©2000 BMAA, Inc
Transient Phenomena, or "What the H### was That"
- by Alan Pasicznyk
It was back in 1993 when Carolyn and Eugene Shoemaker, along with David Levy, first discovered an image of what appeared to Carolyn as a "squashed comet" on a photographic plate of an all-sky survey that they were doing. Moreover, this same comet was later predicted to be on a collision course with the planet Jupiter. After attending a lecture given by David Levy at the Franklin Institute, the only thing that became apparent was that exactly what the effect on Jupiter's atmosphere would be from the collision could be summed up in one word: "Unknown".
It was during this time that I first hit upon the idea of forming a "Transient Astronomical Phenomena Group". Since Astronomy is a real-time hobby, and since we meet monthly, what better opportunity to share information than in a real-time environment? It's more current than waiting for articles to appear in an astronomical magazine. And even with the advent of Internet technology, it's hard to beat sharing and pooling observations and information face to face with seasoned as well as novice amateur astronomers. If you've ever waited for an E-mail response, then you know what I mean. Nevertheless, our club has just recently added a page to our website specifically for the topic ofTransient Phenomena. This page will be updated monthly by a summary of the reports made by club members at the last monthly meeting. Additional ongoing reports and comments by others who access this site can be posted as well.
Since I first formed this new function for our club in 1993, we have had a multitude of transient astronomical events take place, with numerous observations and confirmations reported by our own club members: a supernova in the galaxy M 81 visible in telescopes as small as 4.5" aperture, a nova in Cassiopeia easily visible in binoculars, the unexpected dark spots on the planet Jupiter resulting from the impact of comet Shoemaker-Levy 9 visible in virtually any size telescope, several very dark or even black lunar eclipses in the early 1990's, more recently a dark orange lunar eclipse, an annular solar eclipse visible to club members who travelled to New York state, reports of total solar eclipses from members who travelled to Aruba and later from various locations in Europe, the disappearance of the edge-on rings of Saturn, not to mention the surprise arrival of comet Hyakutake filling the night sky, comet Hale-Bopp visible naked-eye to virtually anyone, and for an extended period of time, several meteor and fireball reports, one fireball report from two members in different locations, the beginning of the transit of Mercury at sunset, and finally a nova in Aquila visible in binoculars. And that's not mentioning the transit of the shadows of the moons of Jupiter, which had been reported, sunspot and auroral sightings and other events which escape my memory. It certainly has been an active decade for Transient Astronomical Phenomena!
In order to form some guidelines, I will outline some of what I am looking for in a report. First of all, the single most important piece of information that needs to be recorded, aside from the nature of the event itself, is the time and date. This point cannot be over-stressed! Even if all you do is jot it down on a of scrap paper, it will prove to be invaluable when discussing the event with other members. Secondly, what type of astronomical equipment did you use to observe the event? Naked eye? A four inch telescope? If so, was it a reflector, a refractor or some other design? Keep in mind that certain instruments are better suited for different types of observations, i.e. planetary versus deep sky. I should also mention here that we will be primarily concerned with observations made with amateur equipment, although important discoveries made by professional means will be considered.
For example, if it were not for the discovery of comet Shoemaker-Levy 9, how else would we know to keep an eye on Jupiter in the months leading up to and during the impact? Finally, the observing conditions should be recorded as they apply to the phenomena. What was the transparency like? Even a broad scale like: excellent/ good/ fair/ poor is better than none at all. How was the seeing? For planetary work, this can make the difference between making and not making an observation. Was the light pollution high in the area of the phenomena, or only elsewhere? Also, any other conditions which may pertain to the phenomena itself should be recorded. Thus "It was real clear when I saw the UFO in the morning after I left the bar", becomes a (highly!) probable early morning sighting of the planet Venus. Incidentally, it is interesting to note that the planet Venus was "attacked" by intercept aircraft during the Second World War more than any other planet, except, of course, the Earth!
This brings up the subject of getting a confirmation made to your observation if possible. I would suggest that every club member employ the "buddy system" for this purpose. The value of having an astronomical counterpart that you know you can call late at night to confirm as well as possibly witness an "important" observation cannot be overvalued. Aside from adding more credence to your report, it will also allow you to weed out any possible false alarms, by forcing you to reconsider what you have seen. For example: Is that really a nova in such and such constellation, or a passing known asteroid. If the suspect "nova" is located along the ecliptic, what about the greater possibility that it is a planet! It is therefore wise to be familiar with the methods of searching for the particular type of phenomena that you are interested in. If you are searching for comets, you must at least be familiar with the Messier list, and the more prominent deep-sky objects, as well as the performance and capability of your own equipment. The "Saturn-like" object that supposedly accompanied comet Hale-Bopp immediately comes to mind. The "object" was the result of a CCD saturation artifact, and nothing more.
Hopefully these few tips and suggestions should help make for accurate as well as informative account of new things observed in the sky. I look forward to your continuing reports at the next meeting. Clear Skies!
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- Alan reports on ‘Transient Phenomena’ at every monthly BMAA General Meeting. [ -ed]
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Observing for March
- by Bernie Kosher
fifty years ago....
Amateur astronomy, and professional for that matter, has come a long way since the late forties and early fifties. While reading back issues of Sky&Telescope, it occurred to me that many of you might enjoy the things that were happening back then.
As far as observing, the standard was the homemade 6" Newtonian with Ramsden or perhaps Huygenain eyepieces. For those who have never used these eyepieces...don't. The field is very small and the image rapidly degrades at the edges. There is serious color off axis and one feels they are looking through a barrel with a curved glass top.
The orthoscopic eyepiece was to be treasured and the better ones sold for $15 dollars compared to $4 or so for the Ramsdens. Achmet’s first Ortho was puchased from Edmunds in 1965 and was a revelation compared to the cheap Ramsdens. I still have it, and though it is scratched and beaten it still performs well.
Star charts were limited to visible stars, unless one could afford the newly released Skalnate-Pleso by Becvar (limiting mag about 7.75). The standard was Nortons, to mag 6.5. The old Bonner-Durschmusterung was extremely expensive if it could be found at all.
No, Virginia, there were no laptop PC's or digital setting circles. No go-to Meade or Celestron. No Schmidt-Cass systems unless homemade. Prior to the war there were less than 50 Schmidt systems of any kind. The Maksutov was in its infancy...later to spawn Questar. An advanced amateur may build a cassegrain or Dall-Kirkham.
Color film basically did not exist and the available b+w were slow and grainy. There were no processor controlled guiders and exposures, hand guided with simple synchronous drives, could run hours. As a comparison - Achmet took some unguided 30 second shots of comet Hale-Bopp and reached 9th magnitude. In color. Developed at a one-hour shop, which also did not exist then.
Sky&Telescope cost $3. For a year's subscription. Captured German v-2 rockets were being used to explore the atmosphere to a height of 150,000 feet, and were used for solar spectra work above the moisture laden lower air.
The heralded 200" scope was being fine tuned, and had been left with the edge 20 millionths of an inch too high to allow sag when at an angle. The mirror cell was found inadequte to compensate for this and the mirror was refigured. Just for the record... the 200" scope set large mirror making back 40 years. It was widely believed that this was the absolute top size attainable.
In a take-off on the famous 'War of the Worlds' radio broadcast several years before in the US, a Peruvian radio show broadcast their version of this without disclaimer. The resulting rioting and exodus was quelched by the Peruvian army after 15 were killed.
Russell W Porter, the man most responsible for amateur scope making in the US to flourish, a Stellafane original and one of the guiding lights in the 200" project passed away.
Red giant stars were thought to be newborn.
Mars still had canals. Pluto was 6400 miles in diameter +/- 10 percent. This was revised three months later by the same author, to 3600 miles + or - 5 percent. Nereid, the second moon of Neptune was discovered. Jupiter had 12 satellites, Saturn nine.
The Large Magellenic Cloud was about 80,000 light years away and the Andromeda Nebula (M31) was about 650,000 light years. Current values seem to be about 175,000 and 2.8 million respectively.
Elements 97 (Berkelium) and 98 (Californium) were synthesized at Berkely.
Tellurium 130 was found to have a half life of 1.5 sextillion years, about 500 billion times the age of the Earth. Isn't that a handy thing to know. How?
A 6" mirror kit (Pyrex no less) was $4.50.
A small column began appearing in S&T's pages, describing things for the amateur to observe. "Deep sky wonders" by Walter Scott Houston became a mainstay for several generations of telescope nuts.
The international billion was equal to one million million while the US billion was 1000 million.
Lunar craters were still thought to be caused by rising bubbles bursting through the partially molten crust of the new formed moon, or by subsequent volcanic action.
Allyn Thompson's "Making your own Telescope' appeared as the bible of the amateur.
The ads in S&T didn't appear until about halfway into the magazine. The lead articles were more important. The letters appeared in the early pages, as did the monthly series by Otto Struve. I learned more amateur level astrophysics in an understandable way through these articles than through any other.
This has been quite a trip down the old lane. I started observing with Brad Miller as a junior high student in the early and mid sixties. By then much had changed and still continues to do so.
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- BMAA member Bernie Kosher (Achmet) provides the monthly ‘Tips’ column. He welcomes input and feedback. [ -ed]
WHAT IS A LUNAR ECLIPSE?
- by Alan Pasicznyk
A lunar eclipse happens when the Earth gets in the way of sunlight that is going to the Moon. Some people incorrectly surmise that any time that a portion of the Moon is dark, that it is due to the Earth blocking light to the Moon. For example, a crescent moon as seen in the evening, is the result of the Sun striking the side of the Moon, and not being able to illuminate the entire face of the Moon that we can see. Conversely, a lunar eclipse can only happen when there is a full moon, because only when the entire side of the Moon facing us is illuminated, is the Earth in the proper location for a lunar eclipse, i.e. the Earth is directly between the Sun and Moon.
This lining up of the Sun, Earth, and Moon takes place about once a month, so you would expect that we would have a lunar eclipse once a month, but this is not the case.
The Earth revolves around the Sun like a speck of dust on a record or CD. But the Moon revolves around the Earth on a plane (think of a loose-leaf reinforcing washer) that is inclined at an angle to that of the Earth and Sun. What this means, is that sometimes the Moon will be too "high" above the record, and sometimes it will be too "low" below the record (of the Earth - Sun system). Only when the Moon is passing through the Earth-Sun plane AND when it happens to be at full moon, can we have a lunar eclipse.
Not all lunar eclipses are the same. Sometimes the Moon is closer to the Earth during an eclipse, and as a result it is farther into the shadow of the Earth. This dark shadow is called the Umbra. When the Moon is farther out, or not perfectly in line with the Earth and Sun, it is only partially eclipsed. This less-darkened shadow is referred to as the Penumbra.
Did you know that by observing a lunar eclipse, you can tell a lot about the Earth's own atmosphere? In the 1960's and 70's lunar eclipses all had a dark orange tint. But in the early 90's the preceding shadow on the Moon was at times nearly completely black! What happened was this: In the late 80's and early 90's several volcanoes exploded (in Mexico and the Philippines), putting an extremely large amount of dust into the Earth's upper atmosphere. Here on Earth, we could see a spectacular orange sky after sunset as a result of all the extra dust. This extra dust in the sky scatters the sunlight, but since blue light scatters the most, which gives us a blue sky, and red or orange light scatters the least, we see all the orange light toward the direction of the Sun at sunset.
As a result of having all of the orange-red light shining toward the Earth's surface and absorbed, none is left to pass around the Earth's shadow and illuminate the eclipsed Moon. Thus the resulting lunar eclipses seen in the early 90's appeared nearly totally black. So if we have a lot of upper atmosphere dust we have a very orange sunset, and a very nearly black lunar eclipse. With less dust, the sunsets are more yellowish in cast, but the lunar eclipses take on a ruddy orange color. The lunar eclipse in January of 2000 was dark orange. So most of the dust in the Earth's upper atmosphere has finally settled out.
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- BMAA member Alan Pasicznyk occassionally contributes articles to the CONSTELLATION. [ -ed]