Measuring the Angular Size of the Sun
The balloon-borne Solar Disk Sextant (SDS) experiment has measured the angular size of the Sun on seven occasions spanning the years 1992 to 2011. The solar half-diameter -- observed in a 100-nm wide passband centered at 615 nm -- is found to vary over that period by up to 200 mas, while the typical estimated uncertainty of each measure is 20 mas. The diameter variation appears as if it might be cyclic, although it is not in phase with the solar activity cycle; thus, the measured diameter variation is not an observational artifact of surface activity. Our SDS group is planning future, annual flights over the next three years.
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03.15.2013 Priyamvada Natarajan, Professor of Astronomy, has been elected to an Honorary Professorship for life at the University of Delhi Congratulations! MORE INFO |
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02.25.2013 Yale astrophysicist elected head of American Astronomical Society Astrophysicist C. Megan Urry, Chair of Yale’s Physics Department and Director of the Center for Astronomy & Astrophysics, has been elected the next president of the world’s premier national astronomical society. MORE INFO |
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02.20.2013 Astronomers find smallest known planet — smaller than Mercury A team of scientists including two Yale University astronomers has discovered the smallest planet yet detected. MORE INFO |
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The Leitner Family Observatory and Planetarium is open every Tuesday night for a planetarium show. Weather permitting there will also be public viewing of planets, nebulae, star clusters and whatever happens to be interesting in the sky. Seats are available on a first come first serve basis. No reservations necessary.
Current updates are posted under the Newsblog and Calendar sections at leitnerobservatory.org
© 2013 Yale University. All Rights Reserved.
© 2013 Yale University. All Rights Reserved.