29P/Schwassmann-Wachmann 1

29P/Schwassmann-Wachmann 1 was discovered on January 17th 1929 by Schwassmann and Wachmann at Hamburg at magnitude 11, but rapidly faded to magnitude 16. Later, observations were discovered of the comet at outburst to magnitude 12 in 1902.

29P/Schwassmann-Wachmann 1 is an exceptional object in many ways. Nominally it has been seen at 6 returns to perihelion (1908, 1925, 1941, 1957, 1974 & 1989) but, in reality, its almost circular orbit - eccentricity 0.045 - means that its distance from the Sun hardly varies. The comet has a perihelion distance of 5.77AU and a period of 14.9 years; thus its orbit is almost circular outside that of Jupiter. However, both the eccentricity and the period have decreased steadily over the last century, the period from 16.44 years and the eccentricity from 0.15.

Studies of the light curve over the years have shown that outbursts of the kind observed at discovery are common. At least one a year occurs, despite the fact that the comet is at a heliocentric distance where most objects are inactive or barely active. The magnitude is about 17 in quiescence, but has risen to 9.4 in the largest known outburst. The mechanism of the outbursts is unknown, but their pattern is fairly consistent with the formation of an intense stellar nucleus and a rise in brightness over a few hours or days. The coma expands and forms spiral jets, before fading slowly. The mechanism of the outbursts is currently unknown.

The light curve

29P/Schwassmann-Wachmann 1 can be observed every year around the time of opposition. The light curve here is made up of CCD photometry in R with a 10" aperture (shown as m2),CCD.Tot all magnitude with apertures of up to 1' and visual magnitude estimates.  

The comet has been very active in 2002 (see the light curve left) with a small outburst in July and a large one in August that reached magnitude 12. Although the August 2002 outburst is far from being a record, it is an unusually large one. Two small outbursts are recorded in October, the first is only poorly sampled, but the second is well covered on the rise to maximum, one of the rare occasions when the rise is very well observed. An unusual event in November has been the observation of a double outburst with two important maxima in less than 2 weeks.

Note that the very condensed nature of the coma in outburst means that there is very little difference between the estimates of the total visual magnitude and the CCD measures in a 10" aperture.

A long-term project to study the light curve of the comet is in progress. 

Light Curve 2001

Light curve 2002

 

 

 

 

 

Observations from:

  • Ramón Naves & Montse Campàs - MPC 213
  • Rolando Ligustri - MPC 235
  • Albert Sánchez - MPC 442
  • Miguel Camarasa - MPC 445
  • Juan Rodríguez & Salvador Sánchez - MPC 620
  • Fernanda Artigue - MPC 844
  • Fabiola Martín-Luis - MPC 954
  • Josep Lluis Salto - MPC A02
  • Juan Lacruz - MPC J87
  • Carles Pineda - MPC J91
  • Toni Climent - MPC J97

CCD total magnitude estimates in 0'.4, 0'.5 and 1'.0 apertures by:

  • Giovanni Sostero
  • R.Ligustri
  • V.Savani
  • L.Guatto

Visual estimates from:

  • Rafael Benavides

 

Animation: September 27/28th 2002

An animation composed of three 300s exposures taken with a 0.82-m f/15 Cassegrain + Thompson CCD + R from Teide Observatory (Tenerife, Spain).

The comet is the slightly difuse object in the centre that moves very slightly from right to left between the three frames. The faint coma is a residual of the big outburst observed in early August. The images were taken through cirrus cloud, hence the variation in the visibility of the coma.

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Fabiola Martín-Luis. Animation prepared by: Ramón Naves
MPC 954, Observatorio del Teide (Tenerife, Spain)

 

 

  

Image: October 20th 2002

Image of 29P/Schwassmann-Wachmann 1 taken with a 0.30-m f/6.5 Schmidt-Cassegrain + ST9-E CCD from close to Barcelona (Spain).

After a small outburst that peaked approximately a week and a half before the comet has faded considerably.

Ramón Naves & Montse Campàs
MPC 213, OBSERVATORIO MONTCABRER CABRILS (SPAIN)
 

 

 

 

 

 

Image: October 22nd 2002 Image of 29P/Schwassmann-Wachmann 1 taken with a 0.31-m Schmidt-Cassegrain + CCD from close to Barcelona (Spain).

This image catches the comet on the rise as a new outburst initiates, although still close to minimum light.

Albert Sánchez
MPC 442, Observatorio Gualba (SPAIN)

 

 

 

Image: October 25th 2002

Image of 29P/Schwassmann-Wachmann 1 taken with a 0.30-m f/6.5 Schmidt-Cassegrain + ST9-E CCD from close to Barcelona (Spain).

This image records the onset of a new outburst that has been caught on the rise. The coma is very concentrated with an almost stellar nucleus.

Ramón Naves & Montse Campàs
MPC 213, OBSERVATORIO MONTCABRER CABRILS (SPAIN)
 

 

 

 

Image: October 26th 2002

Image of 29P/Schwassmann-Wachmann 1 taken with a 0.30-m f/6.5 Schmidt-Cassegrain + ST9-E CCD from close to Barcelona (Spain).

This image records the rise of the new outburst. The coma continues to be very concentrated.

Ramón Naves & Montse Campàs
 MPC 213, OBSERVATORIO MONTCABRER CABRILS (SPAIN)
 

 

 

Image: November 10th 2002

Image of 29P/Schwassmann-Wachmann 1 taken with a 0.31-m Schmidt-Cassegrain + CCD from close to Barcelona (Spain).

This image catches the comet during another new outburst, the second in less than 2 weeks.

Albert Sánchez
MPC 442, Observatorio Gualba (SPAIN)

 

 

 

 

 

Image: May 22nd 2003

Image of an outburst of 29P/Schwassmann-Wachmann 1. 30cm S/C + ST9E CCD.

Jaime Nomen & Salvador Sánchez

MPC 620, Observatorio Astronómico de Mallorca

 

 


Última actualización 12/06/2003
Por M.R.Kidger