EXPORT: Near-IR observations of Vega-type and pre-main sequence stars^*

¹ Dpto. Física Teórica, C-XI, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
² Instituto de Astrofísica de Canarias, 38200 La Laguna, Tenerife, Spain
³ Instituto de Astrofísica de Andalucía, Apartado de Correos 3004, 18080 Granada, Spain
⁴ TNO/TPD-Space Instrumentation, Stieltjesweg 1, PO Box 155, 2600 AD Delft, The Netherlands
⁵ CNRS, Institute d'Astrophysique de Paris, 98bis Bd. Arago, 75014 Paris, France
⁶ NOAO/STIS, Goddard Space Flight Center, Code 681, NASA/GSFC, Greenbelt, MD 20771, USA
⁷ Physics & Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, Scotland, UK
⁸ Joint Astronomy Centre, 660 N. A'ohoku Place, Hilo, Hawaii 96720, USA
⁹ DLR Department of Planetary Exploration, Rutherfordstrasse 2, 12489 Berlin, Germany
¹⁰ L.A.E.F.F., VILSPA, Apartado de Correos 50727, 28080 Madrid, Spain
¹¹ Department of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
¹² Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, UK
¹³ Department of Physics, Center for Astrophysics and Space Sciences, University of California San Diego, Mail Code 0424, La Jolla, CA 92093-0424, USA
¹⁴ Observatoire de Paris, 92195 Meudon, France
¹⁵ SRON, Universiteitscomplex "Zernike", Landleven 12, PO Box 800, 9700 AV Groningen, The Netherlands

Corresponding author: C. Eiroa, carlos@xiada.ft.uam.es

Received: 18 August 2000
Accepted: 12 October 2000

Abstract

We present near-IR JHK photometric data of a sample of 58 main-sequence, mainly Vega-type, and pre-main sequence stars. The data were taken during four observing runs in the period May 1998 to January 1999 and form part of a coordinated effort with simultaneous optical spectroscopy and photo-polarimetry. The near-IR colors of the MS stars correspond in most cases to photospheric colors, although noticeable reddening is present towards a few objects, and these stars show no brightness variability within the observational errors. On the other hand, the PMS stars show near-IR excesses and variability consistent with previous data.