C/2000 SV74 (LINEAR)

C/2000 SV74 (LINEAR) is another of the many objects that have been reported by LINEAR as an asteroid, in this case of magnitude 17.8, but that are later found to show cometary activity.

The initial observation was made on September 24th 2000 and the object designated 2000 SV74. On October 19th 2000 Milos Tichy noticed a 16" coma and 20" tail on an exposure with the 57-cm reflector at Klet Observatory in the Czech Republic. Later, 5 images of the object were found on LINEAR exposures taken on September 5th 2000.

The comet has a quite strongly hyperbolic orbit (e=1.0048) with perihelion at 3.54AU on April 30th 2002. It has a strongly inclined orbit (i=75º) with perihelion over the north pole of the Earth. As the comet receeds from perihelion it will drop into the southern hermisphere and will finish in the southern polar regions in 2004.

In April 2003 this comet is still showing a well-developed coma despite its large and rapidly increasing heliocentric distance.

The light curve

The CCD Total magnitudes are measured with apertures from 12" to 1.1' and with V, R & I filters. The measures show a large difference in brightness between apertures. This is indicative of a relatively large and difuse object. With a low degree of central condensation the light is spread over a wide area of sky.

Giovanni Sostero notes that the (R-I) colour index that he measures is +0.6, compared to the solar value of +0.4. This indicates that the comet's coma is slightly redder than solar colours due to scattering of light in the coma. The (R-I) colour index is though closer to solar (+0.5) in larger apertures.

The absolute magnitude is nominally quite bright (3.0), although this is partly due to the fact that the comet has a somewhat more rapid rate of brightening (5th power law) with increasing heliocentric distance.

C/2000 SV74 (LINEAR) should stay quite close to its maximum brightness all through 2003, although it is obvious that there is a slow, but systematic fade. This fade appears to have accelerated since late March.

 

 

 

 

 

 

 

 

 

 

 

CCD observations in a 10 arcsecond aperture by:

• Isidro Almendros – MPC 212
• Ramón Naves & Montse Campàs - MPC 213
• Esteban Reina – MPC 232
• Rolando Ligustri - MPC 235
• Albert Sánchez - MPC 442
• Miguel Camarasa - MPC 445
• Julio Castellano – MPC 939
• Fernanda Artigue & Mark Kidger – MPC 954
• Francesc Baldrís – MPC A01
• Josep Lluís Salto – MPC A02
• Quim Moreno – MPC A03

CCD aperture photometry in apertures of 0'.2, 0'.3, 0'.5, 0'.6, 0'.7, 0'.8, 1'.1 by:

• Giovanni Sostero
• R. Ligustri
• P.Beltrame
• M.Narduzzi
• G.Degano
• V.Savani

 

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