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I find it interesting that there is no chatter about this on any of the variable star organisations or alerts so wonder if this is a false alarm. RX And is a dwarf nova system.
Owen
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2020-11-19, 05:39 PM
(This post was last modified: 2020-11-19, 06:29 PM by theskyhound.)
Hi Phil & Owen,
I saw this myself recently and I'm looking into it now. The magnitude is in error, especially if you look several months into the future.
In ST4, I implemented a complicated scheme for handling novae and supernovae. Its probably the coolest (or perhaps the "nerdiest") part of ST4. Very few people are even aware of it. The root of the idea was that large numbers of supernovae are being discovered these days, and I wanted to add them to SkyTools and plot them on the charts. The problem is that after a while, the supernova fades but SkyTools 3 will still show it. SkyTools 3 would also show it long before it brightened. So what ST4 does is to assign a "light curve" to each of these stars based on one or more samples of its magnitude and a generic curve that most stars of this type follow. The magnitude of the star at any time is determined from the light curve. So if you come back three years after the supernova, it will have faded in SkyTools such that it will no longer be visible. It does the same thing with classical novae, like RX And.
There are a lot of variables in this system (pun intended) and even though I have watched the results for several years now, and it has been working fine, apparently RX And has broken it somehow. I am doing fixes this week, and there should be an update with a fix for this soon.
By the way--try looking at Taurus in January of 1055 AD!
Clear skies,
Greg
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I did check Wikipedia for RX And info. That indicates a normal mag range of ~10 - 15, so the brightness reported by ST4 was anomalously high. That's too bad, it would have been cool to get a nova this bright.
Phil S.
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My apologies. Next time though!
Clear skies,
Greg
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Yee that Jan 1055 chart is pretty cool with the SN going off. Must try the Lupus one in 1006 :-)
Owen
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(2020-11-20, 11:09 AM)obrazell Wrote: Yee that Jan 1055 chart is pretty cool with the SN going off. Must try the Lupus one in 1006 :-)
Owen
Sadly, I don't think I got that one in there.
Clear skies,
Greg
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no you didn't, but at mag -8 or so it would have been fun to see :-)
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As you know, we are rather overdue for another one of these. One of the days!
Clear skies,
Greg
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I see the SN at the position of the Crab Nebula on 4 Jan 1055, but ST4v (4.0j) identifies the object as the Cone Nebula. The incorrect ID only occurs at a 60° zoom level or higher. At zooms of 30° or below the Crab Pulsar is identified. The mag of the SN isn't provided.
What am I missing?
Phil S.