Month: July 2017

The Mayas and Eta Aquariids in AD 250-909

From the meteor library An interesting paper has been published about “Evidence of Eta Aquariid Outbursts Recorded in the Classic Maya Hieroglyphic Script Using Orbital Integrations” by J.H. Kinsman and D.J. Asher. The history of Eta Aquariid outbursts has been reconstructed based upon a numerically integrated model of particles released from comet Halley. These calculated outbursts were matched with major events described in the Maya records. It is very likely that the Maya kept track of the Eta Aquariid activity associating outbursts with major events in their society. The complete article can be consulted online:...

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The New Method of estimating ZHR using Radio Meteor Observations

Hirofumi Sugimoto (The Nippon Meteor Society) It has been very difficult to estimate Zenithal Hourly Rate in the case of Radio Meteor Observations, although it is very useful method for catching all meteor activities even if in bad weather or daytime. This research tries to estimate Zenithal Hourly Rate using Radio Meteor Observations. 1. Introduction As a known method for combining all radio meteor observations, H. Ogawa et al.(2001) published a new index that was “Activity Level” Index. Although this index is very useful for catching meteor activity profiles (period, level etc.), it is impossible to compare with visual observations. This research tried to estimate Zenithal Hourly Rate using radio meteor observations. By using this estimated ZHR, it becomes possible to discuss on the same table as visual observations. 2. Method An estimated ZHR is led by steps as following. (1) correcting machine feature such as antenna, receiver, receiving level, etc. and removing sporadic meteors (2) correcting limiting magnitude (3) correcting radian elevation (4) combining all calculated data 2.1. correction machine features This step adopts previous method by H. Ogawa et al.(2001). First step means as same as leading to Activity Level index. Activity level is led by as following formula. A(t) = [ N_obs(t) – N_ave(t) ] / D_ave where, N_obs is the hourly rate of observed meteor echoes. N_ave is the background level past two weeks. N_ave,...

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Meteor Observations July 28, 2017 from California, USA

It was 1 year ago tonight that the July gamma Draconids produced an impressive outburst over Europe. If any such occurrence were to repeat in 2017, it would most likely occur over North America near 6UT. I went out with little anticipation and that is exactly what I saw. Only 2 GDR’s appeared during 2 hours centered on 6UT. I was actually surprised I caught 2 of them! The first one was slightly brighter than Deneb and shot past that star in Cygnus. The second was of 3rd magnitude and shot through the head of Draco. “Shot” may be an incorrect description as both of these meteor were fairly slow. Both evening hours produced 6 meteors each with a nice variety as you can see below. The sky appeared nice, more impressive than the limiting magnitude would indicate. After a short nap, I turned toward the south to view the activity there. Conditions had changed drastically for the worse. it was very hazy with clouds to the south and west. The clouds held back for 30 minutes but soon obscured the sky during the 3rd quarter of the hour. Looks like I’ll need to make a trip to higher elevations if I am to see the SDA’s at their best. ——————————————————- Observer: Robert Lunsford (LUNRO) Date: 17- Jul 28 Mean Solar Long: 125.127 Beginning Time (UT) 0500 Ending Time...

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Meteor Activity Outlook for 29 July-4 August 2017

During this period the moon will reach its first quarter phase on Sunday July 30. At this time the moon will be located 90 degrees east of the sun and will set near midnight local summer time (LST). As the week progresses the waxing gibbous moon will impede upon the morning sky shrinking the window of opportunity to view under dark skies.

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Large asteroidal fireball over Madrid

This stunning fireball overflew Toledo and Madrid on July 27 at 00:35 local time (22:35 Universal Time on July 26). The event was produced by a rock from an asteroid that hit the atmosphere at around 54.000 km/h. The fireball began at a height of about 80 km and ended at an altitude of 45 km. It was recorded in the framework of the SMART Project from the astronomical observatories of Calar Alto (Almería, Spain) and La Hita (Toledo, Spain). The bolide was also detected from other meteor stations operated by the Spanish Meteor Netowk...

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