120 Galaxies Per Hour: A Personal Experience
By Steve Mencinsky, 1992
There are those that believe that there is no place in amateur astronomy for this kind of high-speed observing. This article is not for them - their paradigm will be too severely shaken.
The scene starts at the house at Ilford, 9pm, Sunday 1st March. The 12" f/4.8 dobsonian has been set up and the night is promising : seeing is good to great (six stars in the Trapezium of Theta Orionis, clearly and steadily visible since before it was completely dark); a moderately easterly wind (blocked out most effectively by a temporary wind shelter); low cloud far away on the eastern and southern horizon; transparency not great by Ilford standards; but still not bad (Gordon Garradd claims this is due to a recent eruption of Mt Hudson in South America). Being the only person at the site, the recurring thought was: as usual, the observing looks like it could be quite good when the rest of the guys are not here.
Darkness duly fell and I started observing at the usual leisurely pace until around 10pm, when an unknown vehicle arrived under parking lights and a dark shape emerged. An exchange of "Who's this? / I'm..." revealed the presence of Bob Evans, who had arrived to do a night's supernova searching.
Consider supernova searching. The key here is speed: to cover as many galaxies as possible. If you can memorise the locations and surrounding close-in star fields of thousands of galaxies, clearly the use of time will be very effective indeed. The difficulty is obviously in the memorising. Can't be done, you say? At the least, impractical? Tell that to Bob Evans. Bob HAS memorised locations of thousands of galaxies - and not only locations, but star fields, RA/Dec, galaxy type, overall magnitudes, magnitude of nucleus, etc, etc, etc.!
A polite invitation to Bob to help himself to the 12" for the night produced an observing night at Ilford that in my experience was without peer. We had challenges galore: several episodes of "Attack of the Killer Clouds" caused us to lose about three hours of observing; we were plagued by persistent heavy dew (Mick McCullach's closest friend) assaulting my home-made Telrad; Bob professed to be uncomfortable with the right-angle finder (although I would never have guessed), Bob's 16" is equatorially mounted so he claimed to be uncomfortable with the orientation of the galaxies in the field. Despite all of this, during the night Bob found and we duly observed some TWO HUNDRED AND EIGHTY galaxies, most of them in Virgo and Coma Berenices (because I had suggested that area of sky). Consider also that this involved TWO people observing at the eyepiece, one of whom (yours truly) was writing down NGC numbers and the occasional note, which slows the "galaxy rate" to less than half that of a sole observer. Clearly, had Bob been observing on his own, the rate would have been much higher. This whirlwind tour demonstrated unequivocally that the rate of 120 galaxies per hour (a figure that Bob casually mentioned) seems eminently - even easily - achievable.
And don't think that all the objects were easy ones! Most of the galaxies were common or garden variety NGC galaxies, but several were quite faint IC galaxies, a few were "A" or "B" galaxies (as in NGC 5846 and NGC 5846A), four ESO, two MCG, M51, and one galaxy (NGC 3184) in Ursa Major!
A veritable rain of objects came pouring through the eyepiece: galaxies large (M87) and small (NGC 4647), bright (M65) and faint (IC 4182), ellipticals of various orientation and ellipticity, spirals of various flavours (a handful even had arms well visible) and the glorious spindles, some with dark lanes - M64 and NGC 4565 being only the most obvious examples. Never again will I feel any subconscious guilt when derisive comments are made by the planet-heads about "faint fuzzies". The sheer variety of this plethora of extragalactic morphology was indeed an example of what Carl Sagan describes perfectly with his adjective of "numinous".
There were several galaxies in Leo that we were unable to observe due to glare from the unwelcome presence of one of my betes noir, Jupiter. Bob agreed that the planets were nothing more than an undisciplined and irresponsible menace, careening about the ecliptic as they do like bulls in a China shop, interfering with legitimate deep sky observing by hard-working amateurs. Greg Bryant and Tony Buckley - I hold you personally responsible for any supernovae that Bob may have missed as a result of this irritating interference by these celestial vagrants.
(Sweet and innocent voice: "Do any planetary observing, Bob?"
Brusque reply: "No. Now this large galaxy here is IC ...")
It is beyond my memory to single out any one item as the "best" for the evening, although on consulting my notes, the close pair NGC 4571 and NGC 4762 stand out as the only ones to record the highly sought after triple-exclamation-mark (as in "Wow!!! Eta Carinae!!!). What does remain in my mind, clear as the proverbial bell, is Bob's boundless enthusiasm, navigational skills, and prodigious feats of memory.
Johannes Kepler, my "all-time greatest" astronomer, proved in another age that the orbits of even the most obstreperous planets such as Mars could be calculated - and even predicted - through nothing more than sheer dogged application of mind and will power. Exactly how much effort was required has been hammered home to me by my stumbling attempts to duplicate Kepler's work on the ubiquitous and all-powerful computer. To my mind, Bob has shown the same kind of application, albeit in a different direction. Both richly deserve their rewards.
(Carl Sagan describes the meaning of "numinous" in breathless detail in his great work of fiction, "Contact").
(Reprinted from Universe, March 1992)