57P/Du Toit-Neujmin-Delaporte

57P/Du Toit-Neujmin-Delaporte has been observed at 6 appearances (1941, 1970, 1983, 1989, 1996 & 2002). The comet was discovered on July 18th 1941, from Boyden in South Africa, as a 10th magnitude object during what was obviously a large outburst. The naming of this comet is an example of how despite the World War being at its height astronomy continued to work. Du Toit cabled Harvard College Observatory with his discovery, but the cable took 9 days to arrive. Meanwhile, on the 25^th Neujmin had independently located the comet in Crimea, by then under threat from the German invasion of the Soviet Union. Neujmin contacted Moscow who radiogrammed his discovery to Harvard, although it did not arrive until mid-August. Finally, in German-occupied Belgium, Delaporte found the comet at Uccle on August 19^th. When finally Harvard could announce the comet on August 22^nd 1941 there were now three independent discoveries. 

The orbit was somewhat uncertain and the next two perihelion passages, in 1946 and 1952 were missed. Careful searches in 1958 failed and the comet was then almost forgotten until Charles Kowal recovered it unexpectedly in 1970 at magnitude 18.5. Apart from the badly placed 1976 return the comet has since been seen at every apparition.

The comet's current period is 6.42 years, although this may vary quite significantly due to fairly close approaches to Jupiter.

In 1996 the comet outburst to magnitude 12 and is suspected to have fragmented. A major fragmentation has occurred in 2002. In total 18 fragments have been observed.

The 2002 apparition

57P has been unusually bright at its 2002 return, undoubtedly due to the major fragmentation that it has sufffered and is close to the expected peak brightness in August. We can see that there is a slow fade in the data. However, given that the heliocentric distance is only increasing slowly, this is equivalent to a very rapid fade in real terms. Maximum was reached in late July/early August, at or slightly before perihelion.
 
 
 
 

CCD observations in a 10 arcsecond aperture by:

• Ramón Naves & Montse Campàs - MPC 213
• Rolando Ligustri - MPC 235
• Albert Sánchez - MPC 442
• Miguel Camarasa - MPC 445
• Salvador Sánchez & Juan Rodríguez - MPC 620
• Fabiola Martín-Luis - MPC 954
• Carles Pineda - MPC J91
• Toni Climent - MPC J97

CCD total magnitudes in apertures of 0'.2 and 1'.0 by:

• Rolando Ligustri
• Giovanni Sostero