Hale Bopp: comet of the century?

Observer's reports: January, 1997

From: Bill Arnett billa@ZNET.COM
Date: Wed, 29 Jan 1997 06:10:07 -0800
Subject: What am I doing up at this ungodly hour?

Seeing Hale-Bopp, of course. From my balcony in the middle of San Jose, I can easily see it naked-eye even thru the horrendous light pollution. I could see only about 1/4 degree of tail. And I'm unable to make a useful magnitude estimate; the sky background varies so much that all the nearby comparison stars seem to be in the wrong relations to each other let alone to Hale-Bopp. I hate cities!

From: George Zay GeoZay@aol.com
Date: Wed, 29 Jan 1997 12:02:48 -0500 (EST)
Subject: Hale/Bopp Observation Jan 29 ZAYGE

I observed Hale/Bopp thru 7X50 binoculars on Jan 29th. I had a Limiting magnitude near 5.0 from my workplace in La Mesa, Ca. Between the times of 0508-0525 hrs PST, I can see the comet very easy in the North East with the naked eye. To me it still appears as a star though. Thru the binoculars, I see a tail that appears to be about 1 degree long pointing towards the North. As for approximate magnitude. I compared it with zeta Aquilae again, although it is a lot closer to Gamma Aquilae. I didn't know Gamma Aql's magnitude, but I did for Zeta. Thus after comparing Zeta Aql and Hale/Bopp several times, I mentally condensed the coma to a star point image. Then added the fuzziness of the remainder of the comet in a condensed form. My estimate for Hale/Bopps magnitude is between 2.7 and 2.9. I believe this is pretty close to what I saw during my last sighting on Jan 20? I get the impression that it's stuck on this magnitude range for the moment. If you need help finding HB, look for Altair and measure a little less than 1 fist above and to the left. (this is 1 fist to the North and West of Altair).

From: byen@ix.netcom.com (B Yen)
970115116 Observing Jan 11
Date: Tue, 14 Jan 1997 06:35:16 -0800

I finally got a clear observing session last Saturday morning (Jan. 11), from Mojave Desert. 1 hr ago, I developed the TechPan neg from 8" f1.5 Schmidt Camera, and there is clearly an anti-tail (1.86 deg, broad-diffuse -- longer than the 1.25 deg main tail!). It also shows up on a color shot, on Fuji SG800+ film. In fact, on a medium-format horizon shot with 165mm lens (on Kodak PMZ1000), it is also noticeable (just eyeballing the negative)! I roughly aligned the neg with Tirion's Sky Atlas, and came up with the following:

• main tail PA 330 deg, 1.25 deg long
• anti-tail PA 200 deg, 1.86 deg long (diffuse, broad)
• "spiral tail" PA 20 deg, very short (it seems to be diametrically opposite anti-tail & might be the anti-tail's "origin" jet)

12:00 UT Jan 11, Mojave Desert fan-like appearance in 7x50 binoculars & 8x50 finderscope remained visible in strong twilight

My friend Bob Mortimer reported this observation to me:

12:45 UT Jan 9, San Bernardino, California slight bluish appearance in German 10x80 flak (the infamous 88mm) binoculars, 1.5 deg tail. Magnitude was 1 mag brighter than M13 (mag 4.5) Noticed fan-like appearance.

Using Russian image intensifier binoculars, observed 1 bright jet (gas tail) sandwiched between 2 "dust" tails, 45 deg separation.

Note: this is the ONLY visual observation that I've seen which corroborates with the 3 tails I see on my photo. On COHP, there is only 1 observation (from Spain), which notes PA very accurately (but for only 2 tails).

Anti-tail is "angled", as per the prediction by Tom Polakis on s.a.a. 12/19/95 (see http://www.psiaz.com/polakis/antitail/antitail.html . The earth passed through plane of H-B orbit on Jan. 2, so anytime afterward an angled anti-tail is expected). H-B anti-tail looks quite similar to Tom's sketch of Comet Bradfield (with angled anti-tail).

Hale-Bopp viewed / Split nucleus?
From: mctaylor@mindspring.com (Mark Taylor)
Date: Sat, 11 Jan 1997 19:20:13 -0500

I viewed Hale-Bopp this morning from Fremont Peak in central California, at approximately Jan 11, 1997 13:30 UTC.

It was an easy naked-eye object, quite nice in 10x binoculars, and very nice through 77x through my telescope.

It was just a "spot" (not a pinpoint) to the naked eye - a little smaller than the moon. There was a noticable tail when looking through the binos, and I could see multiple streams in the tail through the telescope. The tail extended beyond one field of view on my 8" f/10 w/26mm plossl. Note that all of this is through pre-dawn glow. I'm sure there was more there than could be detected.

One interesting thing that I noticed was the nucleus: It was not a uniform "round spot" in the coma. It appeared to be elongated in the same direction as the tail. Under higher power (200x) this shape was even more certain to me.

Has anyone else seen this? My first thought was "I wonder if it has split in two? Wouldn't that be a nice site -- "twin comets" blazing along together in our March/April skies!!" (assuming such a trauma wouldn't make it fizzle out altogether)

Here's hoping for a great show...

From: JOHN LEPPERT
Date: Wed, 08 Jan 1997 09:13:46 -0800
Subject: Comet Hale-Bopp observation report - January 08

January 8. I left the comfort of the house for the observatory at 5:45 under a clear sky, calm winds, and a temperature of -18oF. This morning's ephemeris for Comet Hale-Bopp listed its position as 18hr54.2 min min RA and 6o43' DEC at 5:48 local time when it was scheduled to rise at 79.8o in azimuth. After placing the 8x56 binoculars and tripod out on the observatory deck, and the 4-inch Dynascope in its polar aligned mounting cradle that had been attached to the SCT tripod several days ago outisde the east wall of the observatory, I first sighted the comet naked eye at 6:10 when it was only 3.7o altitude and 83.9o azimuth (using SkyGlobe v. 3.6 software); thereafter I spent thirty minutes using the binoculars and Newtonian before it was obscured by lower level cloud, which dissipated shortly before our 8:29 sunrise. Afterwards, while use DeepSpace v. 5.21 software and a star plot sketch of the inverted telescope field, I made some measurements of field stars. With the comet field-centered in a 46x ocular, the following stars magnitudes, position angles, and star-comet nucleus separation distances were calculated: 5.6 mag, PA 160o, 20'; 9.0 mag, PA 5o, 8'; 9.1 mag, PA 330o, 25'; and 9.2 mag, PA 290o; the comet remains near 3.5 magnitude. An observing log that includes time, altitude, and azimuth positions follows:

6:10   3.7o  83.9o  sighted naked eye

6:21   5.5o  86.0o

6:30   7.0o  87.7o  made rough field sketch

6.40   8.6o  89.5o  last sighting because of cloud

(This was the fifth time the comet has been viewed as a pre-dawn object since recovering it December 26.)

From: JOHN LEPPERT
Date: Thu, 02 Jan 1997 09:32:09 -0800
Subject: Hale-Bopp observation - January 02

January 2. I walked out of the house at a quarter past five under a fine clear sky ablaze with the stars of late spring, easy 5th magnitude even though the waning crescent Moon, just past last quarter phase, stood well more then 30o due south with Spica 8o to its lower left and bright ruddy Mars 18o to its upper right. Remarkably the calm air felt tropical; as I was to discover upon reaching the observatory office, the temperature stood at 31o and as the recording thermometer graph showed, we'd reached 36o a couple hours after midnight -- the first time I'd seen it rise above freezing since in the last 57 days (November 6). Ah --- if only winter were indeed on the wane. The calendar and near 30-inch prairie snow cover betrays any likelihood of that being the case.

Using SkyGlobe 3.6 and DeepSpace 5.21 software, I determined that Comet Hale- Bopp was to rise at 6:11 at 82.4o in azimuth, and then decided to take advantage of the warm morning and set the tripod mounted 8x56 binoculars outside on the observatory deck, rather then viewing through the office window as I'd done on the first two morning sightings (December 26 and 29) when it was nearly 60 degrees colder in the -30o range. I recovered the comet at 6:31 when it was nearly due east just as astronomical twilight began (of- ficially at 6:35) and nearly two hours before sunrise (officially at 8:30). An observing log follows including time, altitude and azimuth positions:

6:31   3.6o  86.1o  first sighting in binoculars

6:34   4.1o  86.7o

6:49   6.7o  89.6o  sighted naked eye

7:00   8.5o  91.6o

7:08   9.7o  93.2o

7:15  10.9o  94.5o  lost naked eye; Altair 2.8o 79.6o

7:30  13.3o  97.4o

7:36  14.3o  98.6o  last sighting; Sun -8.2o 115.6o; Venus 4.9o 132.7o

There was a 5.1 magnitude star 5o48' to Hale-Bopp's lower left, a 5.8 mag- nitude star 23' northeast, and a 5.4 magnitude star 2o32' to its upper right. The ephemeris listed the comet's coordinates for 7 o'clock as being 18hr44.8 RA and 5o09' DEC. I'd estimate the coma as being near 3.5 magnitude, and the tail extended towards the northeast just above the 23' separated star and beyond about another degree or so. Several jets were just visible, appearing near the 7 o'clock PA. I must get the old 4-inch Dynascope set up outside the observatory today, since the comet is too low to be seen with the SCT from within the building.