Does anyone know what the 5 different magnitudes represent in the ASAS V data? they are all listed as the Same HJD. Are these 4 sequential exposures with the mean time at the HJD shown? Are they from the same camera or different ones. ASAS only has 4 cameras and I don't think they are all pointing at the same patch of sky at the same time. I haven't found a description of the data file (not the catalog) on the ASAS website. If someone knows where it is, pointing me toward it would be a help.
I am trying to understand which of the values I should use (they are all V band) or whether I should average them when making a light curve from the data.
Example from Data:
HJD
MAG_0
MAG_1
MAG_2
MAG_3
MAG_4
MER_0
MER_1
MER_2
MER_3
MER_4
GRADE
FRAME
FLAG
3886.979
14.015
14.046
14.038
13.982
13.745
0.041
0.027
0.019
0.018
0.019
D
392
0
3889.99
14.066
14.168
14.186
14.142
13.981
0.061
0.053
0.034
0.028
0.025
D
793
0
Brad Walter, WBY
Brad,
ASAS computes the magnitudes using different apertures, with the smallest (MAG_0) being two pixels wide, and the largest being six. The smallest aperture is appropriate for the faintest stars (V fainter than 12), while the largest is for the brightest stars.
There's a good summary of this on the following page, about half way down:
https://sites.google.com/site/aavsosequenceteam/asas-tutorial
Matthew
Thanks Matthew.
Just FYI, I've written an ASAS plugin for VStar and it's currently under test. I hope to make it available next week.
David
Anyone with insights into the current status of ASAS north and whether the data will become available?
/Gustav, HGUA
Gustav,
The only data from ASAS north of which I am aware is about a years worth of data circa 1999, If I recall correctly, for most of the Kepler field.
After that, I haven't seen data or updates on the ASAS website.
Brad Walter
In the last few weeks a team of scientist started to report some discoveries on ATEL made by the ASAS-SN project. It seems they use a pair of 14cm telescopes located at Hawaii and found some transient object on the northern sky. For me it seems they have lack of capacity, probably that is the reason why they report their discoveries mostly several deays or even weeks after the discovery images were taken.
I'm afraid comprehansive new ASAS-North or ASAS-SN photometry databases will not likely be published within the near future.
It seems ASAS-North observed SN2011dh two years ago: http://www.astro.princeton.edu/~jprieto/ASAS/SN2011dh/
ASAS-SN page on Prieto's website: http://www.astro.princeton.edu/~jprieto/ASAS/
Abstract from the American Astronomical Society, AAS Meeting #220, #432.03 http://adsabs.harvard.edu/abs/2012AAS...22043203S