Sky Patrol All-Sky Automated Survey for Supernovae
Find Right Ascension and Declination by Star Name
We have updated Sky Patrol to provide three Photometry methods:
- Aperture photometry. This does aperture photometry directly on the individual images. This is the original Sky Patrol photometry method.
- Image Subtraction (reference flux added). This does aperture photometry on the coadded, image subtracted data for each epoch and then adds in the flux of the source on the reference image.
- Image Subtraction (No reference flux added). This does aperture photometry on the coadded image subtracted data for each epoch but does not add the flux of the source on the reference image to the light curve.
Because the image subtracted light curves use the coadded data for each epoch (usually 3 images) while the aperture photometry light curves used the individual images, there will be fewer points but with deeper flux limits. When the reference flux is not added, the light curves will have both positive and negative fluxes because it is the change in flux relative to the reference image. Because it can be both positive and negative, these light curves can only be defined by flux and not magnitudes.
We are now serving both V-band (Cameras ba-bh) and g-band (Cameras bi-bt) photometry, see "Examples" link below for details.
V-band and g-band magnitudes obtained via this page are calculated in real-time using aperture photometry, with zero-points calibrated using the APASS catalog. ASAS-SN images have 8" pixels (~15" FWHM PSF,) so blending/crowding might be significant in some cases. The "Examples" page linked below, and Kochanek et al. (2017) paper, illustrate some of the potential problems. Always proceed with caution before publishing. This page is meant to obtain a relatively small number of light curves - if you need light curves of many (>100) objects, please contact us.