RT Journal Article
T1 Observations of a very bright fireball and its likely link with comet C/1919 Q2 Metcalf
A1 Trigo Rodríguez, Josep María
A1 Madiedo Gil, José María
A1 Williams, I. P.
A1 Castro Tirado, Alberto J.
A1 Llorca, Jordi
A1 Vítek, Stanislav
A1 Jelinek, M.
AB A very bright fireball called B´ejar (SPMN110708), with a maximum brightness of −18, wasobserved over much of Spain as well as parts of Portugal and France on 2008 July 11 at21:17:39 UTC. Fortuitously, it flew over many of the instruments that are part of the SpanishMeteor and Fireball Network so that accurate measurements of its properties were recorded.We describe these observations and make deductions from them regarding the nature andorigin of the body that gave rise to this fireball. The bolide first became visible at a height of98.3 km, attained its maximum brightness at a height of 26 km and finished at a height of 21.5km. These values are very much in line with other well-known fireballs producing meteorites.Standard calculations based on the meteoroids’ ability to survive in the atmosphere suggesta strength for the remnant that survived to this height of about 14 MPa, similar to those formeteorite-dropping bolides. So far, this fireball looks typical and one might well expect to findmeteorites on the ground in due course. The heliocentric orbit of the meteoroid determinedfrom the observations had a perihelion essentially at the Earth’s orbit and an eccentricityof 0.775, so that the orbit extends far beyond Jupiter, nearly reaching Saturn’s heliocentricdistance and is a typical orbit for a member of the Jupiter family of comets. This is unlike otherbright fireballs, where aphelion is within the asteroidal belt and clearly points to an asteroidalorigin. The orbit is also very similar to the mean orbit of the Omicron Draconid meteor shower,which is an additional pointer to this fireball being of cometary origin. If the parent was indeeda comet, this has implications for the internal structure of comets in that significant-sizednon-icy inclusions must exist there. This is not surprising, but this is probably the first timethat direct evidence has been found showing that this is the case. Further, such chunks can onlybe released through the catastrophic breakup of the nucleus. Remarkably, a candidate for theparent of the Omicron Draconid meteor shower is comet C/1919 Q2 (Metcalf) which suffereda catastrophic breakup in the early decades of the last century.
PB Oxford University Press
SN 0035-8711
SN 1365-2966 (electrónico)
YR 2009
FD 2009
LK http://hdl.handle.net/10272/9326
UL http://hdl.handle.net/10272/9326
LA eng
NO Trigo Rodríguez, J.M., Madiedo Gil, J.M., Williams, I. P., Castro Tirado, A.J., Llorca, J., Vítek, S., Jelinek, M.: "Observations of a very bright fireball and its likely link with comet C/1919 Q2 Metcalf". Monthly Notices of the Royal Astronomical Society. Vol. 394, n. 1, pág. 569–576, (2009). ISSN 0035-8711
DS Repositorio Institucional de la Universidad de Huelva
RD 30 may 2026