Outburst of Giacobinids in 1998.
Generally speaking of Japanese observation until this time, Giacobinids activity was almost limited at maximum day. But, Giacobinid shower activity had already started a few days before maximum day in this year. Some observers witnessed its meteors and detected its radiant points.
Giacobinids was outburst on October 8. According to the analysis of rate of 10 minutes interval, It seems that The peak of Giacobinids was around 13h10m(UT) and lambda = 195.075. The activity was about HR=50 (ZHR=400 by NMS).
Giacobinids activity finished on October 11.
Observers :
Hashimoto Takema : HASTA
Ito Osamu : ITOOS
Kondo Hideki : KONHI
Osada Kazuhiro : OSAKA
Maeda Koji : MAEKO
Numazawa Shigemi : NUMSH
Sakaguchi Mitsue : SAKMI
Sekiguchi Takashi : SEKTA
Tonomura Yasuhiro : TONYA
Observation Period :
October 2-8, 1998.
Observation site:
HASTA : Mt.Momokura, Ohtsuki, Yamanashi, Japan E:139.0 deg , N:35.6 deg
Hachioji, Tokyo, Japan E:139.4 deg , N:35.6 deg
KONHI : Narusawa, Yamanashi, Japan E:138.8 deg , N:35.5 deg
MAEKO : Kiyotake, Miyazaki, Miyazaki, Japan ,
NUMSH : Mt.Akagi, Gunma, Japan E:139.2 deg , N:36.4 deg
OSAKA : Oyama, Shizuoka, Japan E:139.0 deg , N:35.3 deg
SAKMI : Higashi-Hiroshima, Hiroshima, Japan E:132.6 deg , N:34.5 deg
SEKTA : Asahi, Kawagoe, Saitama, Japan ,
TONYA : Mekawa, Miyagi, Japan ,
Observation method:
visual , plotting
counting (only Maximum day)
Observational Data:
DATE UT JST TIME aM Spo Gia Lm CL Dir Obs. Meth.
----------------------------------------------------------------------
Oct/1998
02 10:30-11:30 19:30-20:30 60 6 4 2 5.3 0 Dra HASTA V(P)
02 11:30-12:30 20:30-21:30 60 4 4 0 5.1 0 Dra HASTA V(P)
03 11:00-12:00 20:00-21:00 60 9 8 0 5.0 2 Z OSAKA V(P)
03 12:00-13:00 21:00-22:00 60 10 10 0 5.0 1 Z OSAKA V(P)
03 12:30-13:30 21:30-22:30 60 6 6 0 4.6 0 Cyg HASTA V(P)
04 10:00-11:00 19:00-20:00 60 8 7 1 4.8 2 Z OSAKA V(P)
04 11:00-12:00 20:00-21:00 60 7 5 2 5.0 2 Z OSAKA V(P)
04 12:00-13:00 21:00-22:00 60 9 7 2 5.2 1 Z OSAKA V(P)
05 10:00-10:50 19:00-19:50 50 10 6 4 5.1 0 Dra SAKMI V(P)
06 09:15-10:15 18:15-19:15 60 8 6 2 5.0 1 Z OSAKA V(P)
06 10:15-11:30 19:15-20:30 75 12 8 4 5.0 2 Z OSAKA V(P)
07 11:45-12:47 20:45-21:47 53 3 3 0 4.3 1 Cep MAEKO V(P)
07 12:05-12-40 21:05-21:40 35 10 5 5 5.1 3 Dra SAKMI V(P)
07 12:51-14:00 21:51-23:00 61 2 2 0 4.8 0 Cep MAEKO V(P)
Maximum activity was reported as follows
09 10:15-11:00 19:15-20:00 75 4 1 3 10.0 0 Dra TONYA T(P)
09 10:30-11:30 19:30-20:30 60 17 15 2 5.2 2 Z OSAKA V(P)
09 11:00-12:00 20:00-21:00 60 3 0 3 9.0 0 Dra TONYA T(P)
09 12:00-13:00 21:00-22:00 60 15 9 2 4.8 3 Dra SAKMI V(P)
10 12:45-14:00 21:45-23:00 75 21 14 1 5.5 1 Z OSAKA V(P)
11 10:00-11:00 19:00-20:00 60 4 0 2 6.0 0 Peg TONYA V(P)
11 11:00-12:00 20:30-21:00 60 5 1 1 6.0 0 Peg TONYA V(P)
TIME : Observed time interval
Total : Total number of meteors
Spo : Sporadic meteors
Gia : Giacobinids
Lm : Limiting magnitude of field stars
CL : Cloud cover
Dir : Observation direction(Z : Zenith)
Radiant point:
No. Ls YMD(UT) CONST R.A DEC N d Wt Vel Mag HR Obs. Meth
------------------------------------------------------------------------------------
1. 191.066 1998/10/04.48 Gamma-Dra 262 +52 4 1.5 1 S-rS 2.8 1.3 OSAKA V(P)
2. 192.011 1998/10/05.44 Mu-Dra 257 +54 4 3 P rS 2.5 4.8 SAKMI V(P)
3. 192.986 1998/10/06.43 Gamma-Dra 265 +55 5 3 1 S-rS 3.2 2.2 OSAKA V(P)
4. 194.051 1998/10/07.51 Beta-Dra 265 +52 5 3 P S-rS 1.2 8.6 SAKMI V(P)
5. 194.998 1998/10/08.47 Gamma-Dra 265 +53 15 3 2 S-rS 1.2 6.4 SAKMI V(P)
6. 195.048 1998/10/08.52 Xi-Dra 270 +57 23 2 2 S 3.0 26.0 KONHI TV 21h05m-21h59m
7. 195.067 1998/10/08.54 Xi-Dra 271.0 +58.2 22 4 4 vS 3.0 11.0 NUMSH TV 24mmF1.4,50mmF1.2,85mmF1.2,21h00m-23h00m
8. 195.087 1998/10/08.58 Gamma-Dra 267.4 +57.1 5 3 5 S 1.4 36.0 SEKTA TV 20:00-23:00,28mm,F1.8,48deg
N : Number of meteors
d : Diameter of R.P.
Wt : Weight(P,1-5 P : poor)
Mag : Mean Magnitude
Vel : Velosity(vS S rS M rR R vR)
<-Slow Rapid->
Method : V:Visual T:Telescopic, P:Plotting C:Counting
Fireball
10/07 12h11m21s(UT) Mag=-3 Vol=rS 298,+47 -> 310,+43
Other information as below.
SAKMI saw a Giacobinid meteor around 10h UT on Oct. 1 and Oct. 3.
SEKTA saw a Giacobinid meteor with 0 magunitude at 9h44m UT on Oct. 2.
ITOOS saw a Giacobinid meteor with 1 magunitude around 10h UT on Oct. 6.
Search for NMS radiant point database with following requirements.
[requirements]1970-1998, 10/1-20, 247≦α≦277, 39≦δ≦69, N≧4
Ls Date(UT) R.P name R.A Dec N d Wt Vel Mag HR Obs. Method
----------------------------------------------------------------------------------------
196.603 1931/10/09.92 - 265 +53 5 - 2 - - - - V
197.465 1953/10/10.438 - 265 +52 5 - 2 - - - - V
196.406 1969/10/09.46 - 265 +54 5 - - - - - - V
195.932 1971/10/09.5 Gamma-Dra 263 +52 4 - - - - - Oikawa Kiyohiko V
195.454 1985/10/08.60 Gamma-Dra 264 +58 8 3 1 - - 3.0 Ueda Keiko V
195.365 1985/10/08.51 Nu-Dra 266 +55 4 3 1 - - - Fukuoka-Astron.G V
195.434 1985/10/08.58 Gamma-Dra 273 +53 7 - - - - - Kochi-Univ.G V
195.375 1985/10/08.52 Gamma-Dra 277 +55 13 5 1 - - - Takanashi Masaaki V
195.252 1997/10/08.47 Xi-Dra 271 +58 6 3 1 vS-S 2.7 2.0 Hashimoto Takema V
195.232 1997/10/08.45 Gamma-Dra 272 +54 6 8 1 vS-rS 3.3 2.0 Osada Kazuhiro V
Maximum activity of Giacobinids (newsflash)
[Up date : October 10 at 16(UT). Written by Takanashi Masaaki and Transrated by Hashimoto Takema.]
Number of observers : 38
Total observation time : 4,636minutes
Number of Giacobinid meteors : 1,862
Hourly rate
-----------------------------------------------(NMS)---------(IMO)---
UT JST N ave-HR ZHR SD ZHR SD
(r=1.6) (r=2.6)
---------------------------------------------------------------------
Oct.8 09:00-10:00 8/9 18:30 4 7 19 6 41 21
10:00-11:00 8/9 19:30 7 7 21 12 35 19
11:00-12:00 8/9 20:30 14 13 56 30 105 45
12:00-13:00 8/9 21:30 18 24 155 76 304 133
13:00-14:00 8/9 22:30 25 55 393 244 585 319
14:00-15:00 8/9 23:30 20 14 161 115 230 135
15:00-16:00 8/9 00:30 8 3 107 74 156 123
16:00-17:00 8/9 01:30 1 2 98 - 140 -
---------------------------------------------------------------------
Sellection condition as follows:
− Individual observation.
− Observation time is more than 30 minutes.
− Limiting magnitude is more than 4.0.
− Cloud cover is less than 4.
− R.P. altitude is more than 10 deg.
38 observers as follows:
T.Hashimoto, I.Hatsukade, D.Ito, K.Izumi, H.Izumimoto, Y.Kawai,
S.Kaya, I.Kisanuki, W.Kobayashi, K.Kuragaki, K.Maeda, K.Mameta,
T.Maruyama, K.Nakamura, Y.Nojima, K.Nozaki, H.Okayasu, K.Osada,
M.Sakaguchi, M.Sato, T.Sato, M.Takanashi, A.Takeda, S.Takeda,
K.Tanaka, Si.Tanaka, Sy.Tanaka, K.Terakubo, Y.Tonomura, T.Torigoe,
S.Uchiyama, S.Uehara, Y.Yabu, M.Yamamoto, S.Yanagi, S.Yoshida,
H.Yoshidome, S.Yoshino
Number of observers : 23
Total observation time : 2,340 minutes
Number of Giacobinid meteors : 1,402
rate of 10 minutes interval
-----------------------------------------------(NMS)---------(IMO)---
UT JST N ave-HR ZHR SD ZHR SD
(r=1.6) (r=2.6)
---------------------------------------------------------------------
Oct.8 11:00-11:10 8/9 20:05 3 2 7 12 13 23
11:10-11:20 8/9 20:15 4 2 6 12 12 23
11:20-11:30 8/9 20:25 5 17 72 13 147 34
11:30-11:40 8/9 20:35 5 13 62 69 126 143
11:40-11:50 8/9 20:45 5 18 82 46 165 86
11:50-12:00 8/9 20:55 5 17 88 34 211 120
12:00-12:10 8/9 21:05 8 18 100 35 218 97
12:10-12:20 8/9 21:15 8 20 114 45 248 111
12:20-12:30 8/9 21:25 8 21 129 80 265 166
12:30-12:40 8/9 21:35 8 31 203 96 412 201
12:40-12:50 8/9 21:45 12 61 335 263 530 304
12:50-13:00 8/9 21:55 14 64 385 226 614 280
13:00-13:10 8/9 22:05 13 96 616 374 943 595
13:10-13:20 8/9 22:15 15 94 627 386 904 565
13:20-13:30 8/9 22:25 15 64 438 305 616 437
13:30-13:40 8/9 22:35 16 42 327 169 483 223
13:40-13:50 8/9 22:45 15 26 218 143 307 197
13:50-14:00 8/9 22:55 13 30 267 173 371 227
14:00-14:10 8/9 23:05 10 25 247 142 325 145
14:10-14:20 8/9 23:15 11 14 155 129 196 143
14:20-14:30 8/9 23:25 9 16 187 155 230 188
14:30-14:40 8/9 23:35 4 8 87 117 90 110
14:40-14:50 8/9 23:45 2 9 156 68 224 110
14:50-15:00 8/9 23:55 2 9 171 74 239 114
---------------------------------------------------------------------
Sellection condition as follows:
− Individual observation.
− Observation time is more than 5 minutes.
− Limiting magnitude is more than 4.0.
− Cloud cover is less than 4.
− R.P. altitude is more than 10 deg.
23 observers as follows:
T.Hashimoto, D.Ito, H.Izumimoto, Y.Kawai, W.Kobayashi, K.Kuragaki,
K.Mameta, K.Nakamura, H.Okayasu, K.Osada, M.Sato, T.Sato,
M.Takanashi, A.Takeda, S.Takeda, Si.Tanaka, Sy.Tanaka, K.Terakubo,
S.Uchiyama, S.Uehara, Y.Yabu, S.Yanagi, S.Yoshino
Giacobinids are rich in faint meteors. Sky conditions and perception
coefficient of observers affect heavily on ZHR estimates. Bright Moon
hindered observations and SD are rather large.
According to the analysis of rate of 10 minutes interval, It seems that The peak of
Giacobinids was around 13h10m(UT) on October 8 (lambda = 195.075).
There are detail data and information in the Nippon Meteor Society home page