Title:
Thermal infrared stellar interferometry using single-mode guided optics: first results with the TISIS experiment on IOTA
Authors:
Mennesson, B.; Mariotti, J. M.; Coudé Du Foresto, V.; Perrin, G.; Ridgway, S.; Ruilier, C.; Traub, W. A.; Carleton, N. P.; Lacasse, M. G.; Mazé, G.
Affiliation:
AA( DESPA, Observatoire de Paris, F-92195 Meudon, France), AB( DESPA, Observatoire de Paris, F-92195 Meudon, France; ESO, D-85748 Garching, Germany), AC( DESPA, Observatoire de Paris, F-92195 Meudon, France), AD( DESPA, Observatoire de Paris, F-92195 Meudon, France), AE(National Optical Astronomy Observatories, Tucson, AZ 85726-6732, USA), AF( DESPA, Observatoire de Paris, F-92195 Meudon, France), AG(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA), AH(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA), AI(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA), AJ(Le Verre Fluoré, Campus Ker Lann, F-35170 Bruz, France)
Journal:
Astronomy and Astrophysics, v.346, p.181-189 (1999) (A&A Homepage)
Publication Date:
06/1999
Origin:
A&A
A&A Keywords:
INSTRUMENTATION: INTERFEROMETERS, STARS: FUNDAMENTAL PARAMETERS, STARS: INDIVIDUAL: ALPHA HER, STARS: INDIVIDUAL: ARCTURUS, INFRARED: STARS
Abstract Copyright:
(c) 1999: Astronomy & Astrophysics
Bibliographic Code:
1999A&A...346..181M

Abstract

We report the first long baseline interferometric observations obtained in the thermal infrared with a single-mode fiber coupler. Stellar fringes have been found on alpha Bootis (Arcturus) and alpha Herculis, with a 21 m baseline of the Infrared and Optical Telescope Array (IOTA), located at the Smithsonian's Fred Lawrence Whipple Observatory (Mt Hopkins, Arizona). Beams from the telescopes are coherently combined through an X shaped fluoride glass single-mode fiber coupler. Although this device was not originally optimized for operation in the L band (effective wavelength of 3.75 mu m), we find good interferometric properties in that wavelength domain, with a rather high and steady instrumental transfer function, and very low dispersive effects. Observations are still limited by the poor sensitivity of the detectors and not by the thermal background, which was minimized. Visibilities derived from the interferograms are consistent with the published limb darkened diameters of alpha Herculis. It is, to our knowledge, the first time interferometric observations of Arcturus and alpha Her are reported in the L band.