Hi all. I just returned from a couple of hours of observing at Skyline Drive. For me, it was the best Perseid show in many years. I arrived at 2:30 and began observing at 2:40. I forgot to take note of the limiting magnitude, but the sky was very clear and dark (for a change this summer) so I’m sure it was at least 6.5 and maybe 7+. I made six 20-minute counts (time below is given in MDT, accurate to 1 sec.; P=Perseids, N=Non-Perseids): 2:40:30 – 3:00:30 P: 23 N: 5 3:10:00 – 3:30:00 P: 30 N: 4 3:37:00 – 3:57:00 P: 30 N: 5 4:00:00 – 4:20:00 P: 37 N: 5 4:23:00 – 4:43:00 P: 26 N: 2 4:46:30 – 5:06:30 P: 37 N: 1 Total: 120 min. P: 183 N: 22 About one-third of the Perseids ranged in brightness from magnitude 1 to -1, with these brighter meteors usually leaving trails lasting up to five seconds. I also noticed a spike in activity from about 3:15 to 3:20. In about five minutes’ time I saw 10 or 12 Perseids, with four of them arriving in as many seconds. I also noticed something unusual about the non-Perseids. I haven’t called them “sporadic” because just over half of them seemed to come from a point in Pegasus. These 12 were all about the same brightness, perhaps magnitude 2 or 3, and a noticeably slower than the Perseids. I centered my observations on the region around M31 and M33, and most of the unusual meteors that I saw were moving opposite to the Perseids in that part of the sky. I’m positive this isn’t coincidental. I’m too tired to research now, but if any of you know of minor showers that fit the meteors I observed, please let me know. Kim Kim A. Hyatt Architect P.O. Box 124 Mt. Pleasant, Utah 84647 Tel: 435.462.9207 Fax: 435.462.5013 Mobile: 801.631.5228 kimharch@cut.net Architectural Design ▪ Historic Preservation No virus found in this outgoing message. Checked by AVG. Version: 7.5.524 / Virus Database: 270.6.0/1604 - Release Date: 8/11/2008 5:50 AM
--- On Tue, 8/12/08, Kim A. Hyatt <kimharch@cut.net> wrote:
I’m too tired to research now, but if any of you know of minor showers that fit the meteors I observed, please let me know.
Kim
Kim: I checked my IMO discussion yahoo discussion list and it lists the Kappa Cygnids as active this week. I've included the main text of this weeks report. DT The following showers are expected to be active this week: The Kappa Cygnids (KCG) are active from a wide radiant located at 18:56 (284) +58. This position is located in southern Draco, five degrees northwest of the fourth magnitude star Kappa Cygni. As seen from the northern hemisphere, current rates would be near one shower member per hour. With an entry velocity of 25 km/sec. most of these meteors will appear to travel slower than average. The radiant is best placed near 2300 Local Daylight Time (11pm LDT) when it lies nearly overhead for much of the Northern Hemisphere. Due to its high northern declination this activity is not well seen from the Southern Hemisphere. Alpha Capricornid (CAP) activity is nearly over for 2008. A few leftover shower members may still be see from a wide radiant located at 21:12 (318) -06. This position lies in western Aquarius, four degrees west of the third magnitude star Sadalsuud (Beta Aquarii). The radiant is best placed near 0100 local daylight time (LDT), when it lies on the meridian and is highest in the sky. Current rates would be less than one per hour no matter your location. Don't confuse these meteors with the nearby antihelion meteors, which have a radiant just to the east. Both radiants need to be in your field of view to properly sort these meteors. With an entry velocity of 23 km/sec., most activity from this radiant would be slow, a bit slower than the antihelions. This radiant is well seen except for far northern latitudes where it remains twilight all night long and the radiant does not rise as high into their sky. The large Antihelion (ANT) radiant is now centered at 22:00 (330) -10. This area of the sky lies on the Capricornus/Aquarius border, ten degrees south of the third magnitude star Sadalmelik (Alpha Aquarii). Actually any meteor from eastern Capricornus as well as western Aquarius, could be a candidate for this shower. This radiant is best placed near 0200 LDT when it lies on the meridian and is highest in the sky. Rates at this time should be near two for northern observers and three for observers south of the equator. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of medium-slow speed. The Delta Aquariids (SDA) are still active from a radiant at 23:16 (349) -13. This position lies in southern Aquarius, five degrees east of the third magnitude star Delta Aquarii. The radiant is best placed near 0300 LDT, when it lies highest in the sky. Current rates would range from one to two shower members per hour, depending on your latitude. With an entry velocity of 41 km/sec., most activity from this radiant would be of average velocities. These meteors tend to be faint so the darkest skies are necessary in order to see this shower well. The Perseids (PER) peak on Tuesday morning August 12 with average hourly rates expected near one per minute. This weekend viewers in the northern hemisphere should see 10-20 Perseids per hour during the dark morning hours after the moon has set. The current radiant position lies at 03:00 (045) +57, which is located in extreme northwestern Perseus, four degrees north of the third magnitude star Gamma Persei. The radiant is well placed for those in the northern hemisphere during the last few hours before dawn. Due to the high northern declination (celestial latitude) of the radiant, rates seen from the Southern Hemisphere are very low when compared to those seen north of the equator. At 59 km/sec., Perseid meteors are swift, often exhibiting persistent trains. More details on viewing the Perseid meteor shower are available at: http://www.amsmeteors.org/showers.html#PER As seen from the mid-northern hemisphere (45N) the Sporadic rates are becoming more active. One would expect to see approximately twelve random meteors during the last hour before dawn from rural observing sites and two per hour during the evening hours. As seen from the mid-southern hemisphere (45S) morning rates would be near ten per hour as seen from rural observing sites and two per hour during the evening hours. Locations between these two extremes would see activity between the listed figures. Moonlight reduces sporadic activity during the evening hours this week. The table below presents a summary of the expected activity this week. Rates and positions are exact for Saturday night/Sunday morning but may be used all week. Kappa Cygnids (KCG) 18:56 (284) +58 Velocity - 25km/sec. Northern Hemisphere Hourly Rates - 1 Southern Hemisphere Hourly Rates -<1 Alpha Capricornids (CAP) 21:12 (318) -06 Velocity - 23km/sec. Northern Hemisphere Hourly Rates - <1 Southern Hemisphere Hourly Rates -<1 Antihelion (ANT) 22:00 (330) -10 Velocity - 30km/sec. Northern Hemisphere Hourly Rates - 2 Southern Hemisphere Hourly Rates - 3 Delta Aquariids (SDA) 23:16 (349) -13 Velocity 41km/sec. Northern Hemisphere Hourly Rates - 1 Southern Hemisphere Hourly Rates - 2 Perseid (PER) 03:00 (045) +57 Velocity - 59km/sec. Northern Hemisphere Hourly Rates - 15 Southern Hemisphere Hourly Rates - 5 Clear Skies! Robert Lunsford International Meteor Organization
Time: 2008 August 12 0400-1100 UT.(Monday night MDT) Location: Puddle Valley in west desert. equiptment: 10x50 binoculars and unaided eyes conditions: Gibbous moon sets at 2 am MDT clear, calm. Warm early droping to the 40's at dawn. Transparency was hazy with the bright moon but improved to very good by morning astro twilight. Main attraction was the Perseid meteor shower but the night was dark enough for some stunning deep sky views with 10x50 binoculars. The Helix ngc7293 was huge and easily held with direct vision. ngc3077 the companion to M81/M82 was easy. ngc6992,6995 the eastern part of the Veil Nebula jumped right out. Nice open clusters ngc1528 in PER and ngc663 and Stock 2 in CAS. Also visited the usual suspects, M13,M92,M11,M31 etc, M33, M27. The Perseids were entertaining but not stunning. At midnight I was seeing as many sporatics as shower members. Things picked up as the night wore on to an estimated 4 per minute at twilight. As Orion rose up the zodiacal light was visable through the ecliptic from Gemini to Taurus. A very good night out. DT
Excellent report Kim. As usual I'm kicking myself for thinking the peak was tonight instead of last night. I did spot one very bright Perseid last evening approx 10:30 in very light polluted skies here in happy valley, so I wasn't totally skunked... ;o) --- On Tue, 8/12/08, Kim A. Hyatt <kimharch@cut.net> wrote:
From: Kim A. Hyatt <kimharch@cut.net> Subject: [Utah-astronomy] Perseids To: "'Utah Astronomy'" <utah-astronomy@mailman.xmission.com> Date: Tuesday, August 12, 2008, 6:11 AM Hi all. I just returned from a couple of hours of observing at Skyline Drive. For me, it was the best Perseid show in many years. I arrived at 2:30 and began observing at 2:40. I forgot to take note of the limiting magnitude, but the sky was very clear and dark (for a change this summer) so I’m sure it was at least 6.5 and maybe 7+. I made six 20-minute counts (time below is given in MDT, accurate to 1 sec.; P=Perseids, N=Non-Perseids):
2:40:30 – 3:00:30 P: 23 N: 5
3:10:00 – 3:30:00 P: 30 N: 4
3:37:00 – 3:57:00 P: 30 N: 5
4:00:00 – 4:20:00 P: 37 N: 5
4:23:00 – 4:43:00 P: 26 N: 2
4:46:30 – 5:06:30 P: 37 N: 1
Total: 120 min. P: 183 N: 22
About one-third of the Perseids ranged in brightness from magnitude 1 to -1, with these brighter meteors usually leaving trails lasting up to five seconds. I also noticed a spike in activity from about 3:15 to 3:20. In about five minutes’ time I saw 10 or 12 Perseids, with four of them arriving in as many seconds. I also noticed something unusual about the non-Perseids. I haven’t called them “sporadic” because just over half of them seemed to come from a point in Pegasus. These 12 were all about the same brightness, perhaps magnitude 2 or 3, and a noticeably slower than the Perseids. I centered my observations on the region around M31 and M33, and most of the unusual meteors that I saw were moving opposite to the Perseids in that part of the sky. I’m positive this isn’t coincidental. I’m too tired to research now, but if any of you know of minor showers that fit the meteors I observed, please let me know.
Kim
Kim A. Hyatt
Architect
P.O. Box 124
Mt. Pleasant, Utah 84647
Tel: 435.462.9207 Fax: 435.462.5013 Mobile: 801.631.5228
kimharch@cut.net
Architectural Design ▪ Historic Preservation
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