Standard stars for comet photometry

Four-color and Hp Photometry of Stars

Charge-Coupled Device Photometry of Comet P/Halley

Comet P/Halley has been observed during its approach to perihelion at heliocentric distances R = I 1.0 AU and R = 8.2 AU. No extended coma is seen and limits can be placed on the fraction of the total light contributed by coma. The brightness of the comet varies on a short time scale. The variations may be due to transient activity or to rotation of the irregular nucleus. ,. 1984 Academic Pre',...

UBVJHK synthetic photometry of Galactic O stars

Aims. The development of powerful infrared observational technics enables the study of very extincted objects and young embedded star forming regions. This is especially interesting in the context of massive stars which form and spend a non negligible fraction of their life still enshrouded in their parental molecular cloud. Spectrophotometric calibrations are thus necessary to constrain the ph...

Long-term photometry of Be stars

Strömgren differential uvby photometry of λEri and HR2142 is analyzed. The data were taken during the time interval 1983–1994 in the framework of the Long-Term Photometry of Variables project at La Silla. λ Eri exhibited four photometric events (probably associatedwith line emission episodes) that last several months and which were characterized by a common pattern of change in all passbands (∼...

Broadband infrared photometry of comet Hale-Bopp with ISOPHOT

Comet Hale-Bopp was observed five times with ISOPHOT, the photometer on board ESA’s Infrared Space Observatory (ISO) between 4.6 and 2.8 AU. Each time, broadband photometry was performed using 4 different detectors, 5 apertures and 10 filters covering the range between 3.6 and 170 μm. Background observations were performed with identical instrument settings at the same positions on the sky seve...