Comets are my favorite celestial objects. Whenever I hear that a comet has been discovered or recovered, I get a bit antsy. I wait for an ephemeris, wondering how bright it will get and what direction it is headed. I hope for clear nights during the dark of the Moon. When I see a comet, I know that I am observing something that is just passing through and will only grace our skies for a short time. Some comets are visiting the solar system for the first time, others for the first time in thousands or millions of years. Then there are the periodic comets, most of which have been observed and recorded many times before. Each one is different,but they all share a common origin very closely tied to the origin of life on Earth and the shaping of the solar system as we know it.
--from "Comets--3 for the Price of 1", February 1, 1996
When I wrote those words, I had not yet heard of the discovery of C/1996 B2 (Hyakutake). I had just observed three fairly bright comets in one night, and my appetite for observing had been temporarily satisfied. While writing up this account of my observations, I also surmised that "by the next clear, moonless night, there may be another comet or two for me to track down!" I didn't know how right I was, even when I had checked the Comet Observation Home Page and heard of the discovery. The comet hadn't announced itself with much fanfare. It was dim, far to the South, and moving slowly eastward. No orbit had been calculated for it, so I never suspected it was going to make a close approach to Earth. As far as everyone was concerned, C/1995 O1 (Hale-Bopp) was destined to become the next great comet in March 1997. The only interesting point about this new comet was that it was the second comet discovery in five weeks by the same person: Japanese amateur Yuji Hyakutake. This was unusual, but then again Don Machholz discovered three comets during the summer of 1994, so it had been done before.
It took about four days for the news of the comet's impending approach to be widely propagated over the Web. The first forecasts seemed too good to be true: The comet would pass about 9 million miles from Earth, and might be the brightest comet since IRAS-Araki-Alcock came only 3 million miles from Earth in 1983 (a sight I've always read about and regretted missing). It might be even brighter! Still, a lot can happen in two months, especially where comets are concerned. I contented myself with the fact that the comet should at least get bright enough for me to see in binoculars or a telescope.
On the morning of February 16, with the clouds and Moon out of the way, I got my first glimpse of the comet. I observed both Comets Hyakutake; the newest one was smaller, just a touch fainter, but more condensed, with a starlike center. Unlike the other comets I observed that night, it had a definite SHAPE. The coma was positively parabolic, although it had not yet developed a tail.
The comet was still in the southern sky, and I had to be awake at 4:00 a.m. in order to observe it. After two weeks of bad weather and moonlight, I was able to see the comet on March 1. It had definitely grown in brightness, as it was now visible in my little 7x35 binoculars. In a telescope, its coma had spread out, and there was a hint of a tail to the West. The comet still retained its starlike center.
Disappointment is only a factor when an astronomical event catches the public interest and is covered by the mass media. Very few events achieve this distinction; in recent years, the 1993 Perseid meteor shower and the 1994 collision of Comet Shoemaker-Levy 9 with Jupiter sparked considerable public interest. Once news of an event is relayed to millions of people unfamiliar with the sky, it is certain that some disappointment will creep in. In the realm of astronomy, comets and meteor showers share the distinction of being semi-predictable. Past observations and studies invite comparison, but we never really know what an object will look like on a given night until we actually see it. This can be disconcerting to a world accustomed to the regularity of prerecorded television shows. Once the media grabs on to a story, expectations often become inflated. Hyakutake was the main story on the front page of the Oregonian on March 20, under the title "Fire in the Sky". The front page of the next day's Science section might have been more appropriate. "Fire" overstated the appearance of a comet, at least from a location in the city, and the orange color that pervaded the article might have convinced some readers that the comet would be orange. Invariably, some novice observers lampooned the article after glimpsing Hyakutake, saying that the title should have been "Fuzz in the Sky". The graphic accompanying the article was supplied by the Knight-Ridder Tribune, and listed incorrect dates for the closest approaches of the comet to the Earth and Sun. It also claimed that Hyakutake was the "brightest comet of the century", further increasing chances for disappointment.
Fortunately, the overpublicity and the incorrect dates were the only major errors in the Oregonian story. Anyone taking the time to read the whole article would have found a thorough and accurate account. Anyone attending the public star party would be guaranteed a look at the comet if the weather permitted, whether or not the comet lived up to expectations. The article did not shy away from using the term "light pollution", and advised people to get away from the city lights in order to get the best view. Other media sources were not as helpful. According to a few people on the Usenet newsgroup sci.astro.amateur, ABC's "Good Morning America" featured a reporter who claimed to see the comet but actually was looking at (and gave viewers directions to) Venus! As we have become more civilized, we have lost touch with natural events. We have paved the wilderness and washed out the stars with city lights, until they no longer enter human consciousness as they must have many generations ago. Comets no brighter than Hyakutake inspired fear and awe among people who were not sure what they were seeing. They still do, as evidenced by the only two individuals I happened to meet at my rural comet-viewing site. Their first remarks to me were along the lines of: "I don't know what that is, but it sure is something!" From the Portland area, the comet was still something, but the descriptive term "fuzzball" matched the appearance all too well. Only from dark locations was the comet's tail easily visible.
Still, a bright fuzzball in the sky ought to inspire awe. Long ago, people were accustomed to finding their way by the Big Dipper and North Star. A fuzzy patch as bright as any of the stars in the Big Dipper, remaining visible for a week or more, would certainly be noticed. Today, we find our way (when we need to) by looking at the signs on the freeway. With no basis for comparison in the sky, it is hard to see that the comet is special.
I hastily prepared a trip to fairly dark skies, only 30 miles away at Goat Mountain. I saw a lot more than the comet, as I also ran a Messier Marathon, viewing 103 out of a list of 110 bright deep-sky objects. Only one of the Messier objects, M45 (the Pleiades) was brighter than the comet. Some were plainly visible to the naked eye, others could be seen in binoculars, and still others stretched my small telescope to the limit. All had one thing in common: they appeared fuzzy through some instrument. French astronomer Charles Messier was a comet hunter in the mid to late 1700's. When one hunts for comets, one looks for a fuzzball that slowly changes position. Messier noted that certain objects appeared fuzzy like comets, but remained fixed in the sky. So that he and other comet hunters would not be distracted by these objects, Messier catalogued their positions. Although Messier discovered 13 comets in his lifetime, and observed many more, he is remembered for his list of 110 troublesome, nebulous objects.
We now know more about the nature of these objects: They are various star clusters, gaseous nebulae, and galaxies. All are immense compared to a comet or even to our solar system, but from our vantage point we see them as dim smudges.
From this site, I observed the comet rising in the East at 10:06 Local Time. It is a sight I'll never forget. I wasn't even thinking about the comet when I turned my eyes to the horizon, but I saw it just as it was coming up through the trees. It was still a smudge, but how many times have you seen a smudge rise in the night sky? Personally, the view reminded me of the much maligned apparition of Comet Halley in 1986. I followed Halley for many nights in December, 1985 and January, 1986 before it slipped into the sunset. It was barely visible to the naked eye, although toward the end it showed a tail in binoculars. Then, in March, 1986, Halley finally poked its head and tail above the Eastern Horizon just before morning twilight began. Halley looked like a fuzzy star until I turned my binoculars on it and saw a faint tail stretching across the field. In my little 60mm telescope, Halley's head turned into a gaseous mass with a starlike point at the center and streamers of tail shooting out the side. As Hyakutake rose, I could not see any of its tail. As the comet climbed higher in the sky, however, I could see a faint tail about 2 degrees long even with my naked eye. In my telescope, the tail was more subtle, but the coma filled the entire field! I was definitely satisfied with this view of the comet, but what about the so-called "general public"? They had been told that Halley would be difficult to see, yet still I hear people talking about how Halley was an overhyped bust. Hyakutake had the advantage of being better placed in the sky (I suspect most people didn't even try to get up in the dead of morning, as was necessary to view Halley at its best). Still, the comet would have to brighten and grow a nice tail in order to be remembered fondly. It would help if the weather cooperated over the next two weeks, but was that hoping for too much in Portland? Already, the next day was shaping up to be cloudy.
UT - Universal Time (Mean Standard Time at Greenwich Royal Observatory in England), the standard used by astronomers. UT is 8 hours ahead of Pacific Standard Time and 7 hours ahead of Pacific Daylight Time, so 6:53 UT on March 23 is astronomy-speak for 10:53pm PST on March 22.
NAKED EYE LIMIT or Limiting Magnitude - Magnitude of the faintest star that can be seen with the naked eye.
ARCMINUTES and DEGREES - Units of angular distance in the sky, which can be seen as a spherical dome. There are 60 arcminutes in one degree. The size of the Full Moon is about 30 arcminutes or 1/2 degree.
COMA - Head of the comet.
m1 or INTEGRATED COMA MAGNITUDE - Estimate of the total brightness of the coma. Lower or negative magnitudes are brighter. Because the light from the coma is spread out over a large area, a comet will appear fainter than a star with the same total brightness.
CENTRAL CONDENSATION - Structure seen in some comets, usually resembling a star in the very center of the coma. This should not be confused with the solid NUCLEUS of the comet, which is too small to be resolved. m2 is an estimate of the magnitude of the central condensation.
The coma diameter is about 35 arcminutes, strongly condensed but edges suppressed by skyglow. Tail to the West, 1 degree long in 7x35 binoculars. Integrated magnitude of coma: 1.7.
Naked eye limit: magnitude 5.1
The comet has brightened since last night; tail has grown a lot and coma size has increased. Tail Southwest to 2 degrees with naked eye, length over 4 degrees in 7x35 binoculars. Coma diameter is approximately 50 arcminutes. Starlike central condensation of magnitude 4 dominates naked eye impression of comet. The tail is curved with several streamers, and an extension of the coma is suspected to the Northwest. Integrated magnitude of coma: 1.5.
Naked eye limit: magnitude 5.0
Hyakutake is HUGE! Coma diameter is 1.5 degrees in 7x35 binoculars. Six degrees of tail are visible to the naked eye. In binoculars, the main tail extends for 12 degrees, with a northern branch 6 degrees long. Integrated magnitude of coma: 0.3. Magnitude of central condensation is 3.9, as estimated with naked eye.
In a 60mm refractor at 79x, the inner coma appeared to be a very dynamic place. In the immediate vicinity of the central condensation, a jet extended for 3' to the Southwest, in the same direction as the tail. Another, fainter jet was visible on the other side of the condensation. Lots of fine structure was visible ahead of and around the condensation.
Gladstone, OR and points east
Variable sky conditions
Partly cloudy, comet seen through gaps. The coma diameter is greater than 1.5 degrees in 7x35 binoculars. The tail length in binoculars is over 15 degrees. Integrated magnitude of coma: -0.4. I tried to drive out of the city in hopes of seeing more of the tail, but the clouds closed in and interrupted observations.
Goat Mountain, OR
Naked-eye limit: magnitude 6.6
The comet thoroughly dominates the dark sky. I estimate the tail length to be 65° in binoculars and with the naked eye! The coma diameter, after my eyes dark-adapted, appeared to be around 3° . My naked-eye estimate of the total magnitude of the coma was -0.5. The nearly stellar central condensation (magnitude estimated at 3.4, naked eye) still dominates the coma, but not as much in this dark sky. With a 60mm refractor at 36x, the entire field of view is filled with an intense bluish-white light, with the sapphire false nucleus at the center along with the spike of the tailward jet.
At 10:00 UT, here are my impressions of the tail structure in relation to nearby stars (see sketch):
With the head of the comet placed just Southeast of Thuban, the tail extended in front of Alkaid with an initial width of 1.5° . In the vicinity of Alkaid, a faint branch of the tail extended WSW past the star Cor Caroli. The main part of the tail broadened after Cor Caroli, reaching 3° in width. The edges of the main tail touched Alpha Comae Berenicis and the Coma star cluster, reaching a width of 8° at Beta Comae Berenicis. A branch to the South at this point ended near Epsilon Virginis (Vindemiatrix); the width of the tail at Vindemiatrix was 18° including the branch. The tail terminated in the head of Virgo, with a final observed width of 15° near Gamma Virginis (Porrima).
Goat Mountain, OR
Naked eye limit: magnitude 6.7
The comet is just as impressive as last night; the tail length is again around 65° , the coma diameter is nearly 3° , and the total coma magnitude (m1) is still at -0.5. The tail appeared to have more diverse branches tonight.
Here is my account of the tail detail:
First 6-8° is very bright and narrow (~1° ). The tail becomes broader and fainter beginning at the little triangle of 7-8-9 Draconis. In binoculars, the tail has a kinky, streamered appearance from this point to Alioth. The tail is 5° wide at Alioth. Alioth is near the Eastern edge; a branch splits off on the Western edge here, parallel to Gamma UMa- 67UMa. Beta CVn is in the bright Eastern part of the tail, which now has three branches. The total tail width at Beta CVn is 10° . The Westernmost branch that started near Alioth becomes very faint near the Western edge of the Coma Berenices star cluster, but possibly extends on to 93 Leonis. The other two branches go right through the cluster, and become dim South of the cluster. They seemed to terminate in the vicinity of 6 Comae Berenicis.
Naked eye limit around magnitude 4.8 with haze
The comet was easily seen despite moonlight and haze; when the haze cleared, 15° of tail were visible naked eye. The first 6-8° of the tail appeared brighter than on the previous two nights. Coma diameter was limited to 1° by light pollution. The central condensation was very prominent, with an estimated magnitude of 3.0. My estimate of m1 was -0.3, but this was only approximate due to the uneven sky conditions.
Goat Mountain, OR
Naked eye limit around 6.3 between high, thin clouds
m1=+0.3 with both naked eye and 7x35 binoculars
Coma diameter greater than 1 degree
Tail length ~25 degrees
The inner coma area around the still-prominent central condensation was more diffuse, contributing to a "hairy star" appearance and probably accounting for most of the loss in observed brightness. The first 10 degrees of tail were bright, and the next 10 degrees were easily seen with direct vision. The tail was suspected to extend for another 5 degrees. The tail extended in the general direction of Merak (Beta Ursae Majoris). A branch from near the coma extends 4 degrees to the Northeast. The tail is quite narrow, with the total width never exceeding 6 degrees. The comet had lots of staying power in twilight, remaining bright as Mir and the Space Shuttle Atlantis passed 4 degrees below the coma at 12:50 UT (4:50 PST).
Comet was glimpsed only briefly before clouds rolled in. I saw a few degrees of tail with the naked eye, but the Moon really suppressed the comet. I wasn't able to make a good magnitude estimate.
Naked eye limit: magnitude 4.8
m1=+1.0 (estimate with 7x35 binoculars)
m2~3.5 (naked eye estimate)
Coma diameter around 45 arcminutes in 7x35 binoculars
Only about 1 degree of tail was visible to the naked eye; 6 degrees were visible in 7x35 binoculars.
The Rose City Astronomers had planned a star party for the evening of March 23, but at 5:30 p.m. they rescheduled it for the following night because of expected cloudy weather. For a while, it looked like this would prove to be a bad decision, as the skies remained clear around Portland. At around 9 p.m., with the comet visible in the East, I started driving towards my dark-sky site at Goat Mountain. As I left city lights behind, the comet's tail became visible through the car window. Just as quickly as I had exited the city, I entered the clouds. Going further East was useless, and they were closing in from the West as well. I had to be content with occasional glimpses through clear patches. I hadn't seen the comet in its full glory, so I didn't know what I was missing.
Sunday, March 24, did not inspire confidence. Despite forecasts for sunshine, rain and even wet snow pelted the Portland area during the morning. The wait was agonizing, but finally the weather cleared. It looked like this would be a perfect evening for viewing. I made my way over to the star party at Gabriel Park with my trusty little telescope assembled in the back of the car. I planned to leave the party at midnight and head for dark skies, but for now I simply admired the mass of humanity around me. The parking lot was jam-packed at 7:30, telescopes were set up everywhere, and still people kept streaming in. I took a few looks through the various telescopes and binoculars; most were pointed at the comet, a few at the Moon or Venus.
The obligatory demonstration on "how to make a comet", presented by OMSI, was entertaining and engaging, and sparked the interest of the kids. Comet ingredients? How about dry ice, water, molasses (organic material), charcoal, dirt, ammonia, and air? The resulting mass was "pretty grody", according to the young spectators, but you could see gas subliming away into space, forming a tail!
As for the real comet Hyakutake, it was still a fuzzball, sitting right off the handle of the Big Dipper. The first little bit of tail was just barely visible to my eyes, so I figured inexperienced observers would have a hard time seeing it. Binoculars helped a little. The telescopic view of the comet, as fascinating as I found it, proved disconcerting and confusing to the majority of the visitors. When I set up my telescope, I got comments like: "You can almost see it more clearly with your eye." It was difficult for them to comprehend, even when they were told, that only the central portion of the comet was visible in the telescope field. Luckily, there was a bright spike of dust coming out of the center of the comet, visible only in telescopes. Even if people confused this with the much longer and fainter tail that they couldn't see, at least they got something out of the telescopic view. As always, when I turned my telescope on the crescent Moon, nobody was disappointed with the view.
By 10:30, I was getting anxious to see the comet from dark skies. The park simply had too much light pollution around it, and I doubted the tail would be seen even when the Moon set just before midnight. Hearing somebody say: "I waited 17,000 years to see this?" did it for me. I packed up and drove East again, hoping that I wouldn't run into clouds. I didn't. Goat Mountain is at about 3000 feet above sea level, and a dusting of snow covered the roadside trees. A week ago, I had worried about getting stuck in the mud, but now the mud was frozen. I parked and stepped out into a bone-chilling East wind, but my first look at the sky shocked me more than the cold ever would.
The comet's head was still a fuzzball, but a much larger one, and the tail stretched more than a third of the way across the entire sky! Using my car as a windbreak, I lay down and just looked at the spectacle, trying to sketch the tail and trace its entire length and faint branches. The comet was very near its close approach to the Earth (9 million miles), and was probably at its very best, so I just sat back and enjoyed it. Still, I was a bit irritated that the people at Gabriel Park couldn't see what I was seeing. I hoped at least some of them would do as I told them and get out of the city.
At some point in my reverie, a pickup went by my makeshift observing site. I didn't pay much attention; the area is apparently a redneck hangout/shooting range, so the road gets a lot of traffic until well after dark. Since it was now nearly 2 a.m., the flow had stopped. Then, the pickup came back. It went a hundred yards past me, then backed up. The doors opened, and the aroma of Budweiser and cigarette smoke filled the air. I admit that I was mentally planning evasive action, just in case, but these two guys were interested in looking at the comet just like I was. They even turned off the lights on their truck. The conversation went something like this:
Them: "Anybody awake over there?"
Them: "I saw you had a telescope there, and we just had to stop and check this out. Can we take a look?"
I put the telescope on the comet and they took turns looking at it. Like my guests at Gabriel, they weren't sure what they were looking at, and thought the comet would look much better through the telescope. I explained that the telescope had a narrow field of view, so they could only see a little bit of the comet at one time. Then they went on to talk about the comet, saying that they had seen it from the city as just a fuzzball and come up here to get a better look. One remarked: "I don't know what that is, but it sure is SOMETHING!" They asked me whether it was something slowly burning up in our atmosphere, and I informed them that it was 9 million miles away and in orbit around the Sun. I also went into my star party spiel about the various parts of the comet and their dimensions. At about this time, their eyes dark-adapted, and they noticed how far the tail was extending.
"Hey, Bob! Check this out! You can see the tail until clear over there!"
After a few more minutes of watching, they thanked me for giving them "an education" and walked back to the pickup, beers in hand. But I heard them exclaim, ere they drove out of sight:
"Man, that comet up there is BITCHIN'!"
Like I always say, you need to get out into the country to really appreciate the night sky.
The comet was roughly as bright as on the previous night, and most visitors could just make out a tail pointing toward the Big Dipper. We were able to throw some aperture at the comet, with 8-inch and 11-inch Schmidt-Cassegrain telescopes. The tailward dust jet was still big and bright, and we discussed its possible origins. The 8x50 finder scopes mounted on the larger telescopes provided good wide-angle views. Most importantly, the audience was thoroughly interested in astronomy and the comet. I regularly repeated my invocation (now reinforced by experience) to get away from the city if at all possible. I was pleased to hear that students who went to the Oregon Coast over the last few days of Spring Break got excellent views.
I noted that while the comet was "the star of tonight's show" (no astronomy pun intended, but it got a lot of laughs), the Moon and Venus were well-placed for viewing. For much of the night, we had one telescope on the comet, one on Venus, and one on the Moon. As usual, everyone was blown away by the view of the lunar craters, and Venus's half-moon appearance gave the astronomy professors an opportunity to lecture on its phases and their relevance to the Copernican solar system model. When Venus was low in the sky, and the flow of visitors had ebbed, I turned a telescope on the open cluster M36. I explained that this group of stars looked much like a comet through binoculars, and how Charles Messier had catalogued a bunch of fuzzy objects to keep from confusing them with comets. I later put the scope on a galaxy (NGC 2841) to show them what a REAL fuzzball looked like.
At 11:30, we finally closed down. I grabbed some hot chocolate and donuts, and headed back to Goat Mountain. Earlier in the night, the sky had been so-so, with a bit of haze and vapor trails from jets. By 1:00 a.m., none of these problems remained, and the Moon had set. A check of the faintest stars visible revealed that this night was even better than last night. In addition, the wind had died down. The only major change in the comet was its motion northward, the tail still stretched as long. Binoculars revealed many faint stars, seen through the transparent veil of the tail. There was also a "kinky" appearance in the first portion of the tail. I stared and sketched for a couple of hours, lost in what I was seeing.
Tuesday night was completely cloudy at twilight's end. I hoped for a break around moonset, and set my alarm accordingly. Just before retiring, I glanced out my window to see if there were any stars visible. The sky was clear and the comet was right there! I grabbed my binoculars and stepped outside. The comet was near Polaris, and seemed like it should be the real North Star for the night. It had faded very little, although light pollution and moonlight made the tail difficult. The night apparently stayed clear, but I slept through my alarm.
The next night didn't look very good early on, but when I awoke at 2:00 the sky was clear. Fog was threatening from all directions, but I figured I would be above the fog at Goat Mountain. On the way there, my speed was often limited to 20 mph by pure pea soup. As I ascended the steep, half-obstructed forest road, the fog dissipated and was replaced by a slick, white coating on the road. Frozen fog! By the time I reached my site, I was also above the snow line, and walked through several inches of the stuff to a clear viewpoint. I was definitely alone this morning, except for an owl and a few early birds singing of the dawn that was to come.
Although I had gotten above the fog, I was now in the realm of high clouds. I got a quick look at the comet before it nearly vanished. Not until 4:00 did that part of the sky clear again, and still the clouds obstructed some of the tail. Oddly, the tail could often be seen through the clouds. The first part of the tail seemed brighter than before, but the whole tail was less than half as long. The comet's head was less than half as bright, too. The starlike center was bright as ever, but the inner coma surrounding it was ghostly gray rather than the blue-white it had been. This was still a great comet, but the best appeared to be over. I wondered whether it really would brighten again in late April as it neared the Sun, or steadily fade into obscurity.
Twilight brightened the sky, and the birds began to sing in earnest. Still, the comet held on, a testament to its brightness. At 4:49, the combined light of the Space Shuttle Atlantis and the Russian Space Station Mir appeared below Ursa Major. The satellites first faded as they were eclipsed by Earth, then brightened again as they were touched by the rising Sun. The single, starlike point, yellow-orange in binoculars, passed just a couple of finger-widths below the comet. The time had come to leave this winter wonderland. As I crept down the dangerously slippery road, I could see the comet even when the sky was a moderate blue. Then, I entered the fog and descended on civilization.
That would be my last view of the comet from Goat Mountain. The comet was now low in the Northwest sky, too close to the skyglow from Portland. For a week, the Moon would interfere through the entire night. After that, I could see the comet from dark skies again, but only if I went West of the city at the end of evening twilight. The remainder of the week was plagued with cloudy weather. I only got brief glimpses of the comet on Thursday and Friday nights, and none at all on Saturday or Sunday. By the time the sky cleared again on the night of Monday, April 1, the comet had faded to 1/8 its greatest brightness and about 1/8 its largest size. Only a trace of tail was visible to the naked eye in the haze and moonlight. Hyakutake looked almost like it belonged in the rich starfields of the Milky Way, like it might be an unresolved star cluster awaiting its Messier Catalog designation.
Wednesday, April 3 was the night of the Full Moon. The Eastern United States and Western Europe were treated to a total lunar eclipse, with the bonus of an hour of dark sky for comet viewing. On the West Coast, the Moon rose after the eclipse and competed with the comet, but at least the sky was clear in Portland. I started watching the comet at the end of twilight. The comet appeared to be the second-brightest star in Perseus,behind Mirfak. Algol (its name means "The Ghoul") normally holds this title, and normally is of magnitude 2.1, the same as the comet. This evening, however, Algol was in one of its famous eclipses, and was less than 1/3 as bright at magnitude 3.4. As the night progressed, Algol gradually brightened again. The comet appeared more starlike than before;its center even seemed to twinkle a bit. Still, binoculars revealed the tail, stretching up into the crowded starfield around Mirfak.
In the telescope, the coma appeared extremely active, with streamers coming out of the nuclear region and dark, shadowy areas. The comet was showing signs of the Sun's influence. Still, the question remained: Would Hyakutake brighten again?
Near the end of twilight on Thursday, April 4, I got a brief glimpse of the comet without much interference from twilight or the Moon. Still, I was in the city, and there was a bit of haze to go along with the light pollution. As my eyes adapted, I could trace the tail out to about 6 degrees with my naked eye and 10 degrees in binoculars. My magnitude estimate of 1.9 was a little bit brighter than last night, but within the margins of error of my technique. It was at least encouraging to see that Hyakutake had not faded within the last 24 hours.
Friday brought more haze and clouds, but Saturday night (April 6, or April 7 UT) looked like it might be clear. I decided that, whatever the weather, I would go on an observing run to the Coast Range. Again borrowing from the list of sites published by the Rose City Astronomers, I headed West on Highway 26 to Strassel Road. All the way through twilight, the clouds seemed to begetting worse, but when I finally stopped in the darkness the sky was completely clear. Behind me was the obscene glow from Portland. Ahead of me was the comet, sitting just to the right of The Ghoul.
The on-and-off weather pattern decided to end after my trip to Strassel. I caught a couple of quick glimpses the next week in twilight, but for the most part the skies were cloudy. Every day the forecast brought more rain,more clouds, and not a bit of sunshine in the extended outlook. On the evening of April 17 (4:28 UT on April 18, my birthday!), I had just gone to bed when suddenly the sky showed signs of clearing. I grabbed my binoculars and ran out into the middle of the road (the only nearby location with an unobstructed horizon). In about 5 minutes, the comet would be in a cloudless patch. No other stars were visible, but the comet stood in the center of this transitory opening. Its coma was very small,with just a bit of fuzz apparent to the naked eye. Its brightness was hard to judge, but it wasn't much different than before. The tail was very apparent in binoculars, and with the naked eye made the comet appear needle-like. I couldn't see the tail's full extent due to light pollution and clouds, but at least I had seen it again. The comet was hanging in there, waiting for the weather to clear.
During the time of the rains, those with clearer vistas began to speculate that the comet might continue to dim all the way through perihelion. These predictions were in stark contrast to those of a month ago, when the comet seemed ready to challenge Venus in brightness. Still, it is much easier to write an accurate epitaph than it is to make an accurate prediction. On one day,the comet was reported to be "fizzling", on the next gaining in brightness. Only time would tell.
The next evening, I caught the comet in another patch of clear sky. It seemed very dim. In fact, I could barely see it with the naked eye. I estimated its magnitude at 2.9. Fortunately, other observers didn't report this drop in brightness, so the sky around the comet must have been cloudier than the areas containing comparison stars.
Friday, April 19. Another day, same rainy weather. I thought about venturing to Strassel again, but the sky discouraged me. At around 8:45 p.m. Local Time, a little patch of clearing opened up in the Northwest. I saw the thin crescent Moon, with starlike Mercury far to the right. Venus was bright enough to shine through the clouds above these two. I hurried for my binoculars and found a clear horizon. The comet became visible to the naked eye at 21:00 sharp, in very bright twilight. Clearly, it was still bright. Its coma continued to shrink, and its tail could be traced for about 10 degrees despite the light pollution. I observed four wandering objects in this part of the sky (the Moon, Mercury, Venus, and Hyakutake). A Grand Slam! At 9:20, a fifth joined the stage for a brief appearance. This one was the Russian Space Station, Mir. Make that a Golden Grand Slam! Not too bad for an hour's observing with binoculars and the naked eye, especially with 3/4 of the sky completely cloudy.
The Slam marked my last view of Hyakutake. The comet did not brighten as it rounded the sun, and had faded to 3rd magnitude when it was first sighted in the Southern Hemisphere on May 11. Even after the comet's passing, those who saw Hyakutake from dark sky sites on May 25 or 26 are abuzz about the apparition. Countless photographs and drawings from all over the world document the Great Comet of 1996, as Hyakutake deserves to be called. This comet's combination of coma size, coma brightness, and tail length, along with its accessibility to observers, surely render it unique.
As I mentioned in the Preface to this compendium, another exciting comet is heading our way. Discovered on July 22, 1995, C/1995 O1 (Hale-Bopp) is expected to put on a show in early 1997. Will Hale-Bopp be more spectacular than Hyakutake? Only time will tell, although the two comets should have very different apparitions. Unlike Hyakutake, Hale-Bopp will not come anywhere near the Earth. The predictions of great things for Hale-Bopp are based largely on its apparent intrinsic brightness and activity even far from the Sun. As it comes closer to the Sun, Hale-Bopp should become even more active. But, as Hyakutake proved in April, comets don't always become more active as they approach the Sun. Comet Hale-Bopp may well have a significant dust tail, which will be more reflective and easier to see than Hyakutake's tail of ionized gas. On the other hand, orbital geometry dictates that Hale-Bopp's tail will not appear as lengthy as Hyakutake's, and the comet's greater distance from Earth means the coma will be much smaller. Various circumstances conspired to keep me from seeing Comet Hale-Bopp until late May, 1996. When I got out under the dark, morning sky in Southern Oregon and turned my little 'scope onto the comet, what I saw reminded me of Hyakutake in late February or early March.
The time until Hale-Bopp's finest hour would be measured in months rather than weeks, but it was already visible in 7x35 binoculars. It is up there now, awaiting "discovery" by anyone with a little patience and persistence. Together, we will all follow this bit of icy debris on its way to the inner solar system. Hopefully, it will be a bright and easy object in 1997. Like Hyakutake before it, it will be worth a few looks no matter what happens.