THE ACTIVITY AND VARIABILITY OF THE SUN AND SUN-LIKE STARS. II. CONTEMPORANEOUS PHOTOMETRY AND SPECTROSCOPY OF BRIGHT SOLAR ANALOGS

Journal Article · Wed Jul 15 04:00:00 EDT 2009 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/138/1/312; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21255686

Hall, Jeffrey C; Lockwood, G Wesley; Skiff, Brian A ^[1]; Henry, Gregory W ^[2]

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1. Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States)
2. Center of Excellence in Information Systems, 3500 John A. Merritt Blvd., Box 9501, Nashville, TN 37209 (United States)

We present 14 years of contemporaneous photometric and spectroscopic observations of 28 solar analog stars, taken with the Tennessee State University Automatic Photometric Telescopes at Fairborn Observatory and the Solar-Stellar Spectrograph at Lowell Observatory. These are the best observed and most nearly Sun-like of the targets in our magnitude-limited (V {<=} 7.5) sample. The correlations between luminosity and activity reveal the expected inverse activity-brightness correlations for active stars. Strong direct correlations between activity and brightness are not prevalent for the less active solar age stars, but are precision limited. The Sun does not appear to have unusually low photometric variability when compared with the most Sun-like inactive solar analogs. We present evidence that the activity index R'{sub HK} is not a good discriminant of Maunder Minimum candidate stars. On the basis of a star that appears to have transitioned from a low-variability state to a cycling state, we investigate the regime in which stars might switch from faculae-dominated to spot-dominated variations.

• OSTI ID: 21255686
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 1 Vol. 138; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
99 GENERAL AND MISCELLANEOUS
BRIGHTNESS
CORRELATIONS
FACULAE
INDEXES
LUMINOSITY
PHOTOMETRY
SPECTROSCOPY
SUN
TELESCOPES