Partial Light Curves Research Articles

Photometric Geodesy of main-belt asteroids: I. Lightcurves of 26 large, rapid rotators

We present 5 years of lightcurve data on a sample of large, rapidly rotating asteroids selected for a program of “photometric geodysy.” A total of 257 complete or partial lightcurves were obtained for 26 asteroids, numbers 9, 15, 16, 22, 22, 29, 39, 41, 43, 45, 55, 65, 87, 88, 107, 125, 129, 130, 201, 216, 337, 349, 354, 511, 584, and 694. The observing protocol was designed to obtain precise absolute photometry at a wide variety of orbital longitudes and phase angles. The purpose of this data set is to allow determination (in future publications) of pole positions and shapes, and to constrain densities, strength, and other geophysical traits of these bodies.

UBV photometry of ten southern hemisphere active-chromosphere stars

High-precision UBV photometry of ten southern hemisphere active-chromosphere stars with strong Ca II H and K and/or H-alpha emission has been obtained. Eight of these stars showed variability during June 1985. Complete or partial light curves are presented for the stars, and these data, as well as mean V magnitudes and colors, are compared with the results of other investigators. In a number of cases, significant changes in photometric amplitude are found, which may serve to track the formation and evolution of active regions on these stars.

On the absolute magnitudes of RR Lyrae stars

view Abstract Citations (68) References (9) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On the Absolute Magnitudes of RR Lyrae Stars Barnes, T. G., III ; Hawley, S. L. Abstract The photometric data base used by Hawley and colleagues in 1986 to determine a mean absolute magnitude for RR Lyrae stars has been examined for systematic errors. Both the magnitudes published by Fitch et al. in 1966 and Clube and Dawe in 1980 for RR Lyrae stars are shown to differ systematically from intensity mean magnitudes. On the basis of new photometry, better relations are determined for inferring intensity mean magnitudes from partial light curves, using both the Fitch et al. and Clube and Dawe methods. In addition, it is shown that the Fitch et al. photometry requires magnitude-dependent corrections. After correcting the data base for the above effects, the statistical analysis was repeated to determine the mean absolute magnitude for 142 RRab stars with the result +0.68 + or - 0.14 mag. This is 0.08 mag brighter than the previous determination by Hawley et al. Publication: The Astrophysical Journal Pub Date: August 1986 DOI: 10.1086/184719 Bibcode: 1986ApJ...307L...9B Keywords: Astronomical Photometry; Stellar Magnitude; Variable Stars; Approximation; Astronomical Catalogs; Light Curve; Luminous Intensity; Astrophysics; STARS: RR LYRAE; STARS: VARIABLES full text sources ADS | data products SIMBAD (7)

The peculiar behaviour of the photometric variability of V508 Ophiuchi

RecentUBV observations of the eclipsing binary V508 Oph are presented. The obtained partial light curves show the typical behaviour of W UMA systems. The amplitudes of light variation are about 0 . 80, 0 . 86, and 0 . 94 inV, B, andU, respectively. This is not consistent with older photographic and photoelectricBV data which showed amplitudes of about 0 . 6 and 1 . 1 inV andB. Furthermore, the shapes of the light curves are not similar to the older ones. It is concluded that a strong change in the photometric behaviour of V508 Oph has probably occurred between 1981 and 1984.

NOTES ON TENSOUTHERN HEMISPHERE ECLIPSING BINARIES.

ABSTRACT Photoelectric B and V filter data averages have established the following minima: BF Cen at JD (hel.) 2444442.632, BB Cir 440.6014, SU For 891.6639, RR Nor 433.5976, AG Pav 889.5673, and KZ Pav 431.7550, 432.7040, and 441.7275. Revised periods have been derived for BF Cen, 3.693329 d, SU For, 2.434665 d, and KZ Pav, 0.9498768 d. A partial light curve with unusual properties is noted for XY Ant.

Light curves of SZ Piscium for 1977 and 1978

We present a relatively completeV-band light curve of SZ Psc for 1978 and a partial light curve for 1977. From the 1978 light curve we derive a new time of primary minimum, JD⊙2443823.674±0.001, and a Russell-model solution,i=75°.8±0°.1,r h =0.096±0.003,r c =0.351±0.001, andL h =0.253±0.002. The hotter component of this system is a F5-8 main-sequence star, the cooler component a K3-4 star well above the main sequence. The system is detached with the larger component filling only 82% of its Roche lobe. The distortion wave in this RS CVn-type binary seems not to migrate regularly as do those in many other such systems, but rather seems to change phase and amplitude more erratically. Between 1977 and 1978 its phase stayed practically constant while its amplitude decreased by a factor of three. We discuss the implications of this behavior for the spot model of RS CVn-type activity. We find that the traditional comparison star for SZ Psc, HD 219018, is very likely a constant star contrary to a recent suggestion that it is variable. Its brightness and colors,V=7.705, (B-V)=0.628, and (V-I) c =0.688, are those of a G2V star.