Archive for January, 2012

AAVSO top visual observers

Posted January 28, 2012 By grigoris

I just stumbled upon an interesting article about Rod Stubbings, a visual observer who made more than 200,000th variable star observations! This, as Mike Simonsen says, places him in top five visual observers in the history of variable star astronomy. An interesting image of the persons and their corresponding number of observations (through the year […]

Zip multiple directories separately

Posted January 20, 2012 By grigoris

In order to zip simultaneously a number of directories, but keep them separate, the following command will just do the job (in bash): for i in *; do zip -r $ $i; done (caution: all directories inside which this command is executed will be zipped, so make a separate directory only to create the zip […]

PSF or DIA data from OGLE II?

Posted January 17, 2012 By grigoris

OGLE (Optical Gravitational Lensing Experiment) has a large database of photometry data available to the public. OGLE II data (second phase) are available with option to select the photometry method used, ie. PSF and DIA photometry. PSF, a modified DOPHOT photometry process, was used during the first phase of OGLE, while the DIA process (Difference […]

VStar conflicts with java used

Posted January 16, 2012 By grigoris

VStar is a multi-platform variable star visualisation and analysis tool, developed under the CitizenSky project and the AAVSO. Its use is straightforward if java is installed. But you should be carefull what java you are using… I tried to use VStar in two different machines running Ubuntu 10.10 64bit and Fedora 14 32bit and the […]

Watec’s illumination issue

Posted January 16, 2012 By grigoris

During one observing night in December 2011, I noticed a strange “illumination” in the field, as the image from MetRec shows.   What is obvious from the above image is that there is too much light coming from the bottom, which affects the regions of interest, the flat-field image and the sensitivity image. As a […]

Bash commands to combine files

Posted January 9, 2012 By grigoris

Suppose that you want to combine two (or more) files, containing for example a series of data. There are, actually, two ways to do it in bash: $ paste temp1 temp2 > temp which adds the contents of the two files horizontally, like columns, and $ cat temp1 temp2 > temp which adds the contents […]