Pi Puppids
Encyclopedia
The Pi Puppids are a meteor shower
associated with the comet
26P/Grigg-Skjellerup
.
The meteor
stream was viewable around April 23 but only in years around the parent comet's perihelion date, the last being in 2003. However, as the planet Jupiter
has now perturbed the comet's perihelion to beyond Earth
's orbit it is uncertain how strong the shower will be, if at all, at the next opportunity in 2008.
The Pi Puppids get their name because their radiant
appears to lie in the constellation
Puppis
, at around Right ascension
112 degrees and Declination
−45 degrees. This made them only visible to southern observers.
They were discovered in 1972 and have been observed about every 5 years - at each perihelion passage of the comet - but often at very low rates per hour.
Meteor shower
A meteor shower is a celestial event in which a number of meteors are observed to radiate from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth's atmosphere at extremely high speeds on parallel trajectories. Most meteors are smaller...
associated with the comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
26P/Grigg-Skjellerup
26P/Grigg-Skjellerup
Comet Grigg–Skjellerup is a periodic comet.Discovered in 1902 by John Grigg of New Zealand, and rediscovered in its next appearance in 1922 by John Francis Skjellerup, an Australian then living and working for about two decades in South Africa where he was a founder member of the Astronomical...
.
The meteor
METEOR
METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...
stream was viewable around April 23 but only in years around the parent comet's perihelion date, the last being in 2003. However, as the planet Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
has now perturbed the comet's perihelion to beyond Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
's orbit it is uncertain how strong the shower will be, if at all, at the next opportunity in 2008.
The Pi Puppids get their name because their radiant
Radiant (meteor shower)
The radiant or apparent radiant of a meteor shower is the point in the sky, from which meteors appear to originate. The Perseids, for example, are meteors which appear to come from a point within the constellation of Perseus....
appears to lie in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
Puppis
Puppis
Puppis is a constellation in the southern sky. Its name is the Latin word for the poop deck of a ship, and Puppis represents the deck of the ship and its deckhouses...
, at around Right ascension
Right ascension
Right ascension is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination.-Explanation:...
112 degrees and Declination
Declination
In astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and...
−45 degrees. This made them only visible to southern observers.
They were discovered in 1972 and have been observed about every 5 years - at each perihelion passage of the comet - but often at very low rates per hour.