The absolute motion of the peculiar cluster NGC 6791

被引：41

作者：

Bedin, L. R.

Piotto, G.

Carraro, G.

King, I. R.

Anderson, J.

机构：

[1] Univ Padua, Dipartimento Astron, I-35122 Padua, Italy

[2] Univ Washington, Dept Astron, Seattle, WA 98195 USA

[3] Rice Univ, Dept Phys & Astron, Houston, TX 77251 USA

[4] European So Observ, D-85748 Garching, Germany

来源：

ASTRONOMY & ASTROPHYSICS | 2006年 / 460卷 / 02期

关键词：

astrometry; open clusters and associations : individual : NGC 6791; Galaxy : kinematics and dynamics;

D O I：

10.1051/0004-6361:20066085

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present improved values of the three components of the absolute space velocity of the open cluster NGC 6791. One HST ACS/WFC field with two-epoch observations provides astrometric measurements of objects in a field containing the cluster center. Identification of 60 background galaxies with sharp nuclei allows us to determine an absolute reference point, and measure the absolute proper motion of the cluster. We find (mu(alpha) cos delta, mu(delta))(J2000.0) = (-0.57 +/- 0.13, -2.45 +/- 0.12) mas yr(-1), and adopt V-rad = -47.1 +/- 0.7 km s(-1) from the average of the published values. Assuming a Galactic potential, we calculate the Galactic orbit of the cluster for various assumed distances, and briefly discuss the implications on the nature and the origin of this peculiar cluster.

引用

页码：L27 / L30

页数：4

共 15 条

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