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(meteorobs) Re: 1997 Perseid max data NM
First, I was wiped out again last night. Clouds just wouldn't move or
dissipate in time. I feel like my father hitting a Daily Double at the
horses with the only ticket he bought. The max night has been my only clear
one; fine with me.
rates for 1997 Aug 11/12, Norman McLeod
511 - 626 UT 1.25 F1.00 LM7.2 26 PER 2 CAP 2 NDA 2 SIA
7 SPO 39 TOT
626 - 726 UT 1.00 F1.00 LM7.3 38 PER 3 CAP 2 NDA 1 NIA
8 SPO 52 TOT
726 - 826 UT 1.00 F1.00 LM7.3 68 PER 1 CAP 1 NDA 1 SDA
1 NIA 1 KCG 7 SPO 80 TOT
826 - 952 UT 1.43 F1.00 LM7.3 74 PER 1 NDA 1 SDA 13 SPO
89 TOT
I continued on until 1014 UT (614 EDT) in rapidly advancing twilight,
seeing 10 more Perseids and 2 sporadics. Twilight meteors seldom have any
value for rate determination due to rapidly changing conditions, especially
this far south where twilight is not so leisurely. From first visible
twilight to sunrise is only about 90 minutes, and the sky has noticeable
changes minute by minute.
I faced south to keep good watch on the Aquarids during the Perseids.
Average magnitude for 206 Perseids seen in sky LM7.0 or better was 2.26.
Wes averaged 2.21 for 344 Perseids, almost exactly the same. But Marco
averaged 3.33 for 387 Perseids. There are big differences in perception not
only in rates but also in magnitudes here.
I recall my long-term Perseid average is more like 2.8m, and sporadics 3.4m.
For 35 sporadics seen this night I averaged 3.26m.
Here are Perseid magnitudes for 3 observers (Norman - Marco - Wes) all seen
under similar conditions:
-7 : 0 - 0 - 1
-5 : 1 - 2 - 0
-4 : 3 - 1 - 3
-3 : 1 - 1 - 3
-2 : 2 - 2 - 4
-1 : 13 - 9 - 6
0 : 28 - 15 - 32
1 : 22 - 22 - 50
2 : 36 - 34 - 91
3 : 35 - 110 - 72
4 : 29 - 104 - 58
5 : 28 - 56 - 22
6 : 8 - 34 - 2
Marco and I are just about identical for meteors down to +2m. Going
fainter, he demolishes me with faint rates 3 and 4 times greater. I haven't
seen anything like this since the days of Bill Gates, who was also very
bottom-heavy in magnitude totals. Most high perceptions have been
top-heavy, with faint rates only equal to mine and sometimes less. A good
example of the latter is Bob Lunsford.
Wes and I are about the same down to 0m, then he doubles me thereafter
except for a little weakness in the faintest meteors. With more experience
in fully dark skies, Wes will improve here. Until I got used to dark skies
year-round, I noticed that my occasional trips out of the city would yield
the expected rates but with magnitudes too bright. Mark Adams had the same
problem in his earliest years. So I am setting aside all my magnitude data
earlier than 1972, and am just using the rates.
Perception for showers vs. sporadics also differs. Bill Gates generally saw
only twice my shower rates but ten times my sporadic rates, with overall
perception 3.8. 50-70/hr just sporadics was typical for Gates -- one hour
he exploded with a 104 ! That hour I saw 12 sporadics; there wasn't much
else for me to do that hour but count what Gates was seeing. He ripped off
a string of 21 meteors in one 5-minute period in which I saw nothing at all.
We spent a lot of time studying him as well as his observing results. In
the current period, Wes has 3-4X my sporadic rates while Marco has 4-5X.
Norman
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