Z Chamaeleon

Return To Menu

VIEW Z CHA MOVIE

Photometric Monitoring of Z Chamaeleontis By Peter Starr BSc, 23 November 2009, Warrumbungle Observatory, Coonabarabran, NSW, Australia. I (Peter Starr) am an Amateur Astronomer and have authored this document, and conducted all the observations at my observatory near Coonabarabran NSW. Please note that I am not a professional astronomer but have a degree in chemistry and physics and undertaken post graduate astronomy and have some experience on professional telescopes. What I have written here is my work and interpretation unless otherwise referenced. This document has not been peer reviewed. Raw Data is available on request. Reduced data is available on the AAVSO website. Equipment: Telescope: Meade 14” LX200GPS, permanently mounted and polar aligned. Observatory: Sirius 3.2m. Camera: SBig CCD ST-8 Filters: Bessel U,B,V,R, Clear Calibration Frames: Darks Median combined at lights exposure and temperature. Sky flats median combined taken at dusk before lights for each filter. Reduction and photometric Analysis: Maxim DL version 5 Z Cha Z Cha is a cataclysmic variable star of the Su Uma type. It consists of a white dwarf, a red dwarf that has filled its roche lobe, an accretion disk about the white dwarf, a stream of gas from the red dwarf to the white dwarf at the inner lagrangian point forming a bright spot on the accretion disk. This star came of interest to me when I was randomly observing different CVs and noticed this one in particular with its constantly variable brightness. Before this it was unknown to me that this CV is an eclipsing CV which only a few are known to exist. The others being OY Car, HT Cas, and Oph. Z Cha is easily accessible located at RA 8hr 7’ 22.8” Dec -76o 32’ 1.0”. It is circumpolar from this location so can be observed all night at any time of year. Its position is also advantageous in that my observatory is manual and there is no need to rotate the dome during the night. Z cha was discovered by Mumford in 1968 and up until 1978 was the only known eclipsing CV. It was studied by Warner and helped understand the different components of CVs and their variable nature. Observations were made in 2007 and also throughout the first half of 2010. There are over 15 000 observations. Most of these observations were made when Z Cha was in quiescence but there are observations of 6 consecutive outbursts one of which was a superoutburst. Monitoring of this star will continue in order to observe more outbursts and super outbursts. Data can be found on the AAVSO website. Figure 1 shows an image of Z Cha and stars used a reference and check stars. These were selected based on charts and comparison stars from the AAVSO. Note that there is a faint star close to Z Cha. All photometric data of Z Cha done here includes the light from this star. It is assumed that this star is not variable. Observations by professional astronomers confirm this. I present an analysis of my data in a pdf below on data taken from March 2010 to June 2010. In due course this will be extended to the data captured in the previous 3 years

Download Z Cha PDF