TRIGONOMETRIC PARALLAXES OF MASSIVE STAR-FORMING REGIONS. II. CEP A AND NGC 7538
- 1. INAF, Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze (Italy)
- 2. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
- 3. Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany)
- 4. Department of Astronomy, Nanjing University, Nanjing 210093 (China)
Description
We report trigonometric parallaxes for the sources NGC 7538 and Cep A, corresponding to distances of 2.65+0.12-0.11 and 0.70+0.04-0.04 kpc, respectively. The distance to NGC 7538 is considerably smaller than its kinematic distance and places it in the Perseus spiral arm. The distance to Cep A is also smaller than its kinematic distance and places it in the Localarm or spur. Combining the distance and proper motions with observed radial velocities gives the location and full space motion of the star-forming regions. We find significant deviations from circular galactic orbits for these sources: both sources show large peculiar motions (greater than 10 km s-1) counter to galactic rotation and NGC 7538 has a comparable peculiar motion toward the Galactic center.
Availability note (English)
Available from http://dx.doi.org/10.1088/0004-637X/693/1/406Additional details
Identifiers
Publishing Information
- Journal Title
- Astrophysical Journal
- Journal Volume
- 693
- Journal Issue
- 1
- Journal Page Range
- p. 406-412
- ISSN
- 0004-637X
- CODEN
- ASJOAB
INIS
- Country of Publication
- United States
- Country of Input or Organization
- International Atomic Energy Agency (IAEA)
- INIS RN
- 41029629
- Subject category
- S79: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY;
- Descriptors DEI
- DISTANCE; GALAXIES; MASERS; ORBITS; PROPER MOTION; RADIAL VELOCITY; ROTATION; STARS
- Descriptors DEC
- AMPLIFIERS; ELECTRONIC EQUIPMENT; EQUIPMENT; MICROWAVE AMPLIFIERS; MICROWAVE EQUIPMENT; MOTION; VELOCITY