JOSEPH DE CA'TH LON DISCOVERS THE COMET HALE-BOPP

Joseph de Ca'th Lon in Arizona Desert

I was astonished first time I saw it. It was like a big fired arrow crossing the starred sky. 

I felt very small in the middle of our unknown Universe.

My interest in Astronomy is old, since I was a teenager. I have always had an incredible feeling to look up into the sky.

The sky is a big map and we can find past answers, present mysteries and it will be a useful guide for the future generations. 

Joseph de Ca'th Lon, New Mexico, 1995

Comet Hale–Bopp, formally designated C/1995 O1, is a comet that was perhaps the most widely observed of the 20th century, and one of the brightest seen for many decades.

Joseph and Hale-Bopp in Cairo

Hale–Bopp was discovered on July 23, 1995 separately by Alan Hale and Thomas Bopp prior to it becoming naked-eye visible on Earth. 

Although predicting the maximum apparent brightness of new comets with any degree of certainty is difficult, Hale–Bopp met or exceeded most predictions when it passed perihelion on April 1, 1997. 

It was visible to the naked eye for a record 18 months, twice as long as the previous record holder, the Great Comet of 1811. 

Accordingly, Hale–Bopp was dubbed the Great Comet of 1997.

More information: NASA

Hale had spent many hundreds of hours searching for comets without success, and was tracking known comets from his driveway in New Mexico when he chanced upon Hale–Bopp just after midnight. The comet had an apparent magnitude of 10.5 and lay near the globular cluster M70 in the constellation of Sagittarius. 

Joseph and Hale-Bopp over Indian Cove, 2013

Hale first established that there was no other deep-sky object near M70, and then consulted a directory of known comets, finding that none were known to be in this area of the sky. 

Once he had established that the object was moving relative to the background stars, he emailed the Central Bureau for Astronomical Telegrams, the clearing house for astronomical discoveries.

Bopp did not own a telescope. He was out with friends near Stanfield, Arizona observing star clusters and galaxies when he chanced across the comet while at the eyepiece of his friend's telescope. He realized he might have spotted something new when, like Hale, he checked his star maps to determine if any other deep-sky objects were known to be near M70, and found that there were none. He alerted the Central Bureau for Astronomical Telegrams through a Western Union telegram. 

Brian G. Marsden, who had run the bureau since 1968, laughed, Nobody sends telegrams anymore. I mean, by the time that telegram got here, Alan Hale had already e-mailed us three times with updated coordinates.

More information: Space

The following morning, it was confirmed that this was a new comet, and it was given the designation C/1995 O1. The discovery was announced in International Astronomical Union circular 6187.

Hale–Bopp's orbital position was calculated as 7.2 astronomical units (AU) from the Sun, placing it between Jupiter and Saturn and by far the greatest distance from Earth at which a comet had been discovered by amateurs.Most comets at this distance are extremely faint, and show no discernible activity, but Hale–Bopp already had an observable coma. 

Joseph and Comet Hale-Bopp over Lake Mono

An image taken at the Anglo-Australian Telescope in 1993 was found to show the then-unnoticed comet some 13 AU from the Sun, a distance at which most comets are essentially unobservable. Analysis indicated later that its comet nucleus was 60±20 kilometres in diameter, approximately six times the size of Halley.

Its great distance and surprising activity indicated that comet Hale–Bopp might become very bright indeed when it reached perihelion in 1997. However, comet scientists were wary, comets can be extremely unpredictable, and many have large outbursts at great distance only to diminish in brightness later. Comet Kohoutek in 1973 had been touted as a 'comet of the century' and turned out to be unspectacular.

The comet likely made its previous perihelion 4,200 years ago, in July 2215 BCE. The estimated closest approach to Earth was 1.4 AU, and it may have been observed in ancient Egypt during the 6th dynasty reign of the Pharaoh Pepi II (Reign: 2247 - c.2216 BCE). 

Pepi's pyramid at Saqqara contains a text referring to an "nhh-star" as a companion of the pharaoh in the heavens, where "nhh" is the hieroglyph for long hair.

More information: Phys

 Reality is determined not by what scientists or anyone else says or believes but by what the evidence reveals to us.

Alan Hale