* Astronomy

Blobrana · L

Orionid meteor shower

Blobrana · L

Orionid Meteor Shower peak at 05:00 UT, 21st October 2016. (?)

Blobrana · L

Orionids meteor maximum in the constellation Orion at 01:00 UT, 22nd October 2013

Blobrana · L

Title: PF191012 Myszyniec - highest Orionid meteor ever recorded
Authors: A. Olech, P. Zoladek, M. Wisniewski, K. Fietkiewicz, M. Maciejewski, Z. Tyminski, T. Krzyzanowski, M. Krasnowski, M. Kwinta, M. Myszkiewicz, K. Polakowski, P. Zareba

On the night of Oct 18/19, 2012 at 00:23 UT a -14.7 mag Orionid fireball occurred over northeastern Poland. The precise orbit and atmospheric trajectory of the event is presented, based on the data collected by five video and one photographic Polish Fireball Network (PFN) stations. The beginning height of the meteor is 168.4 ± 0.6 km which makes the PF191012 Myszyniec fireball the highest ever observed, well documented meteor not belonging to the Leonid shower. The ablation became the dominant source of light of the meteor at a height of around 115 km. The thermalisation of sputtered particles is suggested to be the source of radiation above that value. The transition height of 115 km is 10-15 km below the transition heights derived for Leonids and it might suggest that the material of Leonids should be more fragile and have probably smaller bulk density than in case of Orionids.

Read more (1483kb, PDF)

Blobrana · L

Title: Resonant Behaviour of Comet Halley and the Orionid Stream
Authors: Aswin Sekhar, David J Asher

Comet 1P/Halley has the unique distinction of having a very comprehensive set of observational records for almost every perihelion passage from 240 B.C. This has helped to constrain theoretical models pertaining to its orbital evolution. Many previous works have shown the active role of mean motion resonances in the evolution of various meteoroid streams. Here we look at how various resonances, especially the 1:6 and 2:13 mean motion resonances with Jupiter, affect comet 1P/Halley and thereby enhance the chances of meteoroid particles getting trapped in resonance, leading to meteor outbursts in some particular years. Comet Halley itself librated in the 2:13 resonance from 240 B.C. to 1700 A.D. and in the 1:6 resonance from 1404 B.C. to 690 B.C., while stream particles can survive for timescales of the order of 10,000 years and 1,000 years in the 1:6 and 2:13 resonances respectively. This determines the long term dynamical evolution and stream structure, influencing the occurrence of Orionid outbursts. Specifically we are able to correlate the occurrence of enhanced meteor phenomena seen between 1436-1440, 1933-1938 & 2006-2010 with the 1:6 resonance and meteor outbursts in 1916 & 1993 with the 2:13 resonance. Ancient as well as modern observational records agree with these theoretical simulations to a very good degree.

Read more (883kb, PDF)

Blobrana · L

Revisiting an old friend

Comet Halley, the originator of the Orionids meteor shower that lit up our skies last month - as they do every October - is seen here up close by ESA's Giotto probe as it flew past the famous comet on 13-14 March 1986. Giotto was ESA's first deep-space mission. It swept within 600 km of Halley, obtaining the first close-up images of a comet.
Read more

Blobrana · L

Halley's Comet Brings Meteor Shower 2012 this Weekend

Spoiler

Blobrana · L

RE: Orionid meteor shower 2012

Blobrana · L

Orionid meteor shower

Blobrana · L

Orionids meteor shower to be October treat for stargazers

Weather conditions permitting, the Orionids, a meteor shower that is the product of leftover bits from the famed Halley's Comet, should dazzle stargazers in October, state astronomers said Sunday.
In its astronomical diary for October, PAGASA hinted fireballs may be seen during the meteor shower since the Orionids are very fast.
Source