目录
图像
上传图像
DSS Images Other Images
相关文章
Lacerta OB1 Revisited
This investigation utilizes precise uvby? photometry and therecently recalculated Hipparcos data to provide an improved homogeneousdistance scale for the apparent groups of young stars in Lacerta. Allexisting uvby? photometry for stars earlier than A0-type in a20°×20° field centered at l=100°, b=-15° iscollated and the individual stellar distances and color excesses areobtained. The association Lac OB1 is reliably identified as a verycompact young group of 12 bright stars at an average distance of520±20(s.e.) pc. The available radial velocity and proper motionmeasurements strongly support the impression that the group is real. Thestars in the northeast part of Lacerta seem not to represent a physicalgroup, but rather a layer of field stars spread between 140 and 400 pcand extending farther than that toward l˜104°. An estimate of678±50(s.e.) pc of the distance to the open cluster NGC 7243 isobtained based on the brightest cluster members. The calculateddistances are based on a well-tested procedure, and thus represent aclarification over the range of distance existing in the literature forthe bright stars in the Lacerta field. Although a better agreement isnow evident between the photometric distances and the recalculatedHipparcos parallaxes in comparison to the original Hipparcos data,discrepancies still exist for this particular field.
|
提交文章
相关链接
提交链接
下列团体成员
|
观测天体数据
目录:
|
