Comet Arena – Rigo (49P / Arend-Rigaux) is a short-period comet from the Jupiter family, which was discovered on February 5, 1951 by Belgian astronomers Sylvain Aren and Fernand Rigaux at the Royal Observatory of Belgium during routine asteroid observations. It has been described as a diffuse object of 11 m magnitude. The comet has a fairly short orbital period around the Sun – just over 6.7 years.


The orbit of comet Arena – Rigo and its position in the solar system




Observation history

1951 was extremely favorable for observing this comet; astronomers have repeatedly noted that it has a coma and a tail. But the next return in 1958 was somewhat different: although the comet was found very close to the predicted position, for three weeks of observations it showed practically no cometary activity and only the coincidence of the orbital parameters indicated that it was indeed a comet, and not some asteroid. The same thing happened during the comet’s return in 1963 and 1970. Only the return of 1978 allowed astronomers to re-discover the faint coma and tail, thereby confirming the cometary nature of the object.

It is interesting that the comet’s orbit is characterized by a rather long period of stability: as calculations have shown over the past 900 years, the comet has never approached Jupiter closer than 0.9 AU. e. (135 million km) and a similar situation will continue for several more centuries, until the XXIV century, in which two close encounters with Jupiter are expected at once. But on December 20, 2058, the comet will pass at 0.0867 AU. e. (13.005 million km) from Mars.