Essay/Term paper: The hale bopp comet

Essay, term paper, research paper:  Science Reports

The Hale Bopp Comet


As I am sure all of you know, we have recently been able to see a new but not
permanent additon to the night sky. This addition is known as Hale-Bopp, a comet
that is about 122 million miles (about 1.3 times the distance of the sun to the
earth) from the earth and is approximately 25 miles wide. Hale-Bopp was
discovered on July 23,1995 by two scientists named Alan Hale in New Mexico and
Thomas Bopp in Arizona. This is the first discovery for both of them, although
Alan Hale is one of the top visual comet observers in the world, having seen
about 200 comet apparitions. That is one of the reasons they put his name first.
Alan Hale comments, "I love the irony -- I've spent over 400 hours of my
life looking for comets, and haven't found anything, and now, suddenly, when I'm
not looking for one, I get one dumped in my lap. I had obtained an observation
of P/Clark earlier, and needed to wait an hour or so before P/d'Arrest got high
enough to look at, and was just passing the time til then, and I decided to look
at some deep-sky objects in Sagittarius. When I turned to M70, I saw a fuzzy
object in the same field, and almost immediately suspected a comet, since I had
been looking at M70 last month, and *knew* there wasn't any other objects
there."
Thomas Bopp explains his story like this, "On the night of July 22, 1995
some friends and I headed out into the desert for a dark of the moon observing
session. The site, which is west of Stanfield, AZ and a few mile south of
Interstate 8 is about 90 miles southwest from my home.
My friend Jim Stevens had brought his 17-1/2" Dobsonian. We started the
evening observing some of the Messier objects such as the Veil and North
American Nebulae in Cygnus, when Jim said " Let's look at some of the globulars
in Sagittarius." We started our tour with M22 and M28, observing at 50X and then
at 180X. Around 11:00 local time, we had M-70 in the field when Jim went to the
charts to determine the next object of investigation. I continued watching M-70
slowly drift across the field, when it reached a point 3/4 of the way across a
slight glow appeared on the eastern edge. I repositioned the scope to center on
the new object but was unable to resolve it. I called to Jim and asked him if he
knew what it might be, after a visual inspection he stated he wasn't familiar
with it but would check the charts. After determining the general position of
the object he was unable to find it on either Sky Atlas 2000.0 or Uranometria.
The moment Jim said "we might have something" excitement began to grow
among our group and I breathed a silent prayer thanking God for his wondrous
creation. My friend, Kevin Gill then took a position from his digital setting
circles and estimated a magnitude.
At 11:15 I said that we needed to check the object for motion and should
watch it for an hour. The group observed it change position against the star
field over that period and at 12:25 I decided to drive home and report our
finding. Arriving at home initial attempts to send the telegram were
unsuccessful due to an incomplete address I had. After searching my library I
was able to located the correct address and confirmation was requested.
At 8:25 AM July 23, 1995 Daniel Green of the Harvard Smithsonian
Astrophysical Observatory telephoned and said, "Congratulations Tom, I believe
you discovered a new comet." and that was one of the most exciting moments of my
life.
The comet is visible in the evening. Look about 40 degrees west of
North and about 20 degrees off the horizon at about 8:00 p.m. The comet will be
the brightest object in the northwest sky.The comet is traveling at about 28 km
per second and the orbit of this comet is about 4,200 years since the last
appearance and because of gravitational tugs by the planets, especially Jupiter,
the next appearance will be in about 2380 years or the year 4377. Hale-Bopp has
been through our solar system before which surprisingly means it is not a new
comet from the Oort Cloud. Its orbit is a very long, stretched out orbit and the
comet is part of our solar system in orbit around our Sun. Sadly, this excitment
will end in October when Hale-Bopp will disapear to the naked eye. (Special
thanks to Kevin Gill of the Black Mountain Observatory for Alan Hale's and
Thomas Bopp's quotes.)