Főoldal     Alapinformációk     To Survive in the Universe    
Inhabited Sky
    News@Sky     Asztrofotók     Kollekció     Fórum     Blog New!     GYIK     Sajtó     Bejelentkezés  

HD 45720


Tartalom

Képek

Kép feltöltése

DSS Images   Other Images


Kapcsolódó cikkek

Mapping the contours of the Local bubble: preliminary results
We present preliminary results from a long-term program of mapping theneutral absorption characteristics of the local interstellar medium,taking advantage of Hipparcos stellar distances. Equivalent widths ofthe NaI D-line doublet at 5890 Å are presented for thelines-of-sight towards some 143 new target stars lying within 300 pc ofthe Sun. Using these data which were obtained at the Observatoire deHaute Provence, together with previously published NaI absorptionmeasurements towards a further 313 nearby targets, we present absorptionmaps of the distribution of neutral gas in the local interstellar mediumas viewed from 3 different galactic projections. In particular, thesemaps reveal the Local Bubble region as a low neutral densityinterstellar cavity in the galactic plane with radii between 65-250 pcthat is surrounded by a (dense) neutral gas boundary (or ``wall''). Wehave compared our iso-column contours with the contours derived bySnowden et al. (\cite{snowden98}) using ROSAT soft X-ray emission data.Consistency in the global dimensions derived for both sets of contoursis found for the case of a million degree hot LB plasma of emissivity0.0023 cm(-6) pc with an electron density of 0.005 cm(-2) . We havedetected only one relatively dense accumulation of cold, neutral gaswithin 60 pc of the Sun that surrounds the star delta Cyg, and note thatthe nearest molecular cloud complex of MBM 12 probably resides at thevery edge of the Local Bubble at a distance of ~ 90 pc. Our observationsmay also explain the very different physical properties of the columnsof interstellar gas in the line-of-sight to the two hot stars epsilonCMa and beta CMa as being due to their locations with respect to theBubble contours. Finally, in the meridian plane the LB cavity is foundto be elongated perpendicularly to the Gould's Belt plane, possiblybeing ``squeezed'' by the expanding shells of the Sco-Cen andPerseus-Taurus OB associations. Tables 1 and 2 are also available inelectronic form at the CDS (Strasbourg) via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html

Új cikk hozzáadása


Kapcsolódó hivatkozások

  • - (nincs kapcsolódó hivatkozás) -
Új link hozzáadása


Besorolás csoportokba:


Pozíciós és asztrometriai adatok

Csillagkép:Szekeres
Rektaszcenzió:06h31m03.10s
Deklináció:+39°45'16.6"
Vizuális fényesség:6.651
Távolság:163.666 parszek
RA sajátmozgás:1.8
Dec sajátmozgás:-28.8
B-T magnitude:6.661
V-T magnitude:6.652

Katalógusok és elnevezések:
Megfelelő nevek   (Edit)
HD 1989HD 45720
TYCHO-2 2000TYC 2932-2465-1
USNO-A2.0USNO-A2 1275-06357081
HIPHIP 31058

→ További katalógusok és elnevezések lekérése VizieR-ből