Delta Vel: A new bright eclipsing binary

S. Otero reported the presence of eclipses of Delta Vel. Since 1997 he has recorded three probable eclipses at 2.2mag instead of its normal 1.95, estimating the candidates of its period to be 67.7d or 5.88854d, and then, confirmed the fourth eclipse in JD 2451714.9375 (vsnet-alert 5310). Paul D Fieseler informed to S. Otero that another fading was recorded by Galileo's star scanner in 1989 (JD 2447850.3 - 2447851.0). This fading doesn't fit with the ephemeris unless the period is decreasing at a fast rate. However this trend seems not to be present in the last eclipses. With the Galileo's data, S. Otero and C. Lloyd suggested that the dimmer point observed by Hipparcos satellite is not a real eclipse but an observation with large dispersion. Excluding the Hipparcos data, they found a new candidate of the period of 45.16 days, and furthermore both primary and secondary eclipses can be present (vsnet-campaign-deltavel 3, 4, 5).

S. Otero reported results by A. Jansen on October 31 - November 1 and 2, which detected an eclipse at the expected time from the period of 45 day (vsnet-campaign-deltavel 11). He also calculated a revised period of 45.15100 day and predict the subsequent eclipses on 2000 November 21 and 2000 December 17 (vsnet-campaign-deltavel 13, vsnet-campaign-deltavel 22, vsnet-campaign-deltavel 23). S. Otero reported no eclipse was observed on November 12 and not the other candidates but the 45.150 day period became now almost real (vsnet-campaign-deltavel 24, 26, 27).

S. Otero succeeded in confirming the secondary eclipse on November 21 as predicted. (vsnet-campaign-deltavel 29) and reported a comparison between predicted and observed magnitudes in [vsnet-campaign-deltavel 30] (see also, vsnet-campaign-deltavel 31, 32).

The eclipse observations by S. Otero on December 17 were seen in [vsnet-campaign-deltavel 33].

(S. Otero posted a light curve of eclipses to [vsnet-image 29] (vsnet-campaign-deltavel 34).