[AZ-Observing] Re: McNeil's Nebula Images
- From: "Jon Christensen" <jonc97@xxxxxxx>
- To: <az-observing@xxxxxxxxxxxxx>
- Date: Fri, 20 Feb 2004 22:17:49 -0700
McNeil recently posted an excellent follow up image to
alt.binaries.pictures.astro he took of M78 and Hartmut Frommmert of SEDS
brought up the fact the nebula was found in earlier photographs. McNeil
posted this reply pointing out that although it is not 'new', noone else
noticed it:
----- Original Message -----
From: "Jay McNeil" <icnebulae@xxxxxxxxxxx>
Newsgroups: alt.binaries.pictures.astro
Sent: Thursday, February 19, 2004 3:53 PM
Subject: Re: Re: ASTRO: Messier 78 with new neb
Hi Hartmut,
Thanks for the kudos, and...
Yes, the object is obviously visible on the Kreimer's 1966
image. Furthermore, on the far-red/nir plate scans one can
see a very faint stellar counterpart to IRAS 05436-0007. As
a matter of fact, this object is very bright on the older
2MASS images. Furthermore, HH 22 (which happens to lie in
the exact same direction as part of the new nebula)also
shows as a small nebulous "blob" on deep images taken of
the area with infrared sensitive equipment. HH22 is
actually _just_ visible on the downloadable red scans even.
The fact that the young "stellar" object presently
undergoing eruption has existed and been known about for
some time is not a matter of argument--the fact that it
(and the resulting nebula) went from being all but invisible
in the optical range to one of the more conspicuous objects
in the entire field over a period of less than 3 months is
what's so striking and phenomenal about the discovery!
And regarding the earlier (1960's) images that distincly
show the object, it has been speculated for some time now
by Reipurth, Herbig, and others that such pre-main sequence
eruptions are indeed periodic in nature. The fact is,
however, that so "few" of these eruptions have ever been
captured this early on--I had read somewhere that the going
rate is one such observation every 6 to 7 years thus far.
Now, let's combine that with our complete lack of knowledge
regarding these speculated "periods" between such eruptions
for a given young stellar object. FU Ori went form mag 16
to 10 (where it still hovers nearly 70 yrs later) in just a
few months. Meanwhile, V1515 Cyg took several decades to
increase by only 4 mags. The rise and fall times of such
eruptions thus far recorded vary dramatically, just as the
periods between subsequent eruptions are specualted to vary
as well. So, in essence, it would actually make sense if
this star underwent a similar eruption some other time
within the past century. If this is proven so, then I
personally don't see that as being any sort of "negative"
aspect to my finding--just a very staggering achievement in
the calculation of such outbursts.<g>
With all sincerety, I was simply looking at the right
place at the right time--as with most amateur discoveries.
On the other hand, I have learned through experience
that "anyone" with enough money (to purchase the proper
equipment) and patience can take a suprisingly good CCD
image. However, knowing exactly what is going on inside
your image enough to realize that a peculiar 1' diameter
object doesn't "normally" belong there is not something
that I take for granted. After all, if the guy snapping
the Palomar Optical Sky Survey shots would've known that
George Abell would come along shortly after and find some
2712 new galaxy clusters and 86 new nebulae using his
prints, he would've likely been waiting outside the
darkroom door with a magnifiying glass in hand as the
plates were being developed! <G>
Jay McNeil
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