCCD) cameras. The data calibration is discussed in detail. A novel maximum likelihood estimation method of computing the population and mass index with robust error estimation was developed. We apply the method to observed Draconids and use the values to derive the flux. Meteor trajectories are computed and compared to predicted radiant positions from meteoroid ejection models. We find a mass index of 1.74+/-0.18 in the 30 min bin after the predicted peak, and 2.32+/-0.27 in the subsequent 60 min. The location and the dispersion of the radiant are a good match to modeled values, but there is an offset of 0.4{deg} in solar longitude.
- ID:
- ivo://CDS.VizieR/J/A+A/624/A36
- Title:
- EUV irradiances of the quiet Sun
- Short Name:
- J/A+A/624/A36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We benchmark new atomic data against a selection of irradiances obtained from medium-resolution quiet-Sun spectra in the extreme ultraviolet (EUV), from 60 to 1040{AA}. We used as a baseline the irradiances measured during solar minimum on 2008 April 14 by the prototype (PEVE) of the Solar Dynamics Observatory Extreme ultraviolet Variability Experiment (EVE). We took into account some inconsistencies in the PEVE data, using flight EVE data and irradiances we obtained from Solar and Heliospheric Observatory (SoHO) Coronal Diagnostics Spectrometer (CDS) data. We performed a differential emission measure and find overall excellent agreement (to within the accuracy of the observations, about 20%) between predicted and measured irradiances in most cases, although we point out several problems with the currently available ion charge-state distributions. We used the photospheric chemical abundances of Asplund et al. (2009ARA&A..47..481A). The new atomic data are nearly complete in this spectral range for medium-resolution irradiance spectra. Finally, we used observations of the active Sun in 1969 to show that the composition of the solar corona up to 1MK is nearly photospheric in this case as well. Variations of a factor of 2 are present for higher-temperature plasma, which is emitted within active regions. These results are in excellent agreement with our previous findings.
- 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.
- ID:
- ivo://CDS.VizieR/J/A+A/644/A23
- Title:
- Extended photometric survey of near-Earth objects
- Short Name:
- J/A+A/644/A23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The near-Earth objects (NEOs), whose proximity makes them the most accessible bodies in the Solar System, allow us to sample asteroids from tens of kilometers down to objects of a few meters in size. However, while the physical properties for the largest bodies are mostly known, we have very little physical information regarding the small NEOs. These objects today represent the overall majority among the ~2500 new discoveries each year, but they are usually only bright enough to be observable during their close approaches. Our aim was to extend our survey that started in 2015 on the NEO population, using ground-based observations to characterize the fainter (and typically smaller) NEOs observable each night. We performed BVRIz photometry of NEOs, making use of the DOLORES instrument at the Telescopio Nazionale Galileo (TNG, La Palma, Spain) and the Asiago Schmidt telescope (Italy), in order to derive visible color indexes and the taxonomic classification for each target in our sample. We taxonomically classified 51 new NEOs for the first time. Together with data obtained in our previous work and collected by other surveys available online, we analyzed an extended sample of 1081 individual NEOs. While the overall majority of them belong to the S-complex, our analysis of the taxonomic distribution found a larger contribution for dark bodies going toward larger H, suggesting that they could be more abundant among the fainter NEOs. Moreover, we find an interesting correlation between semi-major axis and diameter, which could be in part related to the Yarkovsky effect. Rapid characterization of the fainter NEO population shortly after their discovery will be crucial in the future, before those bodies become too faint to be observed, or lost forever.
- ID:
- ivo://CDS.VizieR/J/A+A/573/A21
- Title:
- Extinction of Titan haze at 3 micron
- Short Name:
- J/A+A/573/A21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The chemical nature of the Titan haze is poorly understood. The investigation carried out by the Cassini-Huygens suite of instruments is bringing new insights into this question. This work aims at deriving the vertical variation of the spectral structure of the 3.3-3.4um absorption feature of the Titan haze from Cassini VIMS solar occultation data recorded between 250 and 700km altitude.
- 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.
