StarWatch: Moravian College Astronomy
StarWatch for the greater Lehigh Valley

APRIL  1997
April 6-12 is National Astronomy Week, and the timing coincides perfectly with Comet Hale-Boppís best viewing window. This week will be the prime time for seeing one of the brightest comets of the 20th century. All you have to do is go outside about 75 minutes after sunset and look towards the northwest. H-B will be distinctly visible. Make plans to see it better from a country location with binoculars or visit the Lehigh Valley Amateur Astronomical Society for their Comet Hale-Bopp week of festivities. View the comet through telescopes from Monday through Friday of this week 7-10 p.m. The LVAAS will also be open from 2-10 p.m. on Saturday, with Hale-Bopp viewing after dark. On all dates planetarium programs about the comet will also be given. If you donít know how to get there, phone 610-797-3476 or connect with the web site below to obtain directions and a map. Follow the daily progress of the comet at this web location too! The map below is courtesy of Sky and Telescope.

Find out more about the LVAAS.

Monday, April 7:
Tonight was another great evening to view Comet Hale-Bopp as weather conditions improved throughout the day rather than deteriorate as they originally were predicted to do. Although not as windy and crystal clear as observing on April 1; the compromise was more temperate weather conditions. Tonight the comet could be viewed in comfort with only a light jacket. Hale-Bopp should be at its greatest brilliance this week, although to me its luminosity has been relatively steady for the past several weeks. Comets usually peak several weeks after being closest to the sun. H-B's closest approach was on April 1. Tonight a milky white dust tail with numerous striations arched about 10 degree away from the head of the comet. Without optical aid the tail seemed to extend about 9 degrees. Through binoculars the faint ion (gas) tail extended upward diverging from the curve of the dust tail. The ion tail actually produces its own light, and it was responsible for most of the light output from Comet Hyakutake which was in our sky just one year ago. Overwhelmingly, throughout the history of Hale-Bopp, the light output has come from its dust tail. Comets traditionally obtain most of their brilliance from the light reflected (actually scattered) from the dust which is released as their ices sublime.

Wednesday, April 9:
WOW! Did the comet shine tonight. However, it was cold enough to freeze "Sarah Lee's buns." And the wind didn't help either. My good friend, Adam Jones, and I went to Pulpit Rock for our final photographic fling. Armed with a 300 mm, F/4.5, ED Nikor lens, we went for broke, and did just that. The results were disappointing because of the wind. One of the images will probably appear on this sight, but a few of the stars will have to be "rounded." Through the lens H-B's tail spanned the entire field of view, about 6-7 degrees. Visually, the comet was spectacular with its broad dust tail curving about 10+ degrees away from a beautiful, stellar coma. The ion tail was also plainly seen. We photographed until 10:15 p.m. Adam forgot his gloves. I by chance brought along a second pair.

Thursday, April 10:
A waxing crescent moon to the left of Hale-Bopp and some haze made the comet appear somewhat dimmer (about the brightness of +0.05 magnitude Capella) this evening. Still, through binoculars, H-B was a beautiful sight, with the comet's head slightly above 3.7 magnitude Rho Persei and the tail arcing over Algol, the Demon star. The star to the right of Rho was 4.7 magnitude Pi Persei. Visually the tail appeared about 5 degrees in length, but through binoculars it extended across the entire field, and then some.

Friday, April 11:
Just a quick peak outside around 10:45 p.m. found Hale-Bopp low in the northwest with a slight appendage for a tail. Hazy conditions and a waxing crescent moon made H-B appear fainter than zero magnitude Capella this evening.

Comet Hale-Bopp finder chart
033    APRIL 13, 1997:   Moon Affects Hale-Bopp Spectacular
The growing brightness of the moon will definitely affect your viewing of Hale-Bopp over the next 10 days. The comet should also begin a very slow but steady dimming as it moves farther away from the earth and sun and its positioning in the northwest after sundown becomes a little less favorable. But donít despair; by late April when the comet is again visible in a moonless sky, you will have one last chance to observe one of the great comets of the 20th century. In the meantime, look towards the west, northwest, about an hour after sunset and one third of the way up in the sky. The comet will be there. Watch the moon approach the planet Mars as the week progresses. Late Friday, into early Saturday morning, Mars will be positioned about eight lunar diameters (4 degrees) above a nearly full moon. Follow the progress of H-B at the web address below.

Tuesday, April 14:
Under a waxing gibbous moon, Hale-Bopp appeared about one half magnitude fainter than the star Capella which is almost directly above it. The dust tail extended about 4 degrees as viewed with binoculars, and was distinctly visible with the unaided eye. The comet has been moving away from the sun and earth since April 1, so it will be only a matter of time before it starts to fade. In about 8 days when the moon is out of the picture, a true assessment of the comet's brightness will be easier to make. As the comet has moved from the northwest to the west northwest over the past several weeks the tail has been pointing more vertically up from the horizon. A month ago when H-B was first seen in the evening sky, its tail was nearly parallel to the horizon.
034    APRIL 20, 1997:   Follow the Arc of the Dipper Handle
After you have checked on the progress of Comet Hale-Bopp about one and one half hours after sunset in the WNW, turn your attention to the seven stars of the Big Dipper high in the northeast. The Dipperís handle will no longer be pointing straight down, but it will appear to arc towards the east. Follow the curve of the handle and you will come to a bright reddish star, Arcturus, in the constellation of Bootes, the Herdsman or Bear Driver. Continuing along the curve will bring you to blue-white Spica, the principal star of the constellation of Virgo, the Virgin. On Tuesday, the nearly full moon will be just below Spica making it difficult to spot without the aid of binoculars. Moonlight, towards the end of the week becomes less of a hassle. Each night, at this time of the year, the moon rises about an hour later. By week's end, you may want to repeat the Dipper observations under more favorable conditions to see how harsh moonlight adversely affects the visibility of stars. The map is courtesy of Sky and Telescope.

Saturday, April 26:
With the moon gone from the early evening hours, it is now possible to see Comet Hale-Bopp in a darker sky. This clear, mild night was perfect for comet viewing. At about 9:15 p.m., the comet was spotted about 20 degrees off the WNW horizon in Coopersburg, still shining brightly with a 3-4 degree tail. Through binoculars the tail covered the entire field, 7 degrees. Hale-Bopp is growing dimmer. Its magnitude was about +1.0, about six times fainter than when it was at its brightest. It is still putting on a very nice show and worth monitoring.

Comet Hale-Bopp finder chart
More Comet postings in StarWatch for Mar., Feb., or scroll above.
035    APRIL 27, 1997:   Life After Hale-Bopp
Comet Hale-Bopp is now on the wane, but it can still be seen low in the west about 90 minutes after sunset if your horizons are good enough. Postpaid souvenir Hale-Bopp comet packets, including two original photos, locator map, and commentary are available for $5.00 apiece from the ASD Planetarium, Dieruff High School, 815 N. Irving Street, Allentown, PA 18103-1894. Checks should be make payable to the ASD Planetarium. H-B packets can also be purchased from Danís Camera City--610-434-2313. More about the comet photo sale can be found at the Planetariumís web site noted below. Is there life after Hale-Bopp? You bet! Check the southeastern sky around 4:30 a.m. to see bright Jupiter which is located in the constellation of Capricornus, the Sea Goat. Interestingly, Uranus and Neptune are located in the same constellation, slightly above and to the right of Jupiter, but invisible without optical aid. The thin crescent moon will be near Jupiter on Wednesday and Thursday mornings. The map is courtesy of Sky and Telescope.
Comet Hale-Bopp finder chart