HCG 50 observed with 30"

From: Randy Muller (rmuller@No-Spam)
Date: Sat Feb 22 2003 - 18:54:00 MST

  • Next message: David Kingsley: "OR: Fremont Peak 2/21/03"

    Three of us (Brian Zehring, Alvin Huey and I) were able to observe at
    least one component of HCG 50 last night at Blue Canyon (5284'),
    February 21, 2003. This is by far the most challenging of the Hickson
    Compact Groups (of galaxies) to observe, and is probably not observable
    by ordinary mortals in scopes smaller than my 18".

    We used Brian Zehring's mammoth 30" f/4.3 Starmaster, which also
    happened to be getting its official first light.

    Using a 13mm Nagler (252x), we were able unambiguously to find the
    proper field, which is located only 21 arc minutes nearly due east from
    M97, the famous Owl Nebula.

    The field itself is not only easy to recognize, getting there is easy as
    well: 12' mostly east and slightly south of M97 lies a
    fairly bright trapezoidal figure about 5' across consisting of two mag
    10 stars (TYC 3825-19-1 and TYC 3825-27-1) and two mag 12 stars (TYC
    3825-24-1 and TYC 3825-22-1).

    Continue east 5' from TYC 3825-22-1 to arrive at the mag 13 star
    GSC-3825-0023. This forms one corner of a triangle with GSC-3825-0104,
    almost 3' further east. The third corner is a mag 17 star (USNO-A2.0
    1425-07637517) located at 11h 17m 5s +54d 54m 51s.

    I gave a little hoot when I saw this object at the third corner, because
    I thought at first it was one of the components of Hickson 50. Alvin
    had a DSS photo of the field, showing a tiny (and I do mean tiny) oval
    of 5 galaxies, with a more stellar-looking object outside the oval.
    This object was in exactly the same position as what I was seeing.

    This star could be held easily and steadily with averted vision.

    It was evident to Alvin and me that we needed more power, so Brian
    popped in a 6mm Nagler (546x), and we began to examine the field very
    closely for extended periods of time.

    Alvin studied the field while I went back to my chart (sans the dim
    galaxy-like star) to verify once again that we had the right field.

    When Alvin was done, I mounted the ladder and studied the field.

    I intermittently (perhaps 10-25% of the time) observed an extremely
    faint fuzzy patch a small distance (about 20") at about the 11 o'clock
    position from the mag 17 USNO star (12 o'clock being straight up). At
    our local time and latitude this was NE of the USNO star. The fuzzy
    patch seemed to be multiple objects, but how many was impossible to say.

    Alvin observed the same patch in the same place and seemed to think it
    consisted of 3 galaxies.

    HCG 50A is offset 15-20" roughly NE of the mag 17 USNO star.

    For an Aladin visualization of this field, see

    http://nedwww.ipac.caltech.edu/cgi-bin/Aladin/nph-aladin.pl?frame=launching&-c=11+17+06.40000+%2B54+55+01.0000&-rm=3.50&-server=NED%2CVizieR&-source=USNO2&img=http%3A%2F%2Fnedwww.ipac.caltech.edu%2Fdss%2F%2FHCG_050A_3.fits.gz+Palomar48-inchSchmidt%3A103aE



    The Astronomy Connection -- Mailing List Archives