No.2 : Plotted by Hashimoto Takema. All meteors plotting.
Meteor outburst in June(Iota Draconids)
A meteor outburst was observed on June 27th in Japan. This is an interim report of meteor outburst for visual observations in Japan on July 6.
I call this meteor outburst "Iota Draconids" for the possition of radiant point. I probably think that Iota Draconids is associated with comet 7P/Pons-Winnecke because of period, radiant and velocity. I know that the comet 7P/Pons-Winnecke orbit is not closed to the Earth orbit recently. but, I think that the display occurred for the reason why the meteoroids which were released when the comet orbit had closed to the Earth orbit had just crossed at the Earth.
Many Japanese people saw the display in spite of rainy season, but it had been a few avarable observations. There are some usuful data as follows.
Observers and Observation site:
HASTA : Hashimoto Takema (Hachioji, Tokyo N35.63 E139.35)
IZUKI : Izumi Kiyoshi (Takayama, Gunma N36.58 E138.97)
ITODA : Ito Daiyu (Mt.Tsukuba, Ibaraki N36.02 E140.13)
NOSKU : Nose Kunio (Nayoro, Hokkaido N44.43 E142.38)
OSAKA : Osada Kazuhiro (Oyama, Shizuoka N35.37 E138.95)
SATKO : Sato Koetsu (Mt.Zaoh, Miyagi N38.13 E140.48)
SAKMI : Sakaguchi Mitsue (Hiroshima, Hiroshima N34.50 E132.67)
SEKTA : Sekiguchi Takashi (Kawagoe, Saitama N35.88 E139.45)
note) According to the Japanese custom, I wrote family name first.
Observation method:
Visual , Plotting
HASTA,IZUKI,ITODA,OSAKA,SATKO,SAKMI
TV ,Single station
NOSKU(28/50mm),SEKTA(28mm)
Observational Data:
<appearance>
Iota
DATE UT Time total Spor. Dra HR Lm CL Dir Obs. Meth. Remarks
---------------------------------------------------------------------------
June 26 16:10-17:10 60 7 7 0 0.0 5.7 4 Z SAKMI V(P)
June 27 11:15-12:15 60 36 11 25 25.0 5.1 2 Z OSAKA V(P)
June 28 11:39-11:49 10 3 1 2 12.0 5.0 2 CrB NOSKU TV(S) *1
11:55-12:45 50 6 4 2 2.4 5.0 3 CrB NOSKU TV(S) *2
15:20-16:20 60 10 10 0 0.0 6.3 3 Oph SAKMI V(P)
16:20-17:20 60 6 6 0 0.0 6.3 2 Oph SAKMI V(P)
June 29 11:00-12:10 70 1 1 0 0.0 5.2 1 Dra IZUKI V(P)
12:15-13:15 60 21 21 0 0.0 5.8 0 Z OSAKA V(P)
12:42-14:15 75 14 14 0 0.0 7.2 0 Dra NOSKU TV(S) *3
13:00-14:20 80 5 5 0 0.0 5.8 0 Lyr SEKTA TV(S)
13:30-15:00 80 11 11 0 0.0 6.2 0 Her SATKO V(P) *4
15:00-16:00 60 17 16 0 0.0 6.3 0 Oph SAKMI V(P)
15:30-17:00 90 12 7 5 3.3 5.1 0 Dra HASTA V(P)
16:00-17:00 60 9 9 0 0.0 6.3 0 Oph SAKMI V(P)
June 30 12:40-13:40 60 1 1 0 0.0 4.8 0 Her ITODA V(P)
13:10-14:00 50 3 3 0 0.0 5.2 1 CrB SATKO V(P)
13:50-14:30 40 2 2 0 0.0 5.1 1 Her ITODA V(P)
14:00-15:00 60 6 6 0 0.0 5.3 0 Her SATKO V(P)
14:00-15:30 90 23 23 0 0.0 5.5 2 Z OSAKA V(P)
July 01 11:30-12:30 60 12 10 2 2.0 5.3 1 Z OSAKA V(P)
12:30-13:30 60 13 11 2 2.0 5.3 2 Z OSAKA V(P)
July 02 12:00-13:15 75 18 17 1 0.8 5.5 1 Z OSAKA V(P)
July 03 16:00-17:00 60 6 6 0 0.0 4.6 0 Dra HASTA V(P)
*1:slightly cloudy, using 28mm lens.
*2:slightly cloudy, using 50mm lens.
*3:18 minits stop observing.
*4:13h45m-55m(10min) stop observing.
<radiant point>
No. YMD(UT) CONST R.A DEC N d Wt Vel Mag HR Obs. Meth.
-----------------------------------------------------------------------------
1. 1998/06/27.49 Iota Dra 221 +51 22 10 4 rS-rR 3.1 25.0 OSAKA V(P)
2. 1998/06/29.68 Iota Dra 229 +50 5 5 1 vS-rS 2.6 3.3 HASTA V(P)
3. 1998/07/01.52 Iota Dra 227 +48 4 5 1 S-rS 2.3 2.0 OSAKA V(P)
Time : Observed time interval
Total: Total number of meteors
Spor.: Number of Sporadic meteors
P-W : Number of Iota Draconids meteors
HR : Hourly rate
Lm : Limiting magnitude of field stars
CL : Cloud coverage
Dir : Observation direction ( Z = Zenith )
Meth.: Method (V = Visual, P = Plotting, TV = TV, S = Single station)
N : Number of using meteors for R.P
d : Diameter (deg)
Vel : Velocity (vS = Very Slow, S = Slow, rS = Rather Slow, M = Moderate
rR = rather Rapid, R = Rapid, vR = Very Rapid)
Mag : Mean magnitude
Magnitude Distribution of Iota Draconids
|Mag| -3 -2 -1 0 1 2 3 4 5 6 |Tatal| Ave | Lm | Obs.
+---+----------------------------------------+-----+-----+-----+-----
(June 27)
|Dra| 0 0 1 1 2 3 9 6 3 - | 25 | 2.9 | 5.1 |OSAKA
|Spo| 0 0 0 0 0 0 4 6 1 - | 11 | 3.7 | 5.1 |OSAKA
(June 29)
|Dra| 0 0 0 0 0 2 3 0 - - | 5 | 2.6 | 5.1 |HASTA
|Spo| 0 0 0 0 1 1 2 3 - - | 7 | 3.0 | 5.1 |HASTA
Velocity Distribution of Iota Draconids
| | rS M rR
+--+----------
|PW| 26 8 3
Time Chart for Iota Draconids on June 27(UT)
(Exclude observation)
10h 11h
15m 20 25 30 35 40 45 50 55 00m 05 10 15
+----+----+----+----+----+----+----+----+----+----+----+----+
S -4 -2 -1 0 -1 1 0 0 1 3 -1-1
(Observation)
11h 12h
15m 20 25 30 35 40 45 50 55 00m 05 10 15
+----+----+----+----+----+----+----+----+----+----+----+----+
3 4 0 1 4 33 3 3 2 5 34 5 4 4 5 312 2 E
3 3 4 -1
Note)Numeric character is magnitude.
S:start
E:end
‚r‚s‚`‚q CHART
No.1 : Plotted by Osada Kazuhiro. All meteors
plotting.
No.2 : Plotted by Hashimoto Takema. All meteors plotting.