The Hale Bopp CometAs I am sure all of you know, we have recently been able to see a new but notpermanent additon to the night sky. This addition is known as Hale-Bopp, a cometthat is about 122 million miles (about 1. 3 times the distance of the sun to theearth) from the earth and is approximately 25 miles wide.
Hale-Bopp wasdiscovered on July 23,1995 by two scientists named Alan Hale in New Mexico andThomas Bopp in Arizona. This is the first discovery for both of them, althoughAlan Hale is one of the top visual comet observers in the world, having seenabout 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 mylife looking for comets, and haven’t found anything, and now, suddenly, when I’mnot looking for one, I get one dumped in my lap. I had obtained an observationof P/Clark earlier, and needed to wait an hour or so before P/d’Arrest got highenough to look at, and was just passing the time til then, and I decided to lookat some deep-sky objects in Sagittarius.
When I turned to M70, I saw a fuzzyobject in the same field, and almost immediately suspected a comet, since I hadbeen looking at M70 last month, and *knew* there wasn’t any other objectsthere. “Thomas Bopp explains his story like this, “On the night of July 22, 1995some friends and I headed out into the desert for a dark of the moon observingsession. The site, which is west of Stanfield, AZ and a few mile south ofInterstate 8 is about 90 miles southwest from my home. My friend Jim Stevens had brought his 17-1/2″ Dobsonian. We started theevening observing some of the Messier objects such as the Veil and NorthAmerican Nebulae in Cygnus, when Jim said ” Let’s look at some of the globularsin Sagittarius. ” We started our tour with M22 and M28, observing at 50X and thenat 180X.
Around 11:00 local time, we had M-70 in the field when Jim went to thecharts to determine the next object of investigation. I continued watching M-70slowly drift across the field, when it reached a point 3/4 of the way across aslight glow appeared on the eastern edge. I repositioned the scope to center onthe new object but was unable to resolve it. I called to Jim and asked him if heknew what it might be, after a visual inspection he stated he wasn’t familiarwith it but would check the charts. After determining the general position ofthe 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 growamong our group and I breathed a silent prayer thanking God for his wondrouscreation. My friend, Kevin Gill then took a position from his digital settingcircles and estimated a magnitude. At 11:15 I said that we needed to check the object for motion and shouldwatch it for an hour. The group observed it change position against the starfield over that period and at 12:25 I decided to drive home and report ourfinding.
Arriving at home initial attempts to send the telegram wereunsuccessful due to an incomplete address I had. After searching my library Iwas able to located the correct address and confirmation was requested. At 8:25 AM July 23, 1995 Daniel Green of the Harvard SmithsonianAstrophysical Observatory telephoned and said, “Congratulations Tom, I believeyou discovered a new comet. ” and that was one of the most exciting moments of mylife. The comet is visible in the evening.
Look about 40 degrees west ofNorth and about 20 degrees off the horizon at about 8:00 p. m. The comet will bethe brightest object in the northwest sky. The comet is traveling at about 28 kmper second and the orbit of this comet is about 4,200 years since the lastappearance 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 hasbeen through our solar system before which surprisingly means it is not a newcomet from the Oort Cloud.
Its orbit is a very long, stretched out orbit and thecomet is part of our solar system in orbit around our Sun. Sadly, this excitmentwill end in October when Hale-Bopp will disapear to the naked eye. (Specialthanks to Kevin Gill of the Black Mountain Observatory for Alan Hale’s andThomas Bopp’s quotes.)