errors in the brightest absolute mags about astrocats HOT 6 CLOSED

@mnicholl Thanks very much for the extensive error-checking!

The common denominator for most of the problems is the Latest Supernova page, I have noticed a much higher incidence of errors from that page, which is understandable since David is just transcribing the ATels by hand. I'm actually probably going to change the script such that no magnitude information from that page will be imported if there is information available from any other source. For SNe for which there is no other data we'll continue to draw from that page, since David's information is correct the majority of the time.

From Sternberg I've also noticed some errors too in the past, but generally not as many. Sternberg is the largest single source by far of light curves, and most of their data is right, so I'm not too concerned. It's great though that you're finding the erroneous data, I'll check the individual events you mentioned to see if I can find a pattern in the error.

As for GRBs: Not clear to me where they fit on the supernova page in general, in principle all LGRBs have a supernova counterpart which we may or may not see, and hence are technically "supernovae" which I feel we should keep track of. But I agree the peak maximum mag should be based on the supernova light curve, not the GRB.

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Oh one last comment: I'd love to pull directly from ATels, but unfortunately they are written in plain English and are not easily machine-readable. This is why David Bishop is so valuable, he transcribes these for us, the downside being that he sometimes makes mistakes.

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@mnicholl So I think I figured out the Sternberg issue: 2001iw, 2002ab, 2001iy, 2001jp, 2001fo, etc. all come from Barris 2004: http://adsabs.harvard.edu/abs/2004ApJ...602..571B, there are 21 LCs that originate from that paper. It looks like in that paper that the light curves are presented as fluxes, not magnitudes (there is a VizieR table for this data), and I'm betting that Sternberg misconverted this data into magnitudes. I'll ban the Barris data from import for now until we resolve the issue.

It would probably be good to reconvert this data to magnitudes anyway from the fluxes since there are errors reported for the fluxes, which Sternberg did not take into account when they did the conversion (none of those magnitudes have error bars). Do you have any suggestions for an accurate way of converting the flux+errors into magnitudes+errors?

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Some fixes here which will appear after the next import (in about a day), I linked many of the changes so you can see how these changes were done @mnicholl:

• Magnitudes not added from Latest Supernova page if GRB is listed as an alias.
• LSQ12axx and SN2004cq's erroneous redshifts now ignored from LSNe, correct redshift added for LSQ12axx.
• SN1998ev's LSNe photometry removed, new magnitude added.
• Added "QSO?" to SN2001bu, object won't be removed from list but will at least be listed as being suspicious. The "Q" appears in some host names of some legitimate supernovae, so I'm not sure if that's a good metric for removing events.
• Added QSO type to PS1-12qh, will be removed.
• Barris 2004 data drawn from ITEP now being ignored, added Barris 2004 to to do list.

A few "won't fixes":

• For SN2001ca, I'm hesitant to remove it despite it only having one detection. It's possible data exists for the event somewhere that's not public. Policy is to retain all events with an IAU SN name unless they have a definitive typing as a non-SNe.
• CRTS data is definitely a bit flawed for some events but the CRTS data is drawn from their website which updates dynamically. In these cases I favor contacting the source of the data directly to inform them they have a pipeline issue, I've already seen with OGLE that bad points will "go away" as their pipeline is adjusted. However, one thing we could do is avoid using CRTS data if any other data is available for a given event when calculating the maximum magnitude, definitely will consider this.

And lastly a question:

• I don't have access to the CBET for SN2014W, but we support recessional velocities as inputs (they will be automatically converted to redshifts). What is the recessional velocity reported in that CBET in km/s?

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OK, everything except for SN2014W is resolved, attempting to get access to the CBET archive to address that one.

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Everything in this issue should now be resolved, closing.

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