The SIMBAD astronomical database

Wenger, M.; Ochsenbein, F.; Egret, D.; Dubois, P.; Bonnarel, F.; Borde, S.; Genova, F.; Jasniewicz, G.; Laloë, S.; Lesteven, Soizick; Monier, Richard

doi:10.1051/aas:2000332

Cited by 1,881 publications

(1,058 citation statements)

References 18 publications

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“…This can correspond to the case when a large-scale shock wave entrains in motion outer parts of the molecular clump while the dense central clump is less affected by the shock. SIMBAD database (Wenger et al 2000), VizieR catalogue access tool, operated at CDS, Strasbourg, France, NASA's Astrophysics Data System Bibliographic Services were extensively used for the article.…”

Section: Resultsmentioning

confidence: 99%

Gas kinematics in high-mass star-forming regions from the Perseus spiral arm

2017

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We present results of a survey of 14 star-forming regions from the Perseus spiral arm in CS (2-1) and 13 CO (1-0) lines with the Onsala Space Observatory 20 m telescope. Maps of 10 sources in both lines were obtained. For the remaining sources a map in just one line or a single-point spectrum were obtained. On the basis of newly obtained and published observational data we consider the relation between velocities of the "quasi-thermal" CS (2-1) line and 6.7 GHz methanol maser line in 24 high-mass star-forming regions in the Perseus arm. We show that, surprisingly, velocity ranges of 6.7 GHz methanol maser emission are predominantly red-shifted with respect to corresponding CS (2-1) line velocity ranges in the Perseus arm. We suggest that the predominance of the "red-shifted masers" in the Perseus arm could be related to the alignment of gas flows caused by the large-scale motions in the Galaxy. Large-scale galactic shock related to the spiral structure is supposed to affect the local kinematics of the star-forming regions. Part of the Perseus arm, between galactic longitudes from 85 • to 124 • , does not contain blue-shifted masers at all. Radial velocities of the sources are the greatest in this particular part of the arm, so the velocity difference is clearly pronounced. 13 CO (1-0) and CS (2-1) velocity maps of G183.35-0.58 show gas velocity difference between the center and the periphery of the molecular clump up to 1.2 km s −1 . Similar situation is likely to occur in G85.40-0.00. This can correspond to the case when the large-scale shock wave entrains the outer parts of a molecular clump in motion while the dense central clump is less affected by the shock.

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Section: Resultsmentioning

confidence: 99%

Gas kinematics in high-mass star-forming regions from the Perseus spiral arm

2017

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“…• HIP 85605 is also a double system and erroneous parallax for this star exists in Hipparcos, as pointed out by SIMBAD (Wenger et al 2000) database comment ("Parallax and proper motion are not compatible with CCDM J17296+2439A; the large proper motion and parallax of this star in Hipparcos (π=202mas, µ=362mas/yr) is most likely an artefact"). The similar opinion is expressed in .…”

Section: Stars Present In B-j But Omitted Herementioning

confidence: 97%

On the accuracy of close stellar approaches determination

Dybczyński

Berski

2015

Monthly Notices of the Royal Astronomical Society

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The aim of this paper is to demonstrate the accuracy of our knowledge of close stellar passage distances in the pre-GAIA era. We used the most precise astrometric and kinematic data available at the moment and prepared a list of 40 stars nominally passing (in the past or future) closer than 2 pc from the Sun. We used a full gravitational potential of the Galaxy to calculate the motion of the Sun and a star from their current positions to the proximity epoch. For this calculations we used a numerical integration in rectangular, Galactocentric coordinates. We showed that in many cases the numerical integration of the star motion gives significantly different results than popular rectilinear approximation. We found several new stellar candidates for close visitors in past or in future.We used a covariance matrices of the astrometric data for each star to estimate the accuracy of the obtained proximity distance and epoch. To this aim we used a Monte Carlo method, replaced each star with 10 000 of its clones and studied the distribution of their individual close passages near the Sun. We showed that for contemporary close neighbours the precision is quite good but for more distant stars it strongly depends on the quality of astrometric and kinematic data. Several examples are discussed in detail, among them the case of HIP 14473. For this star we obtained the nominal proximity distance as small as 0.22 pc 3.78 Myr ago. However there exist strong need for more precise astrometry of this star since the proximity point uncertainty is unacceptably large.

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“…Rather, the total flux was approximated by the product of the peak pixel value quoted in Figure 3 and the instrumental profile width (equal to the FWHM of the Gaussian model) of approximately 4.2 pixels. References: (1) SIMBAD (Wenger et al 2000), (2) Stone 1996 We then scaled the flux densities for each of the four spectral types in Stone (1996) to what they would be for an apparent V-band magnitude that is roughly representative of the V-band magnitude of the majority of the target stars within each spectral type, namely V=7 for F stars, V=8 for G stars, V=8 for K stars, and V=10 for M stars. (The stars from planet transit surveys are considerably fainter, V = 9 to 13, and those in the Kepler field are fainter still).…”

Section: Spectrophotometric Calibrationmentioning

confidence: 99%

A Search for Laser Emission with Megawatt Thresholds from 5600 FGKM Stars

Tellis¹,

Marcy²

2017

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We searched high resolution spectra of 5600 nearby stars for emission lines that are both inconsistent with a natural origin and unresolved spatially, as would be expected from extraterrestrial optical lasers.The spectra were obtained with the Keck 10-meter telescope, including light coming from within 0.5 arcsec of the star, corresponding typically to within a few to tens of au of the star, and covering nearly the entire visible wavelength range from 3640 to 7890 Å. We establish detection thresholds by injecting synthetic laser emission lines into our spectra and blindly analyzing them for detections. We compute flux density detection thresholds for all wavelengths and spectral types sampled. Our detection thresholds for the power of the lasers themselves range from 3 kW to 13 MW, independent of distance to the star but dependent on the competing "glare" of the spectral energy distribution of the star and on the wavelength of the laser light, launched from a benchmark, diffraction-limited 10-meter class telescope. We found no such laser emission coming from the planetary region around any of the 5600 stars. As they contain roughly 2000 lukewarm, Earth-size planets, we rule out models of the Milky Way in which over 0.1% of warm, Earth-size planets harbor technological civilizations that, intentionally or not, are beaming optical lasers toward us. A next generation spectroscopic laser search will be done by the Breakthrough Listen initiative, targeting more stars, especially stellar types overlooked here including spectral types O, B, A, early F, late M, and brown dwarfs, and astrophysical exotica.

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The SIMBAD astronomical database

Cited by 1,881 publications

References 18 publications

Gas kinematics in high-mass star-forming regions from the Perseus spiral arm

Gas kinematics in high-mass star-forming regions from the Perseus spiral arm

On the accuracy of close stellar approaches determination

A Search for Laser Emission with Megawatt Thresholds from 5600 FGKM Stars

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