"Hello, Operator. Mis-information, please."

I really try to be positive in my blog postings. As I have said before, there are enough cranky, crabby blogs out there, and this will not be one of them. But once in a while something is going to come up that ruffles my feathers and I'm going to be tempted to get cranky. Well, it's happened again. I'll try to use restraint.

This all revolves around the recent postings regarding the "supernova" V589 Puppis, that was "missed by legions of star watchers around the planet".

The only things remarkable about this story are 1) the fact that for the first time in history, a galactic nova was discovered by its x-ray emissions months after the initial outburst and 2) that this was so inaccurately reported 10 months after the fact by one of the more respectable astronomy sites in the universe today.

Here is the condensed version of the story with links to more information if you wish to investigate further. In October of 2007, the satellite XMM-Newton serendipitously discovered a transient x-ray source as it was slewing from one target to the next. This is known as the XMM-Newton Slew Survey. It's a clever way to maximize the use of the satellite. They're doing a survey of the sky even as they slew from one scheduled target to the next. This initial discovery was announced in an Astronomers Telegram in mid November. At this point all they knew was that it was very bright in x-rays, probably in our galaxy and might even be relatively close.

To follow up on this discovery a search for an optical counterpart was conducted. A normally 16th magnitude star in the vicinity of the x-ray event was identified as being brighter than normal. Spectra were taken of this star revealing emission lines typical of a galactic nova. Further investigation of the All Sky Automated Survey (ASAS) data for this star showed a couple lucky data points that the survey just barely managed to catch. The ASAS light curve, especially if it had a few more points in the declining part of the curve, would look very much like your typical nova. Case closed, the spectra indicate nova and the light curve says nova. It's a nova. NOT a supernova.

Unfortunately the sloppy reporting of this even reaches to the European Space Agency's XMM-Newton page where they write "Having been identified as a nova, the star was designated V598 Pup by the IAU." Actually, it is the General Catalog of Variable Stars (GCVS) that assigns names to novae, not the IAU. And thank God for that, seeing as how the IAU can't even figure out what to call Pluto and her friends. But that is another story for another cranky blog.

There's more! Many of the articles written about this discovery claim it must be some kind of miracle that this 4th magnitude, naked eye event wasn't noticed by the droves of amateur sky watchers and nova hunters looking up at the sky in June last year. I'm sorry, but any amateur astronomer who actually looks at the sky can tell you that in June and July Puppis is essentially in conjunction with the SUN! It's up during the day. You can't see it from Earth. The Sun is in the way! That's why I said the ASAS points were 'lucky'. That's also why they missed the rapid decline phase in July.

Only a professional astronomer who only observes with a space telescope would boldly claim “Anyone who went outside that night and looked towards the constellation of Puppis would have seen it.” C'mon, dude. The reason you didn't find it until months later is because you can't point your space telescope anywhere near the Sun or it will blow up. Not any more then I can see Puppis at night in June.

Now that would be a miracle.

6 comments:

Sebastian said...

Hi, Mike.
My "official" Puppis season ends on July 25 or so. I was observng L2 Pup and a couple of other stars nearby on June 4 and June 10. On June 4 the star was probably already visible.. :((.But I automatically went all the way to L2 and made my job...
Aout the maximum magnitude of V598 Pup it is interesting to note that at those magnitudes ASAS-3 is saturated.
The 4.05 figure for June 5 translates to a V-mag of 3.6 +/-0.2 mag.
Cheers

Mike Simonsen said...

Hi, Sebastian!

As anyone who has even heard of you knows, you are a dedicated, top shelf observer, unafraid of observing near the horizon to get those all important data points as variables go into and come out of conjunction. You also live in Argentina! From here in Michigan, and many other places in the north, Puppis is lost to us much earlier than July.
I did notice the large error bar on the ASAS curve. Thanks for translating that to a reliable V mag.

Ian Musgrave said...

Umm, Mike. At 5 June, when the article says the Nova happened, Puppis is 45 degrees above the horizon at astronomical twilight in my part of the southern hemisphere. For at least the first half of June, anyone in the Southern hemisphere wandering out in the early evening between 7 pm and 9 pm could have seen it. Puppis is star rich though, and could easily be missed.

Ian Musgrave said...

Comet Boattini!!! Where was every semi-serious southern hemisphere amateur astronomer looking in the first half of June? At comet Boattini, WHICH WAS JUST UNDER PUPPIS! My Sketch book has entries for June 3 and June 9, bracketing the June 5 date (and I looked on other days when I didn't sketch). When locating Boattini I scanned through Puppis, and used some Puppis stars as magnitude. FRACK! I just checked the location, I would have scanned straight over it while doing my magnitude estimations AND I DIDN'T NOTICE!!

I feel, I don't know, so unastronomical.

Ian Musgrave said...

Of course, the nova was in 2007, and we were watching in 2008 (now I feel really stupid). But the point is that us southern hemisphereians could have seen it, as Puppis is quite high enough to pick out 4th magnitude objects well after astronomical twilight. Just .. not on June 5 2008(sighs)

Stuart said...

Hi Mike. Assuming my planetarium software isn't totally wrong, if somebody was in a location on the Earth where they could see Puppis in early June - say, Australia, New Zealand etc - they would have been able to see it.

Of course it was sloppy English to imply that everyone on the planet would have been able to see it at night. There are times when us northern hemispherians make similar badly worded statements about things that people like Ian Musgrave can't see because they are too far south.