On the δ Scuti variability in the pre-main sequence Herbig Ae star HR 5999

¹ Laboratoire d'Astrophysique de l'OMP, CNRS UMR 5572, Observatoire Midi-Pyrénées, 14 avenue Édouard Belin, 31400 Toulouse, France
² Department of Astronomy, University of Cape Town, Rondebosch 7701, South Africa

Corresponding author: D. W. Kurtz, kurtz@ast.obs-mip.fr

Received: 19 October 2000
Accepted: 26 January 2001

Abstract

A reanalysis of photometric data for the bright, southern Herbig Ae star HR 5999 obtained by Praderie et al. ([CITE]) at ESO in 1985 shows δ Scuti pulsation with the same period, 4.812 d^-1, and semi-amplitude, 6 mmag, found by Kurtz & Marang ([CITE]) in data obtained from SAAO in 1994. HR 5999 is, therefore, a potential candidate to test Breger & Pamyatnykh's ([CITE]) predictions of evolutionary period changes 10 to 100 times faster in pre-main sequence δ Scuti stars than in post-main sequence stars. We argue that the low frequency, low amplitude CVn variability of HR 6000 with a period near 2 d, and its long-term variability are no hindrance to using it as a comparison star for study of the δ Scuti variability of HR 5999. With a separation of 44 arcsec between HR 5999 and HR 6000, and similar brightnesses for the two stars, we urge the use of small telescopes with CCD photometers to obtain the long-term data necessary for the study of period change. We point out that this can be done under less-than-ideal photometric conditions and urban lighting with CCD photometers on small telescopes which are widely available at small observatories, at universities and at the home observatories of serious amateur astronomers.