(meteorobs) Obs: 11/12 Aug 2009

[pmartsching at mchsi.com]

12 Aug 2009 02:45-09:50 (with long break 05:45-06:30) UT 
(CDST 11/12 Aug 09:45 pm - 04:50 am; break 12:45-01:30 am)

Paul Martsching
McFarland Park 4 miles NE of Ames, Story County, Iowa, USA
Long: 93 deg 34 min W  Lat: 42 deg 05 min N  Elevation: ~310 meters
Method: Visual; paper, pencil and talking clock; black umbrella to block waning gibbous Moon

Observed showers:
Antihelion: none seen
Capricornids: none seen
Kappa Cygnids: two seen before break; none seen after break
Perseids
Delta Aquarids: only mentioned if any seen during that hour
Sporadics

Hourly summaries:

02:45-03:45 UT (CDST 09:45-10:45); 70 degrees F; dew point 66 degrees F; wind - calm; clear; LM ~5.5; a bit of twilight in NW at 02:45; Moon rise ~03:40; facing NNW 45 degrees; total teff 1.0 hour
Kappa Cygnid: one: +2
Perseids: eleven: -3; 0(3); +1(2); +2; +3(4)
Sporadics: two: -1; +3
Total meteors: fourteen

03:45-04:45 UT (CDST 10:45-11:45); 67 deg F; dew point 65 deg F; wind - calm; LM ~5.0; 20% cloud cover; facing NNW 45 deg; total teff 1.0 hour
Kappa Cygnids: none
Perseids: four: 0; +1(2); +2
Sporadics: two: -1; +3
Total meteors: six

04:45-05:45 UT (CDST 11:45pm - 12:45 am); 67 deg F; dew point 66 deg F; wind - calm; LM 4.75; Moon lit haze between clouds;  25% cloud cover; facing NNW 45 deg; total teff 1.0 hour
Kappa Cygnid: one: +2
Perseids: nine: 0(2); +1; +2(4); +3(2)
Sporadic: one: +3
Total meteors: eleven

Long break 05:45-06:30 UT (CDST 12:45-01:30 am) 
More and thicker clouds moving in from the SW.  Went home and checked several weather web sites.  According to all the web sites (infrared/watervapor/multicolored) the clouds did not exist!  I went back outside and noticed the clouds seemed to be thinning to the West.  So I went back out to observe.  The northern sky cleared by the time I got set up again.

06:30-07:30 UT (01:30-02:30 am CDST); 67 deg F; dew pt 64 deg F; wind calm; clear; LM ~5.0; facing NNW 45 deg; total teff 1.0 hour
Delta Aquarid: one: +2
Kappa Cygnid: none
Perseids: fourteen: -3; -2; -1; 0(3); +1; +2(2); +3(4); +4
Sporadics: two: +1; +3
Total meteors: seventeen

07:30-08:30 UT (02:30-03:30 am CDST); 66 deg F; dew pt 64 deg F; wind - calm; clear; LM ~5.0; facing NNW 45 deg; total teff 1.0 hour
Kappa Cygnid: none
Delta Aquarid: one: +3
Perseids: 45: -5; -3; -2; -1(9); 0(9); +1(8); +2(9); +3(3); +4(4)
Sporadics: one: +3
Total meteors: forty-seven

08:30-09:30 UT (03:30-04:30 am CDST): 65 deg F; dew pt 63 deg F; wind - calm; clear; LM ~4.9; a little fog; facing NNW 45 deg; total teff 1.0 hour
Kappa Cygnid: none
Perseids: 35: -4; -3; -2(4); -1(5); 0(3); +1(4); +2(9); +3(7); +4
Sporadics: seven: +3(5); +4(2)
Total meteors: forty-two

Last 20 minutes:
09:30-09:50 UT (04:30-04:50 CDST); 62 deg F; dew pt 62 deg F; wind - calm; LM ~4.6; twilight well underway in NE; a little fog; facing NNW 45 deg; total teff 1.0 hour
Kappa Cygnid: none
Perseids: ten: -3; -1; -1; 0(4); +1; +2; +3
Sporadic: one: +2
Total meteors: eleven: (0.33 hour/20 minutes)

I was extremely tired during last 20 minutes.  There was some fog on the way home.

Perseids by 15 minute time periods:

P = Perseid; S = Sporadic; K = Kappa Cygnid; D = D Aquarid
02:45-03:00   1 P   1 S           LM 5.5
03:00-03:15   3 P   1 K          LM 5.6
03:15-03:30   5 P                   LM 5.6
03:30-03:45   2 P   1 S           LM 5.5
03:45-04:00   1 P                   LM 5.3
04:00-04:15   (no meteors)     LM 5.1
04:15-04:30   2 P   1 S           LM 5.0; 10% cloud cover
04:30-04:45   1 P   1 S           LM 4.8; 30% cloud cover
04:45-05:00   0 P   1 K          LM 4.8; 20% cloud cover
05:00-05:15   1 P                   LM 4.7; 10% cloud cover
05:15-05:30   5 P   1 S            LM 4.7; 10% cloud cover
05:30-05:45   3 P                   LM 4.6; 50% cloud cover
Break because of increasing cloud cover
06:30-06:45   5 P                   LM 5.0; clear
06:45-07:00   4 P   1 D  1 S   LM 5.0; clear
07:00-07:15   2 P                   LM 5.0; clear
07:15-07:30   3 P   1 S           LM 5.0; clear
07:30-07:45   12 P                 LM 5.0; clear
07:45-08:00   15 P 1 D  1 S   LM 5.0; clear       *****rates high 07:30 - 08:15*****
08:00-08:15   12 P                 LM 5.0; clear
08:15-08:30   6 P                   LM 4.9; clear
08:30-08:45   5 P  2 S            LM 4.9; clear
08:45-09:00   9 P  1 S            LM 4.9; clear
09:00-09:15   11 P 2 S           LM 4.9; clear
09:15-09:30   10 P 2 S           LM 4.8; clear; a little fog
09:30-09:45   8 P 1 S              LM 4.6; clear; twilight; a little fog
(did not include last 5 minutes of observing 9:45-09:50 - so interval would = 15 minutes for comparison.)

A very good show!  Forty-five Perseids in an hour with a waning gibbous Moon up and not far from the radiant isn't too bad!