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23242. USET Group form
- ID:
- ivo://ksb-orb.dc/uset_sunspot_group/q/usetsg
- Title:
- USET Group form
- Short Name:
- Group form
- Date:
- 14 Nov 2024 10:00:04
- Publisher:
- SIDC: Solar Influences Data analysis Center
- Description:
- USET Group form
23243. USET Groups
- ID:
- ivo://ksb-orb.dc/uset_sunspot_group/q/epn_core
- Title:
- USET Groups
- Short Name:
- uset_sunspot_gro
- Date:
- 14 Nov 2024 10:00:04
- Publisher:
- SIDC: Solar Influences Data analysis Center
- Description:
- *** USET Groups *** Values in the USET sunspot group catalog are derived from the solar drawings obtained by the Uccle Solar Equatorial Table (USET) facility that is located at the Royal Observatory of Belgium. The USET sunspot group catalog covers 82 years of observations in 2021, and is updated every day. A home-made software (DigiSun) written in Python is used to derive quantities such as location and areas from the sunspot drawings.
23244. U Sgr BV light curves
- ID:
- ivo://CDS.VizieR/J/PAZh/40/221
- Title:
- U Sgr BV light curves
- Short Name:
- J/PAZh/40/221
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- For the classical Cepheid U Sgr, we have constructed an O-C diagram spanning a time interval of 144 years. The O-C diagram has the shape of a parabola, which has made it possible to determine for the first time the quadratic light elements and to calculate the rate of evolutionary increase in the period, dP/dt=0.39(+/-0.10)s/yr, in agreement with the results of theoretical calculations for the third crossing of the instability strip. The available data reduced by the Eddington-Plakidis method reveal small random period fluctuations that do not distort the evolutionary trend in the O-C residuals.
23245. USGS_WMS
- ID:
- ivo://padc.obspm.planeto/usgs_wms/q/epn_core
- Title:
- USGS_WMS
- Short Name:
- usgs_wms.epn_cor
- Date:
- 16 Jul 2024 13:55:03
- Publisher:
- Paris Astronomical Data Centre - Constructor University
- Description:
- Catalogue of USGS Astrogeology WMS Map Layers
23246. USGS-WMS
- ID:
- ivo://jacobsuni/usgs_wms/q/epn_core
- Title:
- USGS-WMS
- Short Name:
- usgs_wms.epn_cor
- Date:
- 26 Apr 2022 19:06:25
- Publisher:
- JacobsUni EPN node
- Description:
- Catalog of USGS Astrogeology WMS Map Layers
- ID:
- ivo://CDS.VizieR/J/A+A/647/A167
- Title:
- Using H-bump to identify RSGs in NGC6822
- Short Name:
- J/A+A/647/A167
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a case study in which we used a novel method to identify red supergiant (RSG) candidates in NGC 6822 based on their 1.6um H-bump. We collected 32 bands of photometric data for NGC 6822 ranging from the optical to the mid-infrared (MIR), derived from Gaia, PS1, LGGS, VHS, UKIRT, IRSF, HAWK-I, Spitzer, and WISE. Using the theoretical spectra from MARCS, we demonstrate that there is a prominent difference around 1.6um (H-bump) between targets with high and low surface gravity (HSG and LSG). Taking advantage of this feature, we identify efficient color-color diagrams of rzH (r-z versus z-H) and rzK (r-z versus z-K) to separate HSG (mostly foreground dwarfs) and LSG targets (mainly background red giant stars, asymptotic giant branch stars, and RSGs) from crossmatching of optical and near-infrared (NIR) data. Moreover, synthetic photometry from ATLAS9 gives similar results. We further separated RSG candidates from the remaining LSG candidates as determined by the H-bump method by using semi-empirical criteria on NIR color-magnitude diagrams, where both the theoretic cuts and morphology of the RSG population are considered. This separation produced 323 RSG candidates. The simulation of foreground stars with Besancon models also indicates that our selection criteria are largely free from the contamination of Galactic giants. In addition to the H-bump method, we used the traditional BVR method (B-V versus V-R) as a comparison and/or supplement by applying a slightly aggressive cut to select as many RSG candidates as possible (358 targets). Furthermore, the Gaia astrometric solution was used to constrain the sample, where 181 and 193 targets were selected with the H-bump and BVR method, respectively. The percentages of selected targets in the two methods are similar at ~60%, indicating a comparable accuracy of the two methods. In total, there are 234 RSG candidates after combining targets from the two methods, and 140 (~60%) of them are in common. The final RSG candidates are in the expected locations on the mid-infrared color-magnitude diagram with [3.6]-[4.5]<~0 and J-[8.0]~1.0. The spatial distribution is also coincident with the far-ultraviolet-selected star formation regions, suggesting that the selection is reasonable and reliable. We indicate that our method can also be used to identify other LSG targets, such as red giants and asymptotic giant branch stars, and it can also be applied to most of the nearby galaxies by using recent large-scale ground-based surveys. Future ground- and space-based facilities may promote its application beyond the Local Group.
- ID:
- ivo://org.gavo.dc/tutreg/gavo_vocourse/rec
- Title:
- Using the Virtual Observatory
- Short Name:
- GAVO vo course
- Date:
- 03 Apr 2025 09:49:31
- Publisher:
- The GAVO DC team
- Description:
- This is a course on using the Virtual Observatory (VO), an international research data infrastructure in Astronomy and Astrophysics. Starting with a brief discussion of some general concepts, it introduces some of the major client programs like TOPCAT and Aladin, together with some simple discovery protocols. A first focus topic is the query language ADQL, which is treated within the equivalent of three lectures. The second major focus of the course is the premier Python interface to the VO, pyVO, which is used to also more deeply investigate the topics treated before. The course is complemented by a number of side tracks, brief discussions of more fundamental or more specialised VO topics. The course comes with many exercises, most of which also have solutions. We hope it is suitable for both self-study and as lecture notes in teacher-led situations. In the latter case, it is designed to work as a semester-long course with two hours of lectures and lab work each per week.
23249. US Naval Observatory B
- ID:
- ivo://sdss.jhu/openskynode/usnob
- Title:
- US Naval Observatory B
- Short Name:
- USNOB
- Date:
- 05 Dec 2018 20:07:20
- Publisher:
- US Naval Observatory
- Description:
- The USNO-B1.0 Catalogue presents positions, proper motions, magnitudes in various optical passbands, and star/galaxy estimators for 1,045,175,762 objects derived from 3,648,832,040 separate observations. The data were taken from scans of 7,435 Schmidt plates taken from various sky surveys during the last 50 years. The catalogue is expected to be complete down to V=21; the estimated accuracies are 0.2arcsec for the positions at J2000, 0.3mag in up to 5 colors, and 85% accuracy for distinguishing stars from non-stellar objects
- ID:
- ivo://CDS.VizieR/I/163
- Title:
- US Naval Observatory Pleiades Catalog
- Short Name:
- I/163
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog is a special subset of the Eichhorn et al. (1970) Pleiades catalog (see <I/90>) updated to B1950.0 positions and with proper motions added. It was prepared for the purpose of predicting occultations of Pleiades stars by the Moon, but is useful for general applications because it contains many faint stars not present in the current series of large astrometric catalogs.
