Click on thumbnail above for larger picture.
This was taken from Baleshare, North Uist, Western Isles, Scotland (looking NE towards Clachan over Mary and Uisdean Mathesons' house) at 57deg 31'N 07deg 21'W .
Note the two differently coloured tails (more on this below).
Date was 8th March 1997 (nearly a year after I had viewed Comet Hyakutake). Exposure was 90 seconds onto Kodak Ultra Gold 400 using an Olympus OM-10 35mm SLR (tripod mounted) on B-lock. Time was 0209 hrs U.T. (+/- 2mins.)
Now that I've had a chance to process and interpret the data I have come across some startling data (well, startling to me).
I was somewhat surprised at the objects that can be captured with my limited equipment. If one looks above the comets' tail (slightly to the right) one can just make out loose conglomerate of stars. This I have identified as the open star clusters NGC 884 and NGC 869 (The Sword Handle in Perseus). They are about 7000 light years away and lie in the direction of the outer arm of our galaxy, the Perseus Arm. The stars making up the cluster are young by astronomical standards, a mere few million years old.
Positioned between the constellations of Cassiopeia and Perseus they are visible to the naked eye. Through binoculars they make an excellent target for amateur astronomers.
This processed and enlarged section of the main photo does not reveal a wealth of detail but I was delighted to pick it up on emulsion and manage to identify it.
Click on thumbnail above for larger picture.
The lesson I have learned is to log every relevant detail when photographing.
The details I had noted down served me well (a few years on) when I started looking at the celestial configuration at the exact time I took the photos. Again, basic kit was all that is required. I used a copy of Redshift v2.0 which I picked up for free on a computer magazine cover. It is not the most sophisticated astronomical software around (nor the most basic) but it was the right tool for the job.
This next enlarged section of the main photograph shows, what I interpret as, an emission nebula (a huge cloud of gas, heated by nearby new stars).
Click on thumbnail above for larger picture.
Possibly the object is IC1795.
I am currently trying to
Watch this space.
Comets - more information
The principal parts of active comets are (in decreasing size) the tails, hydrogen cloud, coma, and nucleus, which are discussed individually below. All evidence available at present indicates that the central body (the ultimate source of all cometary phenomena) is a lump of snow and dust with a typical dimension of roughly 1 km. The ability of this "dirty snowball" to interact with solar radiation and the solar wind to produce features of up to 1 AU long is remarkable indeed.
Tails. Photographs of comets usually show two distinct kinds of tail (see my first photo on this page!): one containing dust and the other plasma (ions and electrons). The dust tail appears yellow because the light reaching us from it is reflected sunlight. The plasma tail looks blue because radiation emitted by fluorescing ions of carbon monoxide within the tail peaks at about 4200 angstroms. Dust and plasma tails can be found alone or together in a given comet. You can compare this by looking at my shots of Comet Hale-Bopp (above) and my other shots of Comet Hyakutake.
Usually observed as sweeping arcs, dust tails typically have a homogeneous appearance and lengths ranging million km to perhaps 10 times that. The component particles are usually about 1 micron across (the size of smoke particles). Their composition is discussed below in the section on the coma. Plasma tails are usually straight, contain a great deal of fine structure, and attain lengths roughly 10 times that of their dusty siblings - up to 100 million km. The plasma races outward almost directly away from the Sun, lagging the true antisolar direction by a few degrees in the sense opposite the comet's motion. Locally the plasma becomes concentrated into thin bundles called rays or streamers. Such ubiquitous details provide convincing evidence that a magnetic field threads the tail's entire length. Consisting of a dense, cold mixture of electrons and molecular ions, the plasma-tail streamers seem to be rooted in a limited zone on the Sun- facing side of the nucleus. Their turning and lengthening provide a good hint as to the origin of the magnetic field.
The insitu measurements provided by spacecraft have removed any lingering doubt concerning the importance of the magnetic field in cometary phenomena. The fields' orientations are what we would expect if solar-wind field lines were draped over the comet's ionosphere. The visible tail corresponds to the region where fields of opposite polarity come together, and along this boundary a current sheer forms. Spacecraft measurements also indicate the existence of a bowshock within the plasma on the sunward side of both comets. Finally, the disturbance that comets cause in the solar wind extends to large distances, as evidenced by the detection of plasma waves and energetic particles.
Hydrogen cloud. In 1970, observations made above the atmosphere at the Lyman-alpha wavelength of 1216 angstroms (deep in the ultraviolet) indicated that comets were surrounded by huge clouds of hydrogen. Similar clouds have been observed accompanying several other comets and span many million kilometres, making them substantially larger than the Sun. Astronomers have used these observations to estimate the production rate of hydrogen for several bright comets approaching the Sun. By the time they cross the Earth's orbit, these objects were producing more than 1029 hydrogen atoms per second! This escaping material cannot originate directly from the icy nucleus because the cloud's observed outflow speed is roughly 8 km per second, about 10 times faster than predicted for material simply sublimating (evaporating) from the nucleus' surface. Instead, most of this hydrogen probably comes from the dissociation of the hydroxyl radical, OH, by sunlight.
Coma. This spherical envelope of gas and dust surrounds the nucleus, extending from 100,000 to 1 million km from it and flowing away at an average speed of 0.5km to 1.0km per second. It is the outflow of coma gas that drags dust particles away from the nucleus. Comas usually do not appear until comets come to within about 3 AU of the Sun.
Nucleus. Until the advent of space missions, we had no photograph of a cometary nucleus - only strong circumstantial evidence had implied the existence of a source of all cometary gas and dust. Spacecraft have now supplied us with a large volume of data on comets, but only one nucleus has been examined to date at close range
There are some ongoing cometary exploration missions to keep an eye on.
It is called STARDUST and is a Discovery mission (like the highly successful Mars Pathfinder). Stardust's objectives are to gather particles flying off the nucleus of Comet Wild-2 and return them to Earth for scientific analysis, and to collect and return samples of interstellar dust flowing through our solar system. Stardust is the first spacecraft ever launched on a mission to bring back material from beyond the Moon. It is also the first U.S. mission to a comet. Stardust's sample return capsule is due to parachute into Earth's atmosphere and land on the U.S. military's Utah Test and Training Range near Salt Lake City on January 15, 2006. It was launched in February 1999.
NASA's CONTOUR Mission Readies for Summer 2002 Launch
Capping nearly two years of detailed development and assembly, engineers at The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, are putting the last touches on the CONTOUR spacecraft, which will provide the closest and most detailed look ever into the icy heart of a comet.
Slated to launch July 1, 2002, CONTOUR (Comet Nucleus Tour) will encounter at least two diverse comets as they zip through the inner solar system. From as close as 100 miles (160 kilometers) away, the spacecraft will snap high-resolution photos of the comet nucleus, map the types of rock and ice on the nucleus, and analyze the composition of the surrounding gas and dust. CONTOUR's targets include comet Encke in November 2003 and Schwassmann-Wachmann 3 in June 2006 - though the mission team can send the spacecraft to an as-yet undiscovered comet should such a valuable opportunity arise.
The second comet sample return mission (now regrettably cancelled) was called the Champollion Project also referred to as Space Technology 4 (previously Deep Space 4). Champollion was part of the New Millennium program which has a strong emphasis on proving new technology. This spacecraft was due to be launched in 2003 to rendezvous with Comet Temple 1 to survey and map it. It was then proposed to land a small vehicle to undertake drilling the surface of the comet nucleus!. I hope to post archive Web pages of this cancelled Project in the near future.
The International Rosetta Mission was approved in November 1993 by the European Space Agency (ESA) Science Programme Committee as the Planetary Cornerstone Mission in ESA's long-term space science programme. The mission goal is a rendezvous with comet 46 P/Wirtanen. On its eight-year journey to the comet, the spacecraft will pass close to two asteroids, (Otawara and Siwa are now the planned targets). Rosetta will study the nucleus of comet Wirtanen and its environment in great detail for a period of nearly two years, the near-nucleus phase starting at a heliocentric distance of about 3.25 AU, with far-observation activities leading ultimately to close observation (from about one km distance). Rosetta will be launched in January 2003 by an Ariane-5 from Kourou, French Guiana..
There is much more to be found on this subject at the
JPL Comet Hale-Bopp
Home Page. 
(Click on the thumbnail to link to JPL)
If you have any photographs of the comet you may be able to get NASA to publish them (as I have).
Preliminary data on my Comet Hale-Bopp observation
Ecl. Long. and Lat. 352deg 18' 8''
Distance from Earth 1.175 AU (175,780,000 km)
Distance from the Sun 1.009 AU (151,000,000 km) - about the same distance as planet Earth. (An exotic menage a trois!.)
Visual Magnitude -0.408
Copyright © 1997-2002 John Gruson