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Re: Wild Speculation
Brad Schaefer published a paper in the Astrophysical Journal (Ap.J. 337,
927-933, 1989 Feb 15) entitled "Flashes from Normal Stars".
That was some 14 years ago and I'm not sure what happened subsequently as I
haven't done any literature search on the subject but it was certainly a
thought-provoking paper and well worth a read. How did the astronomical
community react to Schaefer's suggestion??
In that paper, two mechanisms were considered to explain the observed
One involved the reconnection of a star's magnetic field' - i.e. where a
large part of the energy stored in a star's magnetic field is released.
The second involved the impact of an asteroid (or comet) onto an unobserved
white dwarf companion.
(Not sure why a white dwarf has to be postulated here - I would have thought
that impacts by massive comets or planetesimals loose in interstellar space
could also be considered). The frequency rate estimated was of the order of
once per century per normal field star.
I tend to favour the comet / minor planet / planetesimal impact as our
knowledge of these bodies is very sketchy and there may be some regions in
our galaxy where the equivalent 'Oort Clouds' are relatively highly
populated with large bodies so we can't use our Sun as a typical example.
Indeed, that life evolved here may be evidence that our circumsolar
environment is atypical.
Hope this helps.
Maybe others may have another angle on this.
----- Original Message -----
From: Tom Droege <firstname.lastname@example.org>
Sent: Monday, May 19, 2003 11:55 AM
Subject: Wild Speculation
> First, I am encouraged that the data is picking up real asteroid crossings
> of stars in the data base. This gives me some confidence in the data. No
> doubt we could track this asteroid (and others) with the single hit data.
> So far, we have a sample of two. One is an asteroid, the other is
> unknown. Is anyone interested in looking at more examples?
> I could search the data for stars that have 10 or more measurements with
> one or more high points. My dumb approach would be to compute sigma for
> the measurements of each star and then look for 5 sigma high points. I
> could probably do this in a couple of days. My guess from manually paging
> through the data is that I might get a couple of hundred objects from my 2
> million star list.
> Would anyone want to work on this data set if I make it?
> Even better, does someone want to write a perl script that will process
> data file and output a string or interesting star measurements? I can do
> this, but it will take me a few days. I suspect that most of you can
> it off in 10 minutes. OK, the actual file that I have is called
> collected.t and is the result of merging the .cal files, sorting, removing
> flagged entries and processing the result through collect_stars.pl.
> In a spirit of fun, I will give the first person who sends me a working
> perl script a week head start on the resulting data. Send me a script, I
> will send you a data set. It should be small enough that I can just
> it to an e-mail. I reserve the right to allow ties if I don't get back
> reading my e-mail soon enough.
> The format was presented in the post. I will answer any questions about
> it, but it is well defined by collect_stars.pl which is available on the
> home page.
> Tom Droege