Open AccessAngular diameter and effective temperature of a sample of 15 M giants at 2.2 μ m from lunar occultation observations
Author(s) -
Tej Anandmayee,
Chandrasekhar T.
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03672.x
Subject(s) - physics , occultation , angular diameter , angular resolution (graph drawing) , parallax , astrophysics , astronomy , late type star , effective temperature , stars , stellar atmosphere , mathematics , combinatorics
High angular resolution measurements of a sample of 15 M giants at 2.2 μm by the technique of lunar occultation are presented in this paper. We obtain angular diameters for 11 sources of which five are the first diameter measurements. For these resolved sources we have estimated the effective temperatures, which are consistent with previous calibrations. For the other four sources we put the first upper limits on their angular sizes to be 2 mas. Two sources, namely IRC+20090 and IRC+20067, yield appreciably low temperatures, which could point to their possible Mira nature. For sources with Hipparcos parallax measurements, we have calculated the linear radii.