The 1980's began as a period of great promise for Australian comet observing. Australia not only had one of the world's most successful comet hunters, it also had an active, nationally organized group of amateur observers, providing a wealth of detailed, high-quality observations of southern comets. For much of the early part of the decade this promise was fulfilled. However by the end of the decade, cracks were starting to appear. Following unfounded criticism of some of the top Australian observers by certain Dutch observers, several, myself included, ceased forwarding observations to the Australian Comet Section, either sending observations direct to US organizations or dropping out of comet observing altogether. Perihelion, the ACS bulletin, also ceased to be a place for detailed analysis of observations, instead becoming a forum for the publisher's speculation. Thus, what started with great promise, had unfortunately dwindled badly be the end of the decade.
The star of the 1980's was, of course, the return of comet Halley. However there were many other highlights of the period. An ever increasing rate of comet discoveries, one of the closest approaches of a comet to the Earth for many years, numerous periodic comets well placed for viewing, and the view of a naked eye comet in the same telescope field as a naked eye nebula and a naked eye supernova!
On a personal note, I spent much of the decade undertaking visual observation of comets. In the early 1980's I sold the 5" refractor that I used extensively for photography, to raise funds for a 16" dobsonian, in the process becoming the first person in Western Australia to own a large dobsonian. At the time, a 16" telescope was considered HUGE, and certainly the view through a large telescope like that, under very dark skies, is something that has to be experienced to understand. It was not until after comet Halley that I was able to repurchase the 5" and get back into regular photography of comets.
One of the first comets discovered during the 1980's that I observed, was not a spectacular sight but none-the-less a very interesting comet. Comet Bowell was discovered by Ted Bowell of the Lowell Observatory early in 1980. Although never brighter than 10.9, and not having a visible tail, comet Bowell was interesting in that it had a hyperbolic orbit, indicating that it would never return to the Sun again. Also, it had very a large perihelion distance and would not reach perihelion until 1982. It was not until 1982 that the comet finally began to show evidence of gas in its coma! Finally, although peaking in brightness in February 1982, the comet showed considerable fluctuations in brightness as it moved away from the Sun and faded. My final observation was in late August, when the comet was around magnitude 12.5
Before comet Bowell became bright enough to observe visually, there were 2 periodic comets and one new comet that I managed to observe in late 1980/early 1981. These were comet Stephan-Oterma 1980g, and comet Tuttle 1980h.
My first observation of comet Stephan-Oterma was on November 4 when it was a small, moderately condensed object of magnitude 9.7. From there it brightened steadily until it reached magnitude 8.7 on November 26. My final observation was on January 15, 1981, when it was magnitude 9.9. At no time was any tail noticed.
I first observed comet Tuttle on November 11, when it appeared at magnitude 8.8 and fairly diffuse. It appeared at its brightest on December 6, when I observed it at magnitude 7.7. The coma was 7' across and diffuse, but no tail was observed. My final observation was on February 4, 1981, when the comet was still quite diffuse and magnitude 9.7.
Bill Bradfield discovered his 11th comet on December 17, 1980. Comer Bradfield 1980t was interesting even though it was always close to the Sun as it flared and fragmented. I observed it on several occassions during late December/early January as a 5th magnitude object with a tail of up to 2.5 degrees.
1981 was a very lean year for comet observing and it was not until June 1982 that the drought of bright comets was finally broken with the discovery of comet Austin 1982g. Before that however, there were 2 comets worth mentioning. On February 5, 1982, Siding Spring astronomer M. Hartley discovered 2 comets on the same photographic plate. It was later shown that these were fragments of the lost comet Du Toit 2, observed only in 1945. Computations by Sekanina indicated that the comet broke apart in 1976. Despite many attempts during March and April with a 10" telescope, the comet was never visible to the eye. The other comet was a favourable return of comet Grigg-Skjellerup 1902II. Unfortunately, although the return of the comet was favourable, the weather wasn't! Thus, although the comet was easily visible in a 6" telescope, very few observations were possible.
Discovered by New Zealander R. Austin on June 18, put on a fine display during late July and early August, when it was an easy naked-eye object with a 2 degree naked-eye tail.
The best view for southern hemisphere observers was on August 2, when the comet was magnitude 5.2 and had a 1.9 degree tail. After this, increasing sky brightness due to the moon and the comet's increasing northerly declination made the comet increasingly difficult to observe. My final observation was made on August 6, when the comet was magnitude 4.3, but deep in the twilight, with only 1 degree of tail visible in a 10" telescope.
Following the disappearance of comet Austin, southern hemisphere observers had a few weeks to prepare for an expected busy time of returning periodic comets. The first of these was comet D'Arrest 1982e. Although the 1982 return of comet D'Arrest was not as favourable as that of 1976, it was still very favourable and the comet became very easily visible in binoculars.
My first observation was on October 7, when the comet appeared as a very diffuse object of magnitude 8.5. The comet peaked at magnitude 8.4 about a week later and then started to fade. However on November 7, the comet was noticeably brighter than my previous observation of October 28. Clearly the comet had had some sort of minor flare. Although R. Bouma of the Dutch Comet Section subsequently made quite rediculous and outlandish comments in his denial of this, the reality of the observations was confirmed independently by other observers. Unfortunately, some people will go to any length to deny what they choose not to believe.
After this date, the comet faded steadily, with my final successful observation being on January 4, 1983, when the comet was just visible in a 10" telescope as a diffuse object of magnitude 11.3. At no stage was any tail visible.
Even as comet D'Arrest was fading from view, the next returning periodic comet, Churymov-Gerasimenko, came into view. My earliest observation that I have still have records for was on December 12, 1982, when the comet was around its peak brightness of 9.8. From then, the comet faded steadily until my final observation on February 18, 1983, when the comet was a very faint object of magnitude 11.9. During December and January, the comet displayed a short, fan-shaped tail which reached a maximum length of 4' during late January.
Following the disappearance of comet Churymov-Gerasimenko, there was a pause of about 3 months and then the dam burst, with a one stage 6 comets being bright enough to observe with a 6" telescope!
The first of these was the periodic comet Temple 1, making a favourable return for southern hemisphere observers.
My first observation was on April 11, when the comet appeared as a small and very diffuse object of magnitude 11.4. From then, the comet brightened steadily until early June, when it peaked at magnitude 9.5. After then the comet faded, until my final observation on October 1, when with a 16" telescope, it appeared as a very faint, and very diffuse object of magnitude 12.8. Between May 15 and June 14, a faint , broad tail was observed, with a maximum length of 4'. An interesting sight was presented on May 30. On that night the comet passed very close the the 13th magnitude galaxy NGC 4591. It was an interesting sight, however the tail passed directly over the galaxy, making it impossible to measure!
At the same time as comet Temple 1 was visible, so also was the periodic comet Kopff. My first observation was on April 11, when the comet was at magnitude 12.0 and very diffuse. From then the comet brightened steadily until it reached magnitude 7.8 on July 14. As the comet brightened, the coma grew in size, reaching a peak diameter of 9', also on July 14. At this time the comet displayed a well condensed coma which also had very faint outer regions, making magnitude estimates very difficult. On May 17, a faint tail was observable, and throughout much of late May and June 2 narrow tails were clearly visible, and during early June, numerous streamers were visible within the tails. By July, the tails had merged into one, with the greatest length observed being 40' on July 4. My final successful observation was on November 8, when the comet was a very faint diffuse object of magnitude 12.0.
Another periodic comet I observed at this time was Pons-Winnecke 1983b. Early into 1983, it had been predicted that it should reach magnitude 12 during May, 1983. This prediction was duly borne out when the comet reached a peak magnitude of 12.1 on May 19.
At the beginning of May came the announcement of a new comet discovery, IRAS-Araki-Alcock. The announcement also made mention that the comet would pass within 0.03AU of the Earth, or about 4.5 million kilometres! The closest cometary approach to the Earth since comet Lexell in 1770!
For those of us in the southern hemisphere, the comet came bursting out of the northern sky, heading south at 1.5 degrees an hour! At magnitude 4.5, the comet was an easy naked eye object and displayed a very diffuse coma over 0.5 degrees in diameter! Reports from the northern hemisphere indicated that the comet peaked at magnitude 1.5 with a 3.5 degree coma!!! The motion was easily visible after only a few minutes. Until that time, it was the fastest natural object I had seen moving in the sky. It was an amazing sight to watch.
After passing the Earth and then perihelion, the comet faded steadily, with my final observation being on July 4, when it was a very diffuse and difficult object of magnitude 10.9.
Hardly had comet IRAS-Araki-Alcock begun to recede back into the dim reaches of the solar system, when another bulletin arrived announcing the soon arrival of another near-Earth comet! The second in only 5 weeks! However, comet Sugano-Saigusa-Fujikawa was no IRAS-Araki-Alcock. If fact it was one of the most intrinsically faint comets in history! Although it passed within 0.1AU of the Earth and reached a peak magnitude of 6.5, the light was spread out over 0.5 degrees and there was no central condensation at all. In the telescope, the comet appeared simply as a ghostly mist drifting across the sky.
The bombardment of comets continued through July and August of 1983. First there was the periodic comet Clark 1983w. It was visible between late July and late September, fading from magnitude 11.2 to 12.9.
At the same time, comet Temple 2 was visible. This comet reached a peak magnitude of 9.6 during mid-August and early September. On September 4, a short, faint tail could be seen. The comet finally faded from view in early November, with my final observation being on November 8, when the comet was a very faint and diffuse object of magnitude 11.6.
Also during August came the announcement of the discovery of another new comet, Cernis 1983l. This comet made a fine sight in the telescope during October 1983, when it reached a peak brightness of 9.6 and displayed a 0.75 degree tail. My final observation of this comet was on January 8, by which time it had faded to magnitude 11.7.
In the same bulletin as the announcement of the discovery of comet Cernis, was the announcement of another discovery with the IRAS orbiting observatory. Comet IRAS 1983j was visible during August and September as a small, diffuse object around 11th magnitude.
The flood of comets continued during December with the discovery of comet Shoemaker 1983p. Again, a small and diffuse object, comet Shoemaker peaked in brightness at magnitude 11.3 in early October and my final observation came on November 26, when the comet had faded to magnitude 12.8.
In the end, 1983 was an incredibly busy year for Australian comet observers with up to 7 comets being visible at any one time. It also set a new record for the number of comet discoveries/recoveries in a calender year, 22. If this does not seem many these days, remember this was the dim, dark past of no CCD's and no LINEAR!!!!
Just after comet Bradfield faded from view, Meier discovered his second comet. However this comet remained too far north to be satisfactorily observed from the southern hemisphere, and it remained below magnitude 11.
1984 started with the discovery of a comet on January 7 by Bill Bradfield. Never a prominent object, comet Bradfield quickly faded from view.
As comet Bradfield faded out, attention was turned towards the periodic comet Crommelin 1983n. The importance of this comet was in that it was to be used as a "dry run" for observation techniques by the International Halley Watch in preparation for comet Halley. The comet peaked at around magnitude 7.4 and made a fine sight in the telescope. However, from a personal standpoint, the best of the comet coincided with a period of cloudy weather followed by a change in dwelling. As a result, I only managed to observe the comet on 5 occasions.
Following the disappearance of comet Crommelin, there was a break of several months until July when Rod Austin discovered his second comet, Austin 1984i. The comet put on a fine show during late July and August as it raced towards perihelion, reaching a peak brightness of magnitude 5.5 and being faintly visible to the naked eye. It also displayed a very nice tail almost 1 degree long.
Even as comet Austin was disappearing, came the news of another discovery, comet Takamizawa. This comet was discovered as it underwent an outburst in brightness. The comet faded as quickly as it appeared and I only managed 2 observations in late August when it was magnitude 10.1 and had a short and very faint tail. At the same time I also managed one successful observation of the periodic comet Neujmin 1 1984c. At magnitude 13.1, the comet was the most difficult I had yet managed to successfully observe. A week later nothing of the comet was visible.
Takamizawa and Neujmin were the last comets of 1984 that I observed. The next comet I observed was comet Shoemaker 1984f. I observed this comet on 5 occasions during March and April 1985, as it slowly brightened from magnitude 11.9 to 10.8.
The next comet I observed was a discovery by Don Macholtz. Heading to within 0.1AU of the sun, this comet was expected to get very bright, however at the time it would be very close to the Sun and unlikely to be visible. I managed to observe it twice in June when it was around magnitude 6 and displaying a 0.5 degree tail. Unfortunately after these 2 observations, the winter weather set in and no further observations were possible.
By now the excitement was building for the "Big One", comet Halley! The big question we were all wondering was, when would our first observation be? For me, this came on July 29, when it appeared as an extremely faint object of around magnitude 13. This was the first visual sighting of the comet from Australia, and once again showed the benefit of the 16" telescope. Unfortunately not long after this, I was forced to sell the 16", something I have always regretted having to do. However it did eventually enable my to purchase back my old 5" f/5 refractor and get back into photographing comets. A more detailed look at comet Halley can be found here. Comet Halley 1982 i
Although much of the attention was focused on comet Halley as it brightened, there were several other comets visible during the last few months of 1985. One of these was the periodic comet Giacobini-Zinner. Although not particularly well placed for southern hemisphere observers, I managed to observe the comet on a number of occasions between September and November 1985. My first observation was on September 24, when the comet was magnitude 9.4 and displayed a 12' tail. From there it faded steadily until my final observation on November 16 when it was fainter than magnitude 11.5.
A bright comet that was also visible at this time was comet Hartley-Good 1985l. Although heading rapidly north and closer to the Sun, I managed to observe it several times between September and November. Initally it was around magnitude 9.2, but it brightened quickly until when I lost it in the twilight in early November it was around magnitude 7.6. At no time did I observe any tail.
Also at this time I was able to secure several more observations of comet Shoemaker 1984f following its reappearance from conjunction with the Sun. These observations showed that the comet was magnitude 11.3 and fading slowly. There was also a new comet, Thiele 1985m. However this comet was poorly placed for southern observers and I only managed one observation, on November 9, when it was magnitude 9.1 with a 4' coma. Finally I managed to make several observations of the periodic comet Boethin 1985n and one of comet Ciffreo 1985p. Although comet Ciffreo faded quickly, comet Boethin reached magnitude 9 early in 1986. A lot of comets to observe while comet Halley had brightened to naked-eye visibility!
While Halley put on its great show during the first half of 1986, things were fairly quiet regarding other observable comets. However, once comet Halley had disappeared into the twilight in July, more observable comets appeared.
The first of these was comet Wilson 1986l. This comet made a fine sight during early 1987 and a more detailed discussion is here. Other comets visible in late 1986 were comet Sorrells 1986n and comet Churyumov-Solodovnikov 1986i. While comet Sorrells reached magnitude 10.3 during early December, comet Churyumov-Solodovnikov remained below magnitude 11.5, although its visibility was enhanced by being well condensed.
1987 proved to be a very busy year for comet observers. At one stage there was over a dozen comets visible in a 12" telescope! It was also the first year in which all the letters of the alphabet were used in designating comets discovered/recovered for that year. With ever more comets being discovered, it was eventually decided to drop the use of letters and switch to a system similar to that for asteroids. To add to the excitement of that year, (at least for southern hemisphere observers!) February saw the first naked-eye supernove since 1604! Supernova 1987A was situated in the Large Magellanic Cloud, not far from the naked-eye nebula, 30 Doradus. When the naked-eye comet Wilson joined the area in May, the sight was one of the rarest ever! Some photographs and discussion of the supernova can be found here.
The first comet I observed in 1987 was comet Terasako 1987d. Although around magnitude 7 when discovered on January 24 and displaying a very nice tail, This comet faded very rapidly and was never very far from the Sun. On a 15 minute photograph on February 28, although showing stars to magnitude 14 and 13th magnitude galaxies, no sign of the comet could be seen.
Another comet, discovered a few days earlier, put on a very nice display during April and May. This was comet Nishikawa-Takamizawa-Tago 1987c. I first observed it in the dawn twilight on April 5. At that stage it was magnitude 6.9 and displayed a fine tail. Over the next few weeks the comet climbed higher in the sky and became better placed for viewing. One of the best views was on April 12, when the comet appeared to be around magnitude 6.6 and displayed a 45' tail. The comet was slightly brighter at the beginning of May, however the tail was fading and not so long as it pointed more away from the Earth. The comet finally faded from view around the end of June.
June and July brought along their usual winter storms and rain, however one night of comet observing was possible on July 25. On that night 4 comets were visible. The first of these was comet Sorrells, reappearing in the morning sky after conjunction with the Sun. At magnitude 11.7, this comet was faint, but not difficult in a 12" telescope. The second comet was Klemola 1987i. This was an exceedingly difficult observation. The comet was only visible with averted vision, and then not continuously. It was impossible to do a precise magnitude estimate, but it appeared to be around 13.5 or slightly fainter. Over the next few weeks comet Klemola brightened a little, reaching a maximum brightness of 12.6 on September 2, before fading from view on November 12 at again below 13.5.
The third comet of the night was also very faint and difficult. Periodic comet Howell 1987h, was making its first return since its discovery. The expected brightness of the comet was in the 16th magnitude range, but this was very uncertain and so observations were requested. I observed it this night as a difficult object of magnitude 12.9 with a 2' coma. This proved to be my only successful observation of this comet.
The final comet of the night was also extremely faint and difficult. Although it was expected to become quite bright. This was the periodic comet Borrelly 1987p. On this night it was essentially starlike and magnitude 13.7. After this night, it brightened steadily, reaching magnitude 8.8 by mid-October and finally peaking at 7.5 at the start of December. During November and early December, the coma became very large as the comet passed the Earth, reaching 10' on December 1. It also showed a strong central condensation that made magnitude estimates difficult. On December 15, a short, faint tail was noticed. The comet finally disappeared into the northern sky with my final observation being on January 19, 1988, when the comet was still magnitude 8.6.
On July 26, yet another comet was added to the list. This was the night of my first observation of the 1987 return of comet Encke. On this night the comet was magnitude 7.6 with a small, very well condensed coma. On August 2, the view was similar, except that the comat had faded to magnitude 7.9. On August 13 however, I measured the coma as 5' and it was quite diffuse. Therefore it is likely that on the earlier dates I was only observing the inner portion of the coma. This comet continued to fade quickly, with my final successful observation coming on August 26, when it was a very difficult, diffuse object of magnitude 10.3.
The rain of comets continued during August of 1987 with the discovery of comet Bradfield 1987s and comet Rudenko 1987u. Comet Bradfield was discovered on August 11, with my first observation being on August 13, when the comet was magnitude 9.4, moderately condensed and with a short, faint tail. From then the comet brightened steadily, finally becoming visible to the naked eye in early November, despite being very low in the north-western sky. The coma became quite large and very well condensed, reaching 7' during much of October. The tail remained quite broad and reached a maximum visual length of 2.25 degrees. During early November, several streamers were visible in the tail. After peaking at magnitude 5.3 in early November, the comet began to fade, with my final observation being on February 13 when the comet was magnitude 9.4.
Yet another discovery of a bright comet came on August 21, witht he discovery of comet Rudenko. I first attempted to locate it on August 26, however it was very badly placed for southern hemisphere observers before perihelion, and I had to wait until October 24 for my first view. On that night it was deep in the dawn twilight, but still an easy object of magnitude 7.3. The comet faded steadily and the coma grew quite large and diffuse, reaching 7' on December 1.
Another bright and interesting discovery came on October 20 when Siding Spring astronomer Rob McNaught discovered a comet, 1987b1. My first observation was on October 21 when the comet was magnitude 8.4 with a well condensed coma and a tail 0.4 degrees long. Although brightening quickly, the comet was also rapidly approaching the Sun and was soon lost in its glare. My final observation was on November 12, when the comet was magnitude 7.4.
In addition to all of these bright comets, there were several faint periodic comet visible during October and November of 1987. Some of these were comets Schwassmann-Wachmann 1, Schwassmann-Wachmann 2, and Brooks 2 1987m. In total, at the begining of November there were no less than 10 comets that might be visible in a 12" telescope! With this many around, I contacted my friend James Athanasou and invited him to join me in an effort to see how many comets we could observe in one night. An account of our effeorts was published in "Astronomy" magaziene in June 1989. In short, we managed to observe 8 comets altogether. The ones that we missed were comet Levy 1987y1 and comet Schwassmann-Wachmann 1.
Yet another comet was added to the list on November 22, when comet Ichimura 1987d1 was discovered. Although there were hopes of a bright display for early January, these hopes did not eventuate. My first observation was on November 23 when the comet was magnitude 8.7, with a large (10') and diffuse coma. The comet brightened steadily as it approached the sun, and the coma became very large, reaching 18' on November 25. On December 15, which was my last observation, the small central condensation was disappearing and a short, faint tail was visible. Also the coma was becoming elongated in the direction of the tail. The magnitude was 7.3, but this was well below expectations. In the end, it became clear that the comet was disintergrating.
The final comet of 1987 that I observed was comet Furuyanma 1987f1. Discovered on November 23, this comet was never particularly prominent. My first observation was on November 25, when it appeared as a small, moderately diffuse object of magnitude 10.4. The comet brightened slightly as it drifted past the Earth, and my final observation was on February 13, 1988 when the comet was magnitude 9.8 with a 6', moderately condensed coma. Unfortunately, not long after this I commenced university studies, which considerably curtailed my comet observations.
1987 was my busiest year ever for comets with 18 being visible at some stage during the year. Add to that supernova 1987A, and it was quite a year! In contrast, 1988 was to be a fairly quiet year although it started off quite busy with a number of comets from 1987 still visible and the discovery of comet Liller 1988a on January 11. My first observation of comet Liller was on January 14 when it was magnitude 9.2 with a 4' coma that was well consensed. Unfortunately I only had time for 2 more observations before it disappeared into the twilight and became a northern hemisphere object only.
After comet Liller, things were very quiet until the end of July, when the periodic comet Temple 2 became visible. My first successful observation was on July 31, when the comet was an easy 11.0 magnitude object with a moderately diffuse coma 6' across. The comet brightened steadily until October 5, when it reached magnitude 8.5, but with a very diffuse 10' coma. After this, the comet faded quickly, with my final observation being on November 28 when the comet was magnitude 11.0.
On August 6, Don Macholtz discovered another comet, 1988j. This comet passed within 0.2AU of the Sun and was probably destroyed. I only managed one observation of this comet, on August 20, when it was magnitude 7.1 with a 7', moderately condensed coma and a 10' tail. After this date, the comet rapidly plunged into the dawn twilight and was lost.
1989 started off like so many years with another discovery by Bill Bradfield, comet Bradfield 1989c.
Another comet I observed, was the periodic comet Temple 1 1987e1. This comet was making a very unfavourable return, however I managed one observation on February 11 when it was a faint and difficult object of magnitude 11.7 with a 5' diameter, diffuse coma.
The first really interesting comet of the year was the periodic comet Borsen-Metcalf 1989n. This "Halley-type" comet with a period of a little over 70 years, was making a favourable return in 1989 and was expected to reach naked-eye visibility. Unfortunately for those of us in the southern hemisphere, it was almost exclusively a northern hemisphere object. That, combined with poor weather and university exams almost totally precluded my observations of this interesting comet.
The same was true for another bright comet, Aaseth-Brewington 1989a1. Although this comet became quite bright and was located well south, it remained very close to the Sun and a difficult object to observe.
A comet that I was able to obtain a good series of observations for was comet Okazaki-Levy-Rudenko 1989r. Discovered on August 24, this comet was well placed for southern observers and made a fine sight in the dawn twilight of late November/early December. The earliest I was able to observe the comet was on November 28, when it was a naked eye object of magnitude 5.5 with a well condensed coma and a 1 degree tail. The comet peaked in brightness on November 30 at magnitude 5.4. The longest tail I observed was on December 4, when the tail reached 1.75 degrees. During early December, the comet started to fade quickly. It also began to become very diffuse. My final observation was on January 3, 1990, when the comet was magnitude 8.1, very diffuse and with a short, faint tail. Interestingly, only 2 days later, Andrew Pearce reported the magnitude to be 10, and only a week later the comet could not be found. Apparently, the comet completely disintergrated during mid January!
The final comet of the 1980's was discovered by New Zealander Rod Austin on December 6. Comet Austin 1989c1 put on a fine display during the first half of 1990, becoming visible to the naked eye and displaying 2 tails, the longest of which reached over 3 degrees.