Loading ...
Sorry, an error occurred while loading the content.

Re: [comets-ml] Re: C/2005 P3 (SWAN)..&..Venus

Expand Messages
  • Rodney Austin
    Hi Piotr and Don, Thanks for your comments which have been very useful with this little curiosity. NGC 1841 is the most southern globular @ -84, and it was
    Message 1 of 8 , Aug 31, 2005
    • 0 Attachment
      Hi Piotr and Don,
      Thanks for your comments which have been very
      useful with this little curiosity. NGC 1841 is the most southern
      globular @ -84, and it was interesting to actually pick it up.
      Certainly it looked exactly like my last beast and about the same mag.
      Tirion also gives it a diameter of 2', whereas I could detect it out
      about 5' in the early hours of this morning. Again an effect of visual
      observing compared to those old 'blue' plates of long ago. It was
      particularly the wide difference in quoted mags that got me a bit
      startled. Normally I have found globulars at least are reasonably
      consistent. Planetaries are a different order of nuisance value. I
      write as a comet-hunter of course.
      I must complain about the weather more often. I got two mornings in a
      row, and tonight looks even better at this point.
      Cheers
      Rod

      On 9/1/05, tricks46 <Tricks46@...> wrote:
      > --- In comets-ml@yahoogroups.com, DonM353259@a... wrote:
      > > Greetings Rodney;
      > >
      > > Over the years I have learned that the published magnitude for
      > galaxies and
      > > other nebulae are often fainter than what they seem to be through
      > the
      > > telescope. The published magnitudes are sometimes related to
      > photographic guesses.
      > >
      > > Meanwhile, us comet hunters and comet observers are used to "total
      > > integrated magnitude", that is, the brightness of the comet is
      > equal to a star of the
      > > same brightness out of focus. Therefore, I have been saying for
      > some time
      > > that a comet of mag. 11.0, for example, is fainter than a galaxy
      > of magnitude
      > > 11.0!
      > >
      > > As an example, how many amateur astronomers went out to see
      > Periodic Comet
      > > Tempel 1 at magnitude 10.4 last July 3 only to not be able to find
      > it at all?
      > > And they were using telescopes that "see" galaxies to magnitude 12
      > or 13.
      > >
      > > There is another effect that occurs too while comet hunting that I
      > believe
      > > has to do with the degree of condensation of the object, usually a
      > galaxy. I
      > > have sometimes found some faint galaxies as I approach twilight and
      > am getting
      > > near the horizon. These objects have a brighter core than outer
      > portions
      > > (most do!), and I suspect the eye picks up the core, then begins to
      > notice
      > > (through adverted vision) the outer portions, at that point you
      > recognize they
      > > object as a fuzzy.
      > >
      > > Finally, I have found that eye, sky and telescope determine how
      > faint a
      > > fuzzy one can see, perhaps the importance of them is in that order.
      > >
      > > Take care.
      > >
      > > Don Machholz
      > > Colfax, CA.
      > >
      > > P.S. I notice that Comet Swan passed near Venus. I'm not surprised
      > it was
      > > missed, it is difficult to see much near the bright Venus, which is
      > usually
      > > seen only in twilight. Moreover, we do not know how bright the
      > comet was prior
      > > to discovery, some comets brighten rapidly (turn on quickly) prior
      > to
      > > perihelion.
      > >
      > >
      > > [Non-text portions of this message have been removed]
      >
      > Thanks Don! Good to see your post. Thanks, Mike H.
      >
      >
      >
      >
      >
      > NOTICE: Material quoted or re-posted from the Comets Mailing List should be
      > indicated by:
      >
      > Comets Mailing List [date]
      > http://www.yahoogroups.com/group/comets-ml
      >
      >
      > ________________________________
      > YAHOO! GROUPS LINKS
      >
      > Visit your group "comets-ml" on the web.
      >
      > To unsubscribe from this group, send an email to:
      > comets-ml-unsubscribe@yahoogroups.com
      >
      > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
      > To unsubscribe from this group, send an email to:
      > comets-ml-unsubscribe@yahoogroups.com
      >
      > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
      > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
      > ________________________________
      >
    Your message has been successfully submitted and would be delivered to recipients shortly.