The designs of astronomical telescopes for comet discoveries
have been explored for more efficiency and functionality throughout the
times. It was for more comfort for long continuous observing. Commercially-made
telescopes did not meet this requirement. For comet hunters, building a
comet seeker is part of the enjoyment of comet search. The important conditions
for the comet seeker are 1) having a wide, clear field of view, 2) being
appropriately short focal, easy to sweep the sky, and portable. The altazimuth
mounting is easy to use, but to get the coordinates (RA and DEC) of an
unknown object the equatorial mounting is naturally advantageous. A great
comet seeker equipped with these seemingly conflicting merits of the altazimuth
and equatorial mountings actually existed at Tokyo Astronomical Observatory
in the past. The existence of this comet seeker is a mystery, though.
Earlier, I said there were no commercially-made comet seekers
available, but the only exception is the Zeiss 20cm (triplet) f/6.7 comet
seeker. As the one at the National Astronomical Observatory does not retain
its original appearance today, few people know what it looked like initially.
This short focal refractor was fitted with an appropriate height observing
chair and designed to sweep the sky along the Right Ascension while changing
altitudes. The position of the eyepiece did not shift much, so search was
comfortable. When you find a come-like diffused object using the lowest
effective magnification, it will be difficult to determine if it is a small
open cluster or hazy nebulous object. Unfortunately, large binocular telescopes
popular for comet search these days have this problem with a fixed magnification.
With the Zeiss Comet Seeker the magnifications were changeable
from 27 to higher than 100 power. The Achilles heel of the altazimuth comet
seeker is the difficulty to determine the position of the object discovered.
You would be extremely frustrated when you discovered a comet in twilight
and could not see the background constellation clearly. It would be hugely
advantageous if the comet seeker was equatorially mounted. And you would
be surprised to know that this Zeiss comet seeker was on the equatorial
mounting! Who in the world designed this ideal telescope and what motivated
them to bring it to the Tokyo Astronomical Observatory? This will be an
unresolved mystery forever.@
In the autumn of 1961, the former President of Oriental Astronomical
Association (OAA) Kyoyu Kudara gave a talk on comet search at a regular
meeting in Osaka. Prof Kudara was a distinguished scholar, but actually
searched for comets himself and independently discovered Comet Temple 2
in December 1919. During the talk I remember he referred to Tokyo Observatoryfs
comet seeker and said that it was unknown why the observatory acquired
this comet seeker and that possibly the Zeiss gthrew it inh when the 60cm
refractor was purchased.
It is well-known that Mr. Shigeru Kaho, a staff member of
the National Astronomical Observatory, discovered Comet Kaho-Kozik-Lis
(1936 III) using this comet seeker. According to Mr. Koichiro Tomita of
the National Astronomical Observatory, Mr. Kaho discovered this bright
comet (6-7th magnitude) by chance during the observation of variable stars
in the evening sky. In those days there was no award system in place in
the Astronomical Society of Japan, but he received a letter of commendation
from the Society. In the 18th to 19th Century, comet discoveries were frequent
in the U.S. and Europe. Looking at the situation like this the world renowned
Zeiss might have designed and built comet seekers like the one at Tokyo
Observatory. As a comet seeker it must be one of the finest in the world.
I wonder if a Zeiss comet seeker contributed to the discovery of a comet
anywhere else than at Tokyo Observatory. There is no way to know it. As
for the destiny of this Zeiss comet seeker, I remember that, when I visited
Dodaira Observatory in the 1960s, I saw it mounted on the Baker-Nunn Satellite
Tracking Camera for a finder scope. I suspect there was no one there to
use it for comet search and it was used for a different purpose. I wanted
to check the image quality of the telescope, but have never had a chance.
Although I heard that image was not good, I am not sure if it is true.
Mr. Masamitsu Yamasakifs comet seeker is well-known for his
1928 discovery of Comet Crommelin. The unusual design of the focuser being
positioned on the altitude axis originated in the U.S. Around 1953 I visited
Mr. Yamasaki in Sagawa, Kochi prefecture and had an opportunity to look
through his comet seeker. The eyepiece used on this telescope was an old
Ramsden design with a narrow apparent field of view of 30 degrees, while
the true field of view was 1 degree. The width of the field was so narrow
I thought it would be miraculous to be able to find a comet.
About 10 years ago, I attended a comet conference in the
northern Japan. There was one very enthusiastic local comet searcher and
he talked about his observing facilities and equipment. His small dome
has a heater and was equipped with a modern 15cm binocular comet seeker.
It is connected with a PC, which displays the RA and Declination as well
as star clusters and nebulae easily mistaken for comets in the target area.
It was a well-thought-out, ideal modern equipment, but the success rate
for comet search with it was ironically not necessarily proportional to
the level of the equipment. Since the days of Messier and Bonn Observatory
what has achieved the greatest results was the search simply by using a
small easy-to-operate come seeker and star charts one is used to, and,
of course, the cold winter skies outside as well.
Mr. Minoru Honda conducted come search seriously using a
15cm comet seeker over a period of 10 years between 1940 and 1950. It took
place in the mountains of Setomura of Hiroshima prefecture. It was the
same place where zodiacal light observation post had been operated. Initially
he used a 10cm reflector with a Sakamoto mirror, then switched to a 15cm
f/6.3 reflector with a Kibe mirror. I think the mounting was home-built.
It was an ordinary altazimuth reflector with a 40mm Kelnner eyepiece which
delivered a 1.5 degree field of view at 23x. This mirror figured by Mr.
Kibe seemed to be one of his best and proudest and the image quality was
extremely high. The sharp star image is a very important thing for comet
searchers. Mr. Honda discovered two comets using this comet seeker, one
in 1947 and the other in 1948. (A third was a naked-eye discovery of 1947
IV). In those years, many comet searchers must have dreamed about his 15cm
f/6.3 comet seeker, which was considered to be a standard telescope for
According to letters from Mr. Honda, observers who were conducting
comet search at his time were Mr. Einosuke Asano of Yamaguchi prefecture
and Busho Kawando of Kagawa prefecture. Another observer, not well-known
then, was Mr. Tetsuyasu Mitani at Kwazan Observatory. He searched for comets
using a 12cm f/5 refractor at 15x for half an hour until the dawn break.
Though he had a 3-degree field of view, he was lamenting that faint stars
were difficult to see. These observers maintained close contact with Mr.
Minoru Honda. I was one of those observers and very interested in Mr. Hondafs
comet seeker. However, I didnft have a chance to look through his 15cm
comet seeker. However, Mr. Honda wrote me an exciting letter saying: If
you wish, I will ask Mr. Kibe to grind a mirror for you with the exactly
same configuration and quality as mine. My wish to see Mr. Hondafs comet
seeker was answered.
Incidentally, when I successfully discovered Comet 1961f
in October 1961, there were a number of observers who placed special orders
for lenses with exactly the same configuration as my comet seekerfs 88mm
f/7 lens. Using these lenses, Mr. Toshio Haneda of Fukushima prefecture
and Noboru Nishikawa of Minamata city succeeded in finding comets. Any
comet hunter may wish to have a comet seeker, the same as those used by
successful comet searchers. It may be just a superstition or a wish for
luck. As you can imagine, a lot of comet hunters dreamed about owning a
telescope like Mr. Hondafs 15cm comet seeker. And, I own one with exactly
the same configuration as his. Mr. Honda had his comet seeker at his home
in Hiroshima prefecture at least until around 1953, according to him.
The view through the 15cm f/6.3 reflector was incredible.
Owing partly to the dark sky over Kochi city, each one of star clusters
and nebulae was as impressive as photographs taken by a large aperture
telescope. I was mesmerized and numbed by profound and mysterious world
of the stars, gazing at numerous celestial objects, these objects that
Mr. Honda himself looked at and yelled with delight and excitement.
My 15cm telescope was actively engaged in initial observation
of newly discovered comets and in October 1956 I succeeded in the independent
discovery of Comet Crommelin, which had returned after 23 years. With the
achievement I had made, Mr. Honda offered me more support by sending me
a copy of hand-drawn, not publicly available Skalnate pleso Atlas of the
Heavens by A. Becvar (1950). I remember fondly too that Mr. Kunio Kenmotsu
of the Maritime Safety Agency was mentioned in Mr. Hondafs letters to me
around that time.
In the summer of 1950 Mr. Honda left his successful observing
site Setomura for Kurashiki city. In 1953 he discovered his long-awaited
6th comet Mrkos-Honda using his 10cm binocular telescope. It was in September
of the following year of 1954 that I visited Kurashiki Observatory for
the first time. At that time the 13cm equatorial refractor and 31cm Culver
telescope were there, but for some reason I could not find his 15cm comet
seeker. You would expect that telescope to be actively engaged in comet
search. Instead, I found a small 10cm binocular telescope sitting on a
motorized floor in a one-meter-diameter silverly dome. The scope was manufactured
by Kowa for astronomical observation and had been found by the owner of
a Kyoto optical company. I asked Mr. Honda: gIs it good?h. He replied:
gThe focused image is terrible. If I look through it for a long time, it
makes me dizzy and sick. I make it a rule not to search for a faint comet
but to look for a comet brighter than the 8th magnitude. I wondered why
Mr. Honda persisted in using this binocular telescope. He was particular
about the focused image and said that in order to make a discovery the
sharp focused image was paramount. And he wrote so in some publications
as well. Perhaps, he preferred the advantage of using both eyes. Perhaps,
his 15cm reflector was no longer with him. In fact, all the discoveries
after that had been made by other than his 15cm telescope. Mr. Hondafs
renowned telescope now vanished from the world of cometary search. It seems
as if his 15cm f/6.3 comet seeker had been reborn and is now in my possession.
This 15cm comet seeker in my hands imbued with Mr. Hondafs spirit has been
used for numerous observations of comets culminating in the 1967 discovery
of Comet Ikeya-Seki 2 (1968 I). Immediately after that, it was equatorially
mounted. This Comet Ikeya-Seki became the first comet photographed by this
15cm telescope. With the SAO Star Catalogue having become available, I
began astrometry of comets and minor planets using a home-built comparator.
My 15cm come seeker became the telescope to commemorate the start of my
astronomical observation for the coming decades. But again where has Mr.
Hondafs 15cm comet seeker gone? The story of this comet seeker will continue.
In Part 23, I will tell you the story of ga visitor on one
Copyright (C) 2019 Tsutomu Seki.