Bennett (Ben)

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Jack Bennett

If Charles Messier was the guardian of the Northern sky, Jack Bennett was undoubtedly his counterpart for the Southern Hemisphere. Often called the "Southern Messier," Bennett created a database that has become the definitive guide for deep-sky observers south of the equator.

While most modern catalogs are made for the beauty of the objects, Bennett’s list—like Messier’s—was born out of a very practical, slightly annoyed need to stop looking at things that weren't comets.

Astronomer Jack Bennett, born on April 6th, 1914, and passing away on May 30th, 1990, was a prominent figure in the Astronomical Society of Southern Africa (ASSA). Serving as ASSA President in 1969, he received the Gill Medal in 1970 and an Honorary Degree of Master of Science from the University of Witwatersrand in 1986. The asteroid VD 4093 was named after him in 1989 at the recommendation of Rob McNaught of Siding Springs Observatory.

Jack's interest in astronomy began during his teenage years when his mother introduced him to the Southern Cross and celestial bodies.

Known for his keen observational skills, Bennett compiled two lists of southern objects with comet-like appearances. His 1969 list, published before discovering his first comet, and the 1974 supplementary list featured 22 new comet-like objects. Bennett's 1969 Presidential Address outlined his efforts in recognizing comet-like objects in the Southern sky.

Jack's passion for comets led to the compilation of lists published in MNASSA in 1969 and 1974. However, seeing conditions deteriorated due to light pollution, affecting his observations. He served as the Director of the ASSA Comet & Meteor Section and associated with the IAU Commission 20 (Comets). Jack's significant contributions were recognized with the 'Nova Award' from AAVSO in 1976.

The lists created by Bennett culminated in the Bennett Catalogue, comprising 152 celestial objects, including the Tarantula, Omega Centauri, 47 Tucanae, Sombrero, and the Silver Coin. Notably, 26 of Messier's objects were listed. Bennett, cautioning about potential mistakes, emphasized the surprising ease of confusing even bright objects for comets under specific conditions.

Globular clusters dominated Bennett's list, particularly in Sagittarius and Ophiuchus. The constellation Dorado housed numerous objects within the Large Magellanic Cloud, with Bennett advising caution in seeking comets in this region.

Jack's astronomical instruments included a 3-inch refractor, 10x60 binoculars, a Celestron telescope, and his favorite - a 5-inch refractor for "low power" observing. Notably, he discovered a 9th magnitude supernova in M83 in 1968 and his first comet in Tucana in 1969, which became a prominent naked-eye object.

History & Who Made It

John Caister "Jack" Bennett (1914–1990) was a South African civil servant and legendary amateur astronomer. Based in Pretoria, he spent hundreds of hours in his backyard with a 5-inch low-power refractor, scanning the skies for comets.

In 1969, Bennett published his first list of 130 objects. He updated this in 1974 with a supplementary list of 22 more. These were combined into what we now call the Bennett Catalog. Jack was a master of the "low power" view; he didn't use massive equipment, proving that patience and a dark South African sky were the best tools an astronomer could have.

The Purpose: The Comet Hunter's Warning

The primary goal was to catalog "comet-like" objects. In the 1960s, before digital imaging, a fuzzy blob in a small telescope could easily be mistaken for a new comet.

Bennett wanted to save himself (and other southern observers) the time of reporting a "new discovery" only to realize it was just a known nebula or cluster. Interestingly, his list includes some of the most famous objects in the sky—like Omega Centauri and the Tarantula Nebula—because through a small telescope, even these giants can mimic the hazy head of a comet.

What Objects Can Be Found In It?

The catalog is famous for being incredibly "heavy" on globular clusters. This is because, at low magnification, a distant globular cluster looks almost identical to a tailless comet.

The Breakdown (152 Objects Total):

• 72 Globular Clusters: Nearly half the list. These are the "trickiest" objects for comet hunters.

• 46 Galaxies: Including the "Silver Coin" (NGC 253) and the "Sombrero Galaxy" (M104).

• 22 Open Clusters: Such as those found on the outskirts of the Magellanic Clouds.

• 9 Planetary Nebulae: Small, ghostly shells of dead stars.

• 3 Bright Nebulae: Including the vast star-forming regions of the southern Milky Way.

The Bennett Catalog (Flat Text Summary)

Catalog Name: The Bennett Catalog Creator: Jack Bennett (Pretoria, South Africa) First Published: 1969 (Updated 1974) Total Objects: 152 Primary Equipment: 5-inch (125mm) Refractor at 21x magnification

Object Category: Count Globular Clusters: 72 Galaxies: 46 Open Clusters: 22 Planetary Nebulae: 9 Diffuse/Bright Nebulae: 3

Famous "Bennett" Gems:

• Ben 2: NGC 104 (47 Tucanae - arguably the best globular in the sky)

• Ben 4: NGC 253 (The Sculptor Galaxy)

• Ben 35: NGC 2070 (The Tarantula Nebula)

• Ben 65: NGC 5139 (Omega Centauri)

• Ben 129: NGC 6523 (The Lagoon Nebula / M8)

A True Legend

Jack Bennett's legacy isn't just his list. In 1968, he became the first person ever to visually discover a supernova (SN 1968L in the galaxy M83) since the invention of the telescope. His catalog remains the primary challenge for southern observers who want to experience the sky exactly as the great comet hunters did.

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