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(meteorobs) Obs. Nov. 16/17, 2000 from China




LEO Obs. Nov. 16/17, 2000 from China

It was slightly snowing after dark, but from the weather forecast, there was
good possibility that it could turn to clear after midnight. I got up at 0:20am
and found that the moon was already there with several bright stars above
through thin clouds. I checked the detail radiant positions as well as their 
average speeds for all the four showers I would like to observe, then the
standard areas for limiting magnitudes. After Ju Zhao and Dan Xia came to
join me at about 1:30, we discussed the observations a little and then moved
sleepbags etc. to the roof of the building by the Schmidt telescope.

It turned to be more and more clear after 2:00. Just at the moment of 02:28 when 
Dan and I went to the roof to meet Ju, a yellow -1 STA slowly appeared in front 
of us. I decided to look to west to eliminate the interference of the bright
moon. I choosed my familar #17 AUR as my first LM area, and used a round table
to block the moon behind my head when I counted the stars in this area. To avoid
the possible large variation of LM introduced by the bright moon, I choosed
the #2 PER near the center of my field as the second LM area. During the whole
night, all of us usually could see 4 stars in #2 and 8 in #17, and I realized
after observation that there are too large gaps between these areas/numbers
at such a low LM (from 3.78 to 4.95 for #2 and 4.52 to 5.21 for #17) - it is
obvious that the simple average of 3.78 and 4.52 will give too low value,
and the real LM should be something between 4.52 to 4.95! So it should be
noted that #2 is not good for such a bright moon Leonids case. However, it may
also bring some problem to use areas far from the observing field.

Two AMOs were seen during the night, and it seems that this shower with also
very fast members should better be considered during the monitor of the Leonids.
The STA and NTA could be easily distinguished from their slowly moving and
short arcs near their radiants.

It seems that there were some very fast meteors came from somewhere further 
eastwards to Leo. At 4:27, Ju saw a very fast +2 meteor at somewhere out of
my field and shouted, Dan and I turned our heads to him immediately and we
saw a very fast +0 SPO just there - this was obviously not the same one Ju
referred to, but it seemed that the two may probably came parallelly from 
somewhere in the east.

After 4:30, feeling that the moon was too high and blocking it gave me a little
narrow clear field, I removed the table and change my field center rightward to
zeta Perseus, having the moon inside my field at the far left side. The LM
seems not change but from that time, I almost saw no meteors again for the
following 30 minutes except two satellites (the only ones I saw that night).
It seems that blocking the moon from your field is very important if you have
to observe in such situation - this was my first time to observe meteors during
moonlight and it had quite different feeling.

This was also my first time to use a digital voice recorder and which worked
well. So the voices could be easily recorded as computer files.

The complete report is as followes:

***************************
NAMN VISUAL SUMMARY REPORT
***************************
DATE: Nov. 16/17, 2000             BEGIN: 18:43 UT    END: 21:03 UT
OBSERVER: Jin Zhu (ZHUJI)
LOCATION: Long: 117 d 34' 42" East; Lat: 40 d 23' 47" North
Place: Xinglong, Hebei, CHINA       Elevation: 860 m.
RECORDING METHOD: Voice Recorder

---------------------------------------------------------------------
OBSERVED SHOWERS: 3-letter code; radiant position; radiant diameter

LEO ; RA 10h 02m  DEC +23 deg.;
STA ; RA 04h 03m  DEC +16 deg.;
NTA ; RA 04h 12m  DEC +23 deg.;
AMO ; RA 07h 31m  DEC +02 deg.;
---------------------------------------------------------------------
OBSERVING PERIODS: 0 = none seen;    / = shower not watched.

PERIOD(UT)         FIELD            Teff    F  LM  LEO STA NTA AMO SPO
18:43-20:00 RA 4h 30m  DEC +30 deg  1.30  1.05 4.8  3   2   1   2   1
20:01-21:03 RA 4h 00m  DEC +30 deg  1.05  1.05 4.9  5   0   0   0   2
---------------------------------------------------------------------
TOTALS                              2.35            8   2   1   2   3
---------------------------------------------------------------------
MAGNITUDE DISTRIBUTIONS:
SHOWER   -7  -6  -5  -4  -3  -2  -1  0  +1  +2  +3  +4  +5  +6  TOTAL
LEO       0   0   0   0   1   1   0  1   1   0   3   1   0   0    8  
STA       0   0   0   0   0   0   0  1   1   0   0   0   0   0    2
NTA       0   0   0   0   0   0   0  0   0   0   1   0   0   0    1
AMO       0   0   0   0   0   0   0  0   1   0   1   0   0   0    2    
SPO       0   0   0   0   0   0   0  1   1   0   1   0   0   0    3
---------------------------------------------------------------------
Total     0   0   0   0   1   1   0  3   4   0   6   1   0   0   16
---------------------------------------------------------------------
SKY OBSCURED:

Percentage(%)  Duration (UT)
 5             18:43-20:00
10             20:26-20:30
 5             20:31-21:03      
---------------------------------------------------------------------
DEAD TIME: None
BREAKS: None
---------------------------------------------------------------------
LIMITING MAGNITUDE:

          STAR      STAR
TIME      AREA      COUNT     LM
18:43      17         8       4.52
18:50       2         5       4.95
19:18       2         5       4.95
19:23      17         8       4.52
19:34       2         4       3.78
19:48       2         5       4.95
19:56       2         5       4.95
19:56      17         8       4.52
20:04      17         8       4.52
20:05       2         5       4.95
20:14      17         8       4.52
20:26      17         8       4.52
20:36      17         8       4.52
20:36       2         5       4.95
20:54      17         8       4.52
21:03      17         8       4.52

MEAN LIMITING MAGNITUDE: 4.8

---------------------------------------------------------------------
METEOR DATA:

#  TIME(UT)  MAG  VEL.  COLOR  SHOWER  TRAIN  MAP  ACCURACY
---------------------------------------------------------------------
1   18:53     +0   2      y     STA     
2   18:56     +3   5      w     SPO
3   19:00     +3   5      w     LEO
4   19:00     +1   2      w     STA
5   19:02     +1   5      w     AMO
6   19:29     +0   5      w     LEO     
7   19:29     +3   5      w     AMO
8   19:45     -2   5      w     LEO    1s
9   19:57     +3   1      w     NTA
10  20:08     +1   5      w     LEO    0.2s
11  20:15     +4   5      w     LEO
12  20:22     +3   3      w     LEO
13  20:23     +1   5      w     SPO
14  20:27     +0   5      w     SPO
15  20:28     -3   4      w     LEO    1s
16  20:31     +3   5      w     LEO

VELOCITY (VEL.) SCALE:
0 = Stationary
1 = Very Slow
2 = Slow
3 = Medium
4 = Fast
5 = Very Fast

---------------------------------------------------------------------
REMARKS:

The data was extracted from voice recorder by Dan Xia.
---------------------------------------------------------------------
<END OF REPORT>


Original records:

#  TIME(UT) SHOWER MAG SPEED TRAIN(SEC) MEM

   18:43 start
   FOV: RA 4h 30m  DEC +30 deg 
   showers: LEO,STA,NTA,AMO
   LM: 17/8, 2/5
   18:43 LM: 17/8
   18:50 LM: 2/5
01 18:53 STA +0 2  yellow 
02 18:56 SPO +3 5
03 19:00 LEO +3 5
04 19:00 STA +1 2
05 19:02 AMO +1 5
   19:18 LM: 2/5
   19:23 LM: 17/8
06 19:29 LEO +0 5 
07 19:29 AMO +3 5
   19:34 LM: 2/4 
08 19:45 LEO -2 5  1s
   19:48 LM: 2/5
   19:56 LM: 2/5
   19:56 LM: 17/8
09 19:57 NTA +3 1
   20:04 LM: 17/8
   20:05 LM: 2/5
10 20:08 LEO +1 5  0.2s
   20:14 LM: 17/8
11 20:15 LEO +4 5
12 20:22 LEO +3 3
13 20:23 SPO +1 5
   20:26 LM: 17/8
14 20:27 SPO +0 5
15 20:28 LEO -3 4  1s
   20:30 FOV: RA 4h 00m  DEC +30 deg table
16 20:31 LEO +3 5
   20:36 LM: 17/8
   20:36 LM: 2/5
   20:52 bright satellite +3 WNW->ESE flash
   20:54 LM: 17/8
   20:57 another bright satellite +3 S->N across the #17 LM area
   21:00 LM: 17/8
   21:03 end 

-- 
========================================================================
Jin Zhu                           | Tel.: +86-10-62751286 (O)
Beijing Astronomical Observatory  |       +86-10-62579689 (H)
Chinese Academy of Sciences       |       +86-314-5054767 (Schmidt dome)
P. R. China                       | Fax : +86-10-62765031 or 64888731
------------------------------------------------------------------------
email: zj@bac.pkudot edu.cn or jinzhu@sun.ihep.ac.cn
WWW Home Page: http://vega.bac.pkudot edu.cn/~zj
Pager: zhu_jin@263dot net (only Sub. line) OR +86-10-96300 PIN 682333
========================================================================
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