Visual comet hunter from "Land of the Rising Sun"
He accidentaly spotted a new comet at age 13 which led him to become a comet hunter. He stopped his quest when he entered a college and found a new hobby instead. 15 yeas later a bright comet restarted his search. Despite of big sky surveys he believed that comet hunters could survive. "See stars by heart", says visual comet discoverer, Shigeki Murakami.
You are a research scientist at the Forestry and Forest Products Research Institute. What do you exactly do there?
I am a forest hydrologist who studies the water circle in forest. Specifically, I am interested in two hydrological processes.
One is evaporation of rainwater at the time of rainfall. Rainfall under forest canopy is some 20% less than that of treeless site because of evaporation. If we have 50 mm of rainfall per hour, evaporation is about 10 mm per hour. In the US or Europe where rainfall intensity is generally low, scientists overlooked the fact. I have proposed a new mechanism to explain large evaporation during rainfall; splash droplets produced by raindrops impacting on the forest canopy evaporate. The conventional concept assumes evaporation from wet canopy surface, but it cannot explain the observational fact.
The other is snowmelt process in forest in relation with water resources. The later the disappearance of snow cover, the longer one can utilize snowmelt water. Forest cover reduces snow accumulation on the forest floor, because some portion of snow on the canopy evaporates. At the same time forest canopy delays snowmelt on the forest floor since the canopy reduces solar radiation and wind speed. I try to find the optimized forest structure that is useful in terms of water resources.
You began watching the stars as a kid at age 10. What had been the spark of your astronomy interest?
A friend of mine bought an astronomical telescope. It inspired me to do the same thing. There were three, including me, who wanted to become amateur astronomers at that time, and we have been enjoying stargazing for several years since then. Now, I am the only man who continue to observe.
Did not you consider to become an professional astronomer as a teenager?
Yes, I did. I was interested in various fields of science in my boyhood and once I considered to do so. Nonetheless, I reconsidered at the age of 15. I attended the Annual Comet Conference for the first time at that time where I met many famous comet hunters including Minoru Honda and some professional astronomers. After the conference, there was an excursion to Okayama Astrophysical Observatory, a branch of Tokyo Astronomical Observatory (at present National Astronomical Observatory of Japan, NAOJ), where the largest telescope in Japan was equipped then. Tooru Kobayashi, a discoverer of Kobayashi-Berger-Milon C/1975 N1, made a question to Professor Goro Ishida, the director. Kobayashi asked to Ishida, “Is your vocation enjoyable?” Ishida was confused and could not reply his question. I was impressed by Kobayashi’s question and I noticed that enjoying starwatching is one thing, and to study astronomy, is another.
I do not mean I decided not to become a professional astronomer at that time, but it is true that the incident was very influential. When I met Kobayashi at Annual Conference of Comet last year (2016), I asked him if he remembered that he made such a question to Ishida. He said he did not remember on it.
What was your main source of information about astronomy during the beginings?
The only information source in my early teen was a monthly magazine of astronomy: Temmon Guide. For example, it took at least one month to get information on comet discoveries. There were some circulars sent by postal mail as in "Yamamoto Circular" (published by Oriental Astronomical Association, OAA) and "Comet Bulletin" (Comet section of OAA). However, I did not subscribe to any of them in my early career of amateur astronomy, since I was not a comet hunter. In my mid teens when I began to search a new comet I subscribed one of them. I got information on new discoveries within about a couple of weeks.
In summer of 1975, I heard in the radio a news about a new comet discovery. That evening I searched for it with my own selfmade 2" refractor. I found a small speck bellow the Big Dipper, which was confirmed as C/1975 Kobayashi-Berger-Milon. You spotted it too, by chance. How do you recall to that?
Yes, I accidentally spotted it at age 13. Though I knew it is very challenging to discover a new comet, through this experience I had an impression that I could find one if I am lucky. It lead me to become a comet hunter.
The comet was bright at 6th to 7th magnitude and I presumed it must be a known one. Having said so, if the comet was getting bright in a short period of time, it could be a new comet that had not yet been reported. I knew what I should do upon discovering a new object. I positioned the comet using a star chart, A.A. Mikhailov Star atlas, which was the only map I had at that time. Then I made a phone call to Tokyo Astronomical Observatory (at present NAOJ). I was very nervous but it was set to the answering machine because of nighttime.
The next morning I had to attend the practice of the track and field club in my junior high school, though we were on summer vacation. I participated in the prefectural tournament as a member of 400-meter relay race two weeks later (we won the second place). I made the phone call again from the public phone in my school, and some friends who were interested in my discovery were with me. The connection was made and I told the positon of the comet to the person in charge. He replied coldly, “The comet has already been discovered some weeks ago named Kobayashi-Berger-Milon.” As I thought it turned out to be a known comet, but I was delighted to know a Japanese was the first discoverer. It was enough for a boy to be motivated to start comet hunting.
As a high school student you were supposed to go to school in the mornings. How could you manage to combine the school at daytime and hunting during nights?
I usually comet hunted at dusk only. That might be good in health for a teenager. A village I grew up was in a mountainous area, and at my house a large part of the eastern sky is hidden by a mountain. Therefore, it was difficult to search the eastern sky at predawn. When I sweep the eastern sky, I must carry my telescope with a wheelbarrow as far as 1 km where the eastern skyline is lower than about 15 degrees or less above the horizon.
When you entered college, the changed situation forced you to quit with hunting. What was the reason and was it a hard choice?
City of Sapporo where my college is had a population of 1.4 million in 1980’s. Even if I have had a car, it would have taken more than one hour and a half to reach a dark site. It disappointed me and I did not think about comet hunting. It was not a hard choice for me because I found another hobby like skiing and mountaineering.
So you found for yourself a substitute. Haven´t you looked at the sky all those years?
No, when I was enthusiastic about mountaineering, I seldom observed the night sky. Now, I sometimes enjoy mountaineering but I only go on a one-day hike usually.
After watching the great comet C/1996 B2 Hyakutake you returned to hunting. Did you change your equipment compared to the 70‘s?
Wide field telescope with an aperture of around 15 cm was considered to be the best in Japan. As far as my equipment goes, I changed my comet-seeker from the home-made 12.5 cm reflector in my boyhood to the 12.5 cm refractor, BORG 125ED, in 1996. As a refractor has no secondary mirror, it is suitable for getting wider field of view. However, the refractor was too expensive to purchase in my teens. In 1996 the price got down and at the same time the performance was improved by the use of ED glass.
Where do you hunt from?
There are some observing sites. In summer I drive to the best observing site with an altitude of 962 m above sea level (a.s.l.). It is a 30-minute drive. Sometimes I comet hunt from behind my house, though the site is moderately light polluted except for the eastern and western sky. I live in a heavy snowfall area and the best site is closed in winter, i.e. from December to April. In winter I use two sites mainly. One is a 15-minute drive with 340 m a.s.l. and another is a 25-minute with 425 m a.s.l. The site with 425 m a.s.l. is better, but light pollution emanating from a ski field deteriorates the sky condition on weekends, because the ski resort opens through the night on weekend. I am forced to select the site with the altitude of 340 m a.s.l. on Saturday, Sunday and national holidays.
Can you describe us your hunting strategy?
The magnitude of newly discovered comets both by amateurs and by professionals is getting fainter, because the performance of CCDs is getting higher. As a visual comet hunter, my counter measure for the trend is the use of larger aperture and/or higher magnification. I employ a 46-cm (18”) Dobsonian and I think the aperture is reasonable. A telescope larger than that, e.g. a 60-cm, is hard to set up and more sensitive to astronomical seeing. The seeing conditions of my observing site is sometimes very bad and the star image swells that looks like Jupiter especially at a low altitude. The larger the aperture becomes, the more sensitive to seeing the telescope is. For those reasons I think the 46-cm is good for me so far.
I have increased the magnification of my comet-seeker from 68x (discovered C/2002 E2 Snyder-Murakami) to 78x (332P Ikeya-Murakami), and now I usually use 97 magnification. I have seldom identified 14th galaxies with the magnification of 68, but many times with that of 97. However, when 'seeing' is poor I am forced to reduce the magnification to 78. I must say 97x is the maximum, because the actual field of view (FOV) is 1 degree with 97x and I do not want to make the FOV narrower to keep the efficiency of comet searching, i.e. typically, I cover 40 degrees vertically and 25 degrees horizontally for a comet hunting session.
Nevertheless, my recent strategy may be defeated by smaller instruments with wider FOV and lower magnification, if a bright comet appears. Actually, 332P was 9th magnitude upon discovery. C/2015 F3 SWAN and C/2015 P3 SWAN were both 11th magnitude and were discoverable with a 20-cm telescope under a dark sky. There is no correct way of comet hunting.
Do you know whether are there other visual hunters using simillar or even bigger scope as you?
Yes. Patrick L. Stonehouse discovered C/1998 H1 (Stonehouse) with his 44-cm, Don Machholz did C/2010 F4 (Machholz) using a 18” Dobsonian, and Vance A. Petriew found 185P (Petriew) with a 20” telescope, though Petriew is not a comet hunter but he discovered the comet accidentally at a star party. Rolf G. Meier made visual comet discoveries in 1970s and 1980s using a 41-cm telescope, i.e.. C/1978 H1 (Meier), C/1979 S1 (Meier) and C/1980 V1 (Meier).
First light of your 18“ Dobson went on in July 2001. Then half year passed and on your 40th birthday you decided to switch from 20 cm telescope to the Dobson for comet hunt. It appeared as a good choice. Can you recall the moment you understand that you finally caught your first comet C/2002 E2 Snyder-Murakami ?
During my comet hunting session on the day, I spotted a diffused comet like object. I thought the object must be a known comet. One reason was that I knew there were some faint comets in the eastern sky. Another was that I actually did not know the ability of my new “comet-seeker”. It was the third time for me to use my 18” telescope for comet hunting and I still did not know the limiting magnitude of the telescope. I presumed my 18” could detect a 13th magnitude comet, and I thought the comet I spotted must be a known one. At a glance the magnitude of the comet was 13th by intuition.
I was very calm, but I thought the comet might be a new one. I positioned the object as precisely as possible, and confirmed the motion. I also noticed a faint tail, and there was no doubt that the object was a comet. Prior to the discovery, I identified two globular clusters, NGC6426 (mag. 11.2) and NGC6535 (10.6). The magnitude of the comet was brighter than NGC6426 and fainter than NGC6535, i.e. the magnitude was 11. However, I had no way to confirm if the comet was new one or not at the site.
I went back home and I switched on my PC. I opened a digital map, MegaStar5, and the display showed the positon of interest. There was no known comet there! It was the moment when I caught a new comet.
4 years passed and you were pretty near to another discovery. Unfortunately David Levy´s new comet C/2006 T61 (Levy) was announced 3 hours and 43 minutes before your observation. Were you very disappointed then?
Not so much. Many comet hunters have ever experienced such situations. At that time I felt I also encountered the “incident”. I have read somewhere that in the 1970s and 1980s when the communication technology was poor, some potential new comets that were reported were lost; it took long time to request observers in the world to confirm the objects. Another story at the era of the Cold War was more irritating. A comet hunter in the Eastern country tried to report his discovery to CBAT but the telegram was not sent to the US. The comet was discovered by a Western hunter and announced.
Your second discovery C/2010 V1 (Ikeya-Murakami) came in 2010 and it was assigned as 332 P/Ikeya-Murakami after its recovery on 31.12. 2015. It was observed at his its return also by Hubble Space Telescope. Unfortunately it split up into 9 fragments. Is it there a chance to observe it in its next return?
Probably it is challenging to recover the comet at the next return. Nonetheless, I think we have a slight chance to observe it, because we still do not know much about characteristics of comets. For example, most astronomers assumed that C/2011 W3 (Lovejoy) would evaporate and disappear at the passage of the perihelion, but it survived and grew up as the great comet.
Perhaps there is no other country in the world where so many devoted people hunted for comets at one time. They were not only hunting, but numerous of them were succesful. What caused that big interest and achievement?
Tsutomu Seki who discovered 6 comets including the great comet C/1965 S1 Ikeya-Seki contributed to it. He is a good writer and published over a dozen of books for comet hunters and general citizens. His books are really page turners. Many people in our country were impressed and stimulated by his publications; some became professional astronomers while others devoted their life to comet hunting. Some publications describe how to comet hunt in detail, e.g. what kind of telescope is suitable for comet searching, how one should sweep the sky, and the statistics of comet discoveries. His books for ordinary citizens tell them to have a goal in their life through his experience on comet hunting in order to make it fruitful. He wrote not only for adults but also for children, and the books have been supplied to school libraries all over Japan. He is also an eloquent speaker. His audience is always drawn to his lecture and motivated by his attractive stories of the starry heavens. I think his wide range of activity on public relations has given birth to comet hunters in Japan. I must say that so many Japanese comet hunters would not exist without Tsutomu Seki’s great dissemination.
Japan was without no doubt the country with highest comet hunters at one time, where tens of them were on field around the same time. Was there a big competition within the Japanese themselves? Do you take others as rivals?
Yes, there still is competition among Japanese, and I take all other Japanese comet hunters as rivals. However, not only Japanese but also comet hunters all over the world compete with each other and are rivals for me. I regard the Pan-STARRS as one of the rivals.
The first Annual Comet Conference was held in 1971 and since then every year. It became a big tradition. You attended it first time in 1977. Have you attended it regularly?
No. I attend the conference mainly when the venue is near my city, though there were some exceptions. I have even chaired the conference twice.
Have they changed during the years?
Certainly. The number of attendees varies in each year. For example, it was 134 in 1977, and 77 last year in 2016. The highest record was 202 in 1987 when B.G.Marsden gave a lecture. The conference consists of the whole meeting, e.g. lectures by guest speakers and oral and poster presentation, and the sectional meetings, e.g. photometry, orbital calculation, comet hunting and physics of comet. The kind of sectional meeting changes every year. In my boyhood the comet hunting was one of the major themes of the conference, but in recent years it is getting minor.
In 2003 and 2004 you published series of 3 articles "Can comet hunters survive?". How did other hunters respond to it?
The motivation of writing the articles was an email from Syogo Utsunomiya, the Japanese comet hunter. He was afraid that we visual comet hunters could not discover a new comet anymore due to robotic surveys. However, he was relieved with my analysis that was posted on my web site. In my memory he was the only comet hunter who responded to my articles in Japan. Other than Utsunomiya, Terry Lovejoy was encouraged to read my articles. Hoshinavi, the Japanese monthly magazine on astronomy interviewed him in 2007. It reads, “The article by Toshimi Taki and Shigeki Murakami, Japan, entitled ‘Can comet hunters survive? (3)’ claims amateurs can still discover a new comet, and they search for the specific method. […] This article gave me much conviction and substantiation that comet hunting using DSLR camera is effective”. I am glad he has succeeded to read our article.
Over the years, you have traveled abroad and had the opportunity to get to know the night sky from other countries as well. On your trip to Hawaii islands you learned about the threat of light pollution. You said that "we need to conserve the dark and transparent sky that diminishes on this planet." Are countries doing enough for it? What is the situation in Japan?
As far as I know few countries try to reduce the light pollution. In Japan, the Ministry of Environment set the guidelines for diminishing light pollution many years ago, but there is no obligation for both individuals and companies to obey it. I feel the sky is getting brighter year by year at my observing site, even though the population in my city and the surrounding areas is decreasing. I think it is partly because the florescent light is replaced with the LED that I think emits stronger beam.
In 2012 you visited Australia. How can you compare few minutes of the total solar eclipse you observed in Cairns and feelings after comet discovery?
Observing the totality is one thing and comet discovery is another. It is true that the totality in Cairns was one of the most impressive astronomical phenomena that I have ever seen. The others were Leonids in 2001, and the great comets, i.e. Hyakutake and Hale-Bopp.
The discovery of a comet is different from observing objects or attractive phenomena in the following two points. Firstly, the solar eclipse is precisely predicted beforehand, while the discovery of new objects is unpredictable. Though a sudden appearance of new objects is also unpredictable and can be impressive, observing it is dissimilar to discovery on the other side. That is to say, secondly, watching the totality, or meteor showers, or the great comets is “passive” action for those who enjoy it, but discovering is “active”.
I must say a discovery is a destiny in a sense that one may never find any object at all through his or her life irrespective of the devotion. Some may spot a new comet accidentally, e.g. in a shot of a photo, and I think it is also fate.
Many comet seekers during last two decades simply gave up, some switched from visual to CCD search. But you are determined to continue your hunt by already proven method, visually. What is your driving force?
I do comet hunting because the starry sky is beautiful. Visual searching is primitive but the natural way to recognize the beauty and to spot something new. Though the Large Synoptic Survey Telescope (LSST), which has more powerful detectability of new objects than PanSTARRS, commences the full survey in 2022, I do not think visual discovery is gone. It is sure the chance of visual discovery becomes rarer than in today when LSST starts to work, but the fact is not important for me. It is great joy for me to be stepped into the loveliness of the night sky via comet hunting activity.
Do you know how many visual hunters are still active in Japan and abroad?
As far as I know Kaoru Ikeya, Syogo Utsunomiya, Masanori Terasako, and Masamitsu Nakamura are active visual comet hunters who have discovered at least one comet in Japan. I know there is an active visual hunter who has yet found a comet. I do not know if there are any active visual comet seekers abroad or not at present.
What is your favorite astronomy related quote?
Minoru Honda’s maxim:
"If you are still content even without a new discovery, continue your search. You may be able to find a new comet."
I knew the saying since my mid teens, but I thought I would never understand the real meaning even if I grow up. After my first comet discovery, however, I see the implication. If a comet hunter is aggressive in searching for many years without discovery, he or she would be discouraged to quit hunting. The comet hunter should not search for a new comet intentionally, but should enjoy stargazing itself to keep searching.
The date and time of the last visual comet discovery is approaching, perhaps it´s already over. At present you are the last visual comet discoverer. Do you mind that there will be another “record holder” of it or you prefer to confirm it by your next discovery?
I hope someone discovers a new comet visually. As I mentioned in the video that was recorded on 2nd October 2015, there were some comets that were discoverable visually in 2015. One of the reasons that they were spotted not by a visual hunter but by SWAN was the decrease in the number of visual comet hunters. I think the chance of visual discovery is on the rise.