* Astronomy

Members Login
Post Info TOPIC: Arcturus


L

Posts: 131433
Date:
Alpha Boötis
Permalink  
 


Arcturus (Alpha Boötis, HD 124897) is a red giant star located 36.7 light-years away in the constellation of Boötes

Picture 835 
Date: 15.05.17 


__________________


L

Posts: 131433
Date:
RE: Arcturus
Permalink  
 


Picture 342 
Date: 20.04.15 


__________________


L

Posts: 131433
Date:
Permalink  
 

Picture 008Picture 007
Date 23.03.15 


__________________


L

Posts: 131433
Date:
Permalink  
 

Picture 005Picture 011
 Arcturus labelled image. 


__________________


L

Posts: 131433
Date:
Permalink  
 

Arcturus culminates at midnight on 27 April

Read more



__________________


L

Posts: 131433
Date:
Permalink  
 

Title: The limb-darkened Arcturus; Imaging with the IOTA/IONIC interferometer
Authors: S. Lacour, S. Meimon, E. Thiebaut, G. Perrin, T. Verhoelst, E. Pedretti, P. A. Schuller, L. Mugnier, J. Monnier, J.P. Berger, X. Haubois, A. Poncelet, G. Le Besnerais, K. Eriksson, R. Millan-Gabet, M. Lacasse, W. Traub

This paper is an H band interferometric examination of Arcturus, a star frequently used as a spatial and spectral calibrator. Using the IOTA 3 telescope interferometer, we performed spectro-interferometric observation (R~35) of Arcturus. Atmospheric models and prescriptions were fitted to the data to derive the brightness distribution of the photosphere. Image reconstruction was also obtained using two software algorithms: Wisard and Mira. An achromatic power law proved to be a good model of the brightness distribution, with a limb darkening compatible with the one derived from atmospheric model simulations using our Marcs model. A Rosseland diameter of 21.05±0.21 was derived, corresponding to an effective temperature of T_eff=4295±26 K. No companion was detected from the closure phases, with an upper limit on the brightness ratio of 8e-4 at 1AU. Dynamic range at such distance from the photosphere was established at 1.5e-4 (1sigma rms). An upper limit of 1.7e-3 was also derived for the level of brightness asymmetries present on the photosphere.

Read more (500kb, PDF)

__________________
Page 1 of 1  sorted by
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard