(meteorobs) Lions and Lambdas
Bruce McCurdy
bmccurdy at telusplanet.net
Tue Nov 27 05:48:09 EST 2007
Last weekend my recent string of bad luck for observing the peaks of
meteor showers continued, as the best night for the Leonids, Saturday/Sunday
the 17/18, was totally socked in throughout northern Alberta. However the
system began to break up during the next afternoon. On my Sunday night
Observatory shift (ended early by another band of cloud), I got a quick look
at Comet Holmes "occulting" Mirfak through our club's 7-inch Astrophysics
Starfire refractor; at 73x the thing filled about half the 1.2° field of the
22mm Nagler. So many meteoroids, so little time ...
Alister (correctly! as usual) predicted clearing skies by around
midnight, but was unable to join me. So I headed off to my primary dark
site at Beaver Hills Dark Sky Preserve -- a pleasant change, having observed
meteors from at least eight different sites this year. With the waxing
gibbous Moon still hovering above the western horizon and frequent reminders
that Novembrrr winds do indeed bite, I wasn't too surprised to find myself
alone in the parking lot at the end of the Universe. There wasn't a sound to
be heard from nature, and I wasn't in the mood for forward scatter meteor
observations (there's quite enough static in my life just now, thank you).
With no observing etiquette concerns, I turned on the car radio and enjoyed
a wonderfully eclectic selection of great tunes on CKUA's "Overnight" show.
I whiled away the overnight hours in contented solitude: just me, meteors,
and music.
And a fine session it was. In four hours Teff I totalled 65 meteors,
including 25 Leonids, a decent number for ~30 hours after maximum. 10 of
these were of zeroeth magnitude or brighter, and the average Leonid was an
impressive mag +1.3, with about half leaving persistent trains. The Taurids
were still weakly in evidence, more than six weeks after my first
observations of this very broad stream back on Oct. 7. But the (shooting)
stars of the show were the lambda Orionids, which, as described in my alert
to meteorobs of Nov. 19, featured two brief outbursts and a very surprising
9 meteors in one hour. In my previous report I mistakenly said the first six
lambda Orionids occurred in a 15-minute interval; upon transcription of my
"LOR data" it was actually 23 minutes. After a lull of 35 minutes I got
three more in under a minute, including a near-simultaneous pair very near
the radiant. Two more singletons followed at about half-hour intervals.
Almost all of these meteors were dropping in the vicinity of Orion, as the
Hunter kept shooting himself in the foot, hitting himself below the belt, or
smacking himself upside the head. Finally he got his sights aligned and
launched the last arrow, a lingering first-magnitude beauty, into the
charging head of his old nemesis, Taurus. This was the coup de grace in what
has seemed to my amused imagination, an ongoing battle between the two
mythical enemies over the past few weeks.
As is always the case I enjoyed the opportunity to do some naked eye
astronomy during my meteor count. Mars near its stationary point towered
high in the south, transforming the Winter Triangle of Procyon, Betelgeuse
and Sirius into a temporary Winter Diamond. Venus was very distracting as it
rose through the swaying branches of an evergreen tree, the very definition
of a fireball occasionally flashing in my peripheral vision. Comet Holmes
was very difficult to resolve in the glare of Mirfak, it just looked like a
halo around the star, except -- wait a minute -- why is that halo
off-centre?
At the end of the night I had a long look with my 15x70 binoculars, and
Holmes appeared sensibly larger than the Moon. The comet was contained
within the sprawling alpha Persei Association, but had itself captured
Mirfak which gleamed right through one edge of it, an unforgettable sight.
Reluctantly I lowered my binos and headed for home, my soul once again
rejuvenated by a fabulous night under the stars.
Bruce
*****
Observer: Bruce McCurdy MCCBR
Date: 2007 November 19, 0730 - 1200 UT; Teff = 4.0 hours
Location: Beaver Hills Dark Sky Preserve (Blackfoot) IMO location code 51128
53°32'12" N, 112° 46m 48s W, elevation 711 metres
Limiting magnitude: 5.7 until moonset, 6.0 to 6.2 thereafter (SQM = 20.5 to
21.3)
Direction faced: southeast towards Gemini, 60°; then south towards Orion,
50°
Method: Visual; microcassette recorder and talking watch
-----
Active radiants:
Northern Taurids (NTA) 04:12 (063) +24
Southern Taurids (STA) 04:08 (062) +16
Iota Aurigids (IAU) 05:00 (075) +30
Lambda Orionids (LOR) 05:28 (082) +15
Alpha Monocerotids (AMO) 07:48 (117) +01
Leonids (LEO) 10:12 (153) +22
-----
07:30-08:35; clear; LM = 5.7 to 6.0; SE 60°; Teff = 1.0 hour
Time type mag comment
---------------------------------------
07:30 start LM = 5.7, SQM = 20.8
07:31 SPO +4
07:39 STA +3
07:39 LEO +2 ~ (= persistent train) 0.5 s
07:49 LEO 0
07:50 SPO +3 swift
07:55 LEO +2 ~ 0.5 s
07:55 STA +2
07:55 SPO +4
08:00 IAU +2
08:02 SPO +3
08:04 IAU +1
08:05 LEO 0 ~ 1.5 s, pure white, "broadened out like a contrail and
faded into its width"
08:10 STA 0 near radiant, 1 s. meteor, 2° path
[08:11 moonset]
[08:15-08:20 break 5 min.]
08:24 LEO +5 LM = 6.0, SQM = 21.1
08:34 LEO +4
***
0 NTA
3 STA: 0, +2, +3
2 IAU: +1, +2
0 LOR
0 AMO
6 LEO: 0(2), +2(2), +4, +5
4 SPO: +3(2), +4(2)
Total meteors: fifteen
*****
08:35-09:45; clear; LM = 6.0 to 6.1; S 50°; Teff = 1.0 hour
Time type mag comment
---------------------------------------
08:38 LEO +3
08:39 SPO +3 "majestic"
08:40 SPO +2
08:40 IAU +3
[08:42-08:52 break 10 min.]
08:54 SPO -3 orange, v. slow, 2-3 s duration, 8-10° trail, thru
Orion
09:03 SPO +3 brief wake
09:08 LEO +3
09:13 LEO +1 ~ 0.5 s LM = 6.1, SQM = 21.2
09:16 SPO -1 "brighter and orangier than Mars, even the train
seemed orange"
09:21 LOR +2 slow, near radiant
09:21 LOR +4 a little faster, a little further from the radiant
09:24 LOR +1 very slow, near the radiant, brief wake
09:27 SPO +2 ~ 0.5 s
09:30 LOR 0 faded and came back, ~ 0.5 s
09:32 LEO -1 ~ 1.5 s
09:35 SPO +3
09:36 AMO +3
09:42 LOR +4 "weird, like a double or two edges of one meteor"
09:44 LOR 0 white, 10° long near horizon, 1 s meteor, ~ 1 s train
***
0 NTA
0 STA
1 IAU: +3
6 LOR: 0(2), +1, +2, +4(2)
1 AMO: +3
4 LEO: -1, +1, +3(2)
7 SPO: -3, -1, +2(2), +3(3)
Total meteors: nineteen
*****
09:50-10:50; clear; LM = 6.1; S 50°; Teff = 1.0 hour
Time type mag comment
---------------------------------------
[09:45-09:50 break 5 min.]
09:52 LEO -1 ~ 0.5 s LM = 6.1, SQM = 21.2
10:03 LEO +1
10:03 LEO +1 ~ 0.5 s
10:05 SPO +3
10:05 LEO 0 ~ 1.5 s
10:07 LEO +4
10:19 LOR 0
10:20 LOR +3 > both short, near radiant
10:20 LOR +5 > ~ 1 s interval between them
10:26 LEO -1 ~ 1 s
10:30 NTA +2 slow, 1 s meteor
10:32 STA +4
10:32 NTA +3
10:36 LEO +3 near radiant
10:36 LEO +3
10:42 SPO +3
10:43 NTA +4
10:43 IAU +4 slow, >1 s meteor
10:48 LOR +3
***
3 NTA: +2, +3, +4
1 STA: +4
1 IAU: +4
4 LOR: 0, +3(2), +5
0 AMO
8 LEO: -1(2), 0, +1(2), +3(2), +4
2 SPO: +3(2)
Total meteors: nineteen
*****
11:00-12:00; clear; LM = 6.2; S 60°; Teff = 1.0 hour
Time type mag comment
---------------------------------------
[10:50-11:00 break 10 min.] LM = 6.2. SQM = 21.3
11:02 AMO 0 white, slow, near radiant, ~ 0.5 s
11:09 LEO 0 near radiant
11:11 SPO +3
11:20 LEO +4
11:26 LOR +1 1 s meteor, ~ 1 s train, into Taurus ("Orion shoots
back!")
11:28 LEO -2 ~ 1 s, "Mars colour but brighter"
11:31 LEO -1 ~ 1.5 s
11:33 SPO +3
11:50 LEO -1 ~ 0.5 s
11:50 LEO +3 no train
11:51 SPO +4
11:59 LEO +1
12:00 end
***
0 NTA
0 STA
0 IAU
1 LOR: +1
1 AMO: 0
7 LEO: -2, -1(2), 0, +1, +3, +4
3 SPO: +3(2), +4
Total meteors: twelve
*****
Observing summary
Teff = 4.0 hours
-------------------------------
3 NTA: +2, +3, +4 [avg. = +3.0]
4 STA: 0, +2, +3, +4 [avg. = +2.2]
4 IAU: +1, +2, +3, +4 [avg. = +2.5]
11 LOR: 0(3), +1(2), +2, +3(2), +4(2), +5 [avg. = +2.1]
2 AMO: 0, +3 [avg. = +1.5]
25 LEO: -2, -1(5), 0(4), +1(4), +2(2) +3(5), +4(3), +5 [avg. = +1.3]
16 SPO: -3, -1, +2(2), +3(9), +4(3) [avg. = +2.4]
Total meteors: sixty-five
*****
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