Starspots and exoplanets

✍ Scribed by A.P. Hatzes

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 93 KB
• Volume: 323
• Category: Article
• ISSN: 0004-6337
• DOI: 10.1002/1521-3994(200208)323:3/4<392::aid-asna392>3.0.co;2-m

✦ Synopsis

The discovery of exoplanets has resulted from a significant increase in the precision of stellar radial velocity measurements. In the past decade this precision has improved from several hundreds of m s ½ to a few m s ½ . In the near future astrometric measurements will make a similar increase in their precision by factors of several hundred. Although discovering exoplanets is driving the need for these precise measurements, these can also be used to study starspots on Sunlike stars. The largest sunspots can produce a radial velocity variation of several m s ½ and an astrometric signal of order tens of micro-arcseconds in a nearby solar-type star. The latter is well above the measurement precision of 4 micro-arcsecs provided by the Space Interferometry Mission (SIM). A combination of precise photometric, radial velocity, and astrometric measurements may enable us to derive spot distributions on slowly rotating late-type stars with solar-like levels of activity.