首页     To Survive in the Universe    
Services
    Why to Inhabit     Top Contributors     天文图片     收集     论坛     Blog New!     常见问题     登录  
→ Adopt this star  

HD 67642


目录

图像

上传图像

DSS Images   Other Images


相关文章

An Einstein Observatory SAO-based catalog of B-type stars
About 4000 X-ray images obtained with the Einstein Observatory are usedto measure the 0.16-4.0 keV emission from 1545 B-type SAO stars fallingin the about 10 percent of the sky surveyed with the IPC. Seventy-fourdetected X-ray sources with B-type stars are identified, and it isestimated that no more than 15 can be misidentified. Upper limits to theX-ray emission of the remaining stars are presented. In addition tosummarizing the X-ray measurements and giving other relevant opticaldata, the present extensive catalog discusses the reduction process andanalyzes selection effects associated with both SAO catalog completenessand IPC target selection procedures. It is concluded that X-rayemission, at the level of Lx not less than 10 exp 30 ergs/s, is quitecommon in B stars of early spectral types (B0-B3), regardless ofluminosity class, but that emission, at the same level, becomes lesscommon, or nonexistent, in later B-type stars.

The VELA star cloud. III - The B8 to A0 stars and interstellar reddening
The present discussion of intermediate band and H-beta observations of360 HD stars B8-A0 in Vela, and all of the CPD stars in a small adjacentregion, notes that the interstellar absorption in both cases can beunderstood as a combination of three absorbing clouds of 1 kpc-A(V) =1.5, 0.5, and 0.17. The major difference in the two environments is thepresence of numerous T Tauri stars in Taurus. Several clusters in theVela region are discussed.

The common origin of some open clusters
Eight open clusters have been observed with uvby-beta photometry and forseven of them the metal abundances have been determined. Six of thesehave similar metallicities. They are close in space and are also knownto have similar ages and radial velocities. These clusters are suspectedof having a common origin. Some studies are made of the reliability ofthe photometric system. A large gain in limiting magnitude can beachieved against an unimportant loss of accuracy if interference filtersare removed.

The VELA star cloud. I - NGC 2547, TR 10, the Gamma Velorum system, and bright stars
The first results of an intermediate-band, large-scale photometricsurvey of the Vela star cloud are discussed. Attention is given to theluminosity and reddening, as well as the apparent or proper motions ofall the CPD stars near NGC 2547, the brightest stars in Trumpler 10, arandom selection of stars in the region of Gamma Velorum, and the HRstars. The similarity of the Alpha Persei cluster with the clusters inthe Vela sheet is shown, and it is found that the Vela sheet, at leastover the region surveyed, is nearly perpendicular to the line of sight.The probability is demonstrated that a thin sheet of coeval (2.5 x 10 tothe 7th yr) stars, some 425 pc distant and with a similar metalabundance, lies in front of a dense dark cloud.

提交文章


相关链接

  • - 没有找到链接 -
提交链接


下列团体成员


观测天体数据

星座:船帆座
右阿森松:08h06m50.18s
赤纬:-47°33'37.8"
视星:7.998
距离:300.3 天文距离
右阿森松适当运动:-9.3
赤纬适当运动:2.9
B-T magnitude:7.966
V-T magnitude:7.996

目录:
适当名称
HD 1989HD 67642
TYCHO-2 2000TYC 8140-5948-1
USNO-A2.0USNO-A2 0375-04796777
HIPHIP 39699

→ 要求更多目录从vizier