IAU Central Bureau for Astronomical Telegrams

Central Bureau for Astronomical Telegrams -- Image credits

IAUC 2209: REPORT ON THE 2.7-METER REFLECTOR; 1969h

The following International Astronomical Union Circular may be linked-to from your own Web pages, but must not otherwise be redistributed (see these notes on the conditions under which circulars are made available on our WWW site).


Read IAUC 2208  SEARCH Read IAUC 2210
IAUC number


                                                  Circular No. 2209
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Cable Address: SATELLITES, NEWYORK
Western Union: RAPID SATELLITE CAMBMASS


REPORT ON THE 2.7-METER REFLECTOR
     Dr. Harlan J. Smith, Director of the McDonald Observatory,
University of Texas, communicates the following: "In view of highly
exaggerated and incorrect news stories of grave damage to the 2.7-m
(107-inch) McDonald Observatory reflector, a prompt summary of the
facts may be of interest to the astronomical community.  Shortly
before CST midnight Feb. 5 (Feb. 6 UT), a newly-hired employee
fired seben point-blank shots into the front surface of the fused
silica primary mirror, using a 9-mm pistol apparently brought with
him from his previous home in the north.  He has been committed by
local authorities to a state mental institution, on ground of
insanity.  The harm suffered by the mirror from his bullets and his
several preliminary blows with a hammer was extraordinarily small.
The damage is limited to small craters about 3 to 5cm in radius,
which reduce the light collecting efficiency by about 1 percent and
introduce a very small amount of diffraction.  Surface and Foucault
examinations by Mr Donald Davidson and Dr. Robert Tull, the opticians
responsible for producing the mirror, show that there is no
change of figure.  Astronomical observations of all types are
essentially unimpaired by this tragic episode; the telescope resumed
its observing program the following night, producing some of the
best photographs (of quasar fields) so far obtained with this
instrument in its first year of use".


PERIODIC COMET CURJUMOV-GERASIMENKO (1969h)
     Further precise positions have been reported as follows:

     1969/70 UT          R.A. (1950) Decl.       Mag.   Observer
     Nov.  9.81944   10 18 05.92   +17 47 08.2          Candy
     Dec.  9.83229   11 12 07.25   +15 03 23.4   14     Seki
          18.83652   11 22 07.90   +14 47 02.9            "
          20.83576   11 23 55.72   +14 45 56.0            "
     Feb.  4.08359*  11 20 08.91   +18 01 42.0          Milet
           4.09120*  11 20 07.81   +18 01 48.7            "
           4.09466   11 20 07.76   +18 01 47.1            "

M. P. Candy (Perth Observatory).  33-cm f/10 astrograph.
T. Seki (Kochi Observatory).
B. Milet (Nice Observatory).  *Weak images.


1970 February 10               (2209)              Brian G. Marsden

Read IAUC 2208  SEARCH Read IAUC 2210


Our Web policy. Index to the CBAT/MPC/ICQ pages.


Valid HTML 4.01!