Zobrazeno 1 - 10
of 11
pro vyhledávání: '"Ana M. Larson"'
Autor:
Ana M. Larson
Publikováno v:
Canadian Historical Review. 100:497-498
Publikováno v:
International Astronomical Union Colloquium. 170:228-232
Low-amplitude, radial-velocity variations of bright late-type stars were monitored at the 1.2-m telescope of the Dominion Astrophysical Observatory (DAO) with the hydrogen fluoride (HF) absorption-cell technique. Many of the stars appear to be semi-r
Publikováno v:
International Astronomical Union Colloquium. 170:193-203
Nearly a decade ago, “yellow giants” were introduced as a new class of low-amplitude radial-velocity variable stars. In this report we discuss new results for 12 spectral type K and early-M giants based on long-term monitoring using both the hydr
Publikováno v:
International Astronomical Union Colloquium. 170:297-307
Binary systems can be analyzed like clusters but with additional constraints from the orbit. The theories of stellar interiors and atmospheres are used to analyze the color-magnitude diagram and spectra to test the consistency of theory and observati
Publikováno v:
Publications of the Astronomical Society of the Pacific. 110:98-104
The observed luminosity function (LF) of M30 shows an excess in the number of red giants relative to the number of turnoff stars as compared with the predictions of canonical models. This well-known problem is reexamined in the light of new stellar e
Autor:
Ana M. Larson, Alan Irwin
Publikováno v:
Astronomy and Astrophysics Supplement Series. 117:189-195
When analyzing any wavelength region, stellar spectroscopists must deal with the multitude of weak lines which depress the true continuum and thus form the pseudocontinuum. Calculating the eect of these lines, known collectively as the \line haze," u
Autor:
Gordon A. H. Walker, Derek C. Richardson, Shoufeng Yang, Andrew Walker, Ana M. Larson, Alan Irwin
Publikováno v:
Icarus. 116:359-375
We have carefully monitored the radial velocities of 21 bright, solar-type stars for 12 years, None has shown any reflex motion due to a substellar companion to an upper limit of between 1 and 3 Jupiter masses (X sin i) for orbital periods less than
Autor:
Byeong-Cheol Lee, Eike W. Guenther, William D. Cochran, Mathias Zechmeister, Kyungmin Kim, A. P. Hatzes, I. Han, Michael Endl, David Mkrtichian, Ana M. Larson, Shoufeng Yang, L. Girardi, Phillip J. MacQueen, Gordon A. H. Walker, M. Döllinger, A. E. Simon, M. Hartmann
Publikováno v:
Astronomy & Astrophysics. 580:A31
We investigate the nature of the long-period radial velocity variations in Alpha Tau first reported over 20 years ago. We analyzed precise stellar radial velocity measurements for Alpha Tau spanning over 30 years. An examination of the Halpha and Ca
Autor:
David A. Bohlender, Ana M. Larson, Alan Irwin, Gordon A. H. Walker, Cherie Goodenough, Shoufeng Yang, Andrew Walker
Publikováno v:
Publications of the Astronomical Society of the Pacific. 105:332
The stellar spectra obtained in our precise velocity program include the Ca II infrared triplet line at lambda-8662. Changes in the core flux of this line, quantified with our Delta-EW8662 index, reflect changes in stellar chromospheric activity. In
Autor:
G. A. H. Walker, D.A. Bohlender, Ana M. Larson, S. L. S. Yang, C. Goodenough, A. W. Irwin, A. R. Walker
Publikováno v:
International Astronomical Union Colloquium. 139:384-384
The hydrogen fluoride (HF) absorption cell technique has been used at the Canada-France-Hawaii Telescope for over a decade to monitor the radial velocity variability of nearby, solar-type stars in a search for substellar companions. As a complement t