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Lokalizacja:: Kłodzko JO80IK06AO
Posty: 41732 #2153391
Od: 2013-10-18
| Perseidy 2015
UPCOMING METEOR SHOWERS: AUGUST 2015
One of the most popular meteor showers, the Perseids, is coming. Although this shower has proven to be very dynamic in recent years, (especially in the 1990s, due to the perihelion passage of their parent comet, 109P/Swift-Tuttle in 1992, having orbital period of about 130 years) more recently the meteor activity was mostly concentrated around the “normal” peak, with ZHR around 100 hr-1, and even 2015 activity will basically follow this trend.
Recent IMO observations found that timing of “traditional” broad maximum varied between λsol=139°8 to 140°3, equivalent to 2015 August 13, 01h30m UT to 14h00m UT. Node is at λsol=140°0-140°1.
According to IMO, then the maximum in 2015 is expected to occur on August 13, most likely around 06h30m to 09h00m UT, with ZHR = 100 hr-1.
By the way there are some indications that the Perseids meteor rates in 2015 could be a bit higher than what detected in last few years.
According to Mikhail Maslov, (see here ), in 2015-2017 the Earth will encounter a part of Perseids stream perturbed and shifterd closer to Earth’s orbit by Jupiter gravitation. That will increase meteor rates especially in 2016, while in 2015, being the particles about 0.0045 AU closer to Earth than usual, ZHR should reach about 120 hr-1, with peak at the normal maximum (λsol=140°0).
Jeremie Vuabaillon’s theoretical modelling indicates that dust trail from the comet’s 1862 return should pass closest to the Earth (at about 0.00053 AU distance) at 18h39m UT on August 12th. Activity levels are uncertain, but whatever will happen they should persist for several hours around this potential peak.
Of course, some minor showers will also be active in August, κ-Cygnids and daylight γ-Leonids being the most significant.
Last but not least, don’t forget the great help given by Sporadic Meteors: their rates are very close to annual maximum in August.
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73! Stanisław SP6MLK
Kłodzko JO80IK06AO
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