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(meteorobs) Orionids Observation in Oct. 20/21
Observation of Orionids in Oct. 20/21
I went to a new site with Bing LI (who is an astronomy teacher in one
of Beijing's Youth Science and Technology Centers and we were in the
same department when we learnt astronomy in university) in Oct. 20.
The site is the radio station of my Observatory, some 100 km north of
Beijing. (see http://www.bao.ac.cn/bao/station/my/ for image of the
telescope). It will opened to public during the Leonids and we were going
to estimate the skybackground etc. for this location. I worked in this
station during 1991-1992 when I first came to the observatory.
It usually takes 3 hours or less by car to the station, but we took 5 hours
because of not familar with the road, and arrived there in 8:30 pm. It might
be the first time for Bing to drive so long distance I guess.
There seemed not be too much stars on the sky when looked from inside the
station, because of cloudy as well as several strong lamps nearby. We decided
to start observation after midnight. When Bing took rest, I visited the
guard (who was already there 7 years ago) and asked him to keep the main
gate unlocked. Then spent some time on learning how to use the new tape
recorder which was just bought that morning (my previous one which I bought
for Giacobinid observation was brought to mountain for I didn't think that I
could make observations in other sites), which was worthy for I found that
the recorder has auto-reverse function, which can continue playing by
auto-reverse to another side when playing, but the function does not work
for recording, in this case the tape must be placed in right direction. The
same thing happened later with Bing's tape recorder when we arrived
observation spot.
I took a nap for 40 minutes and got up at midnight. Only one star I could
see. Although I myself is accustomed to night observation (but not meteors
before), Bing is not, and she just had a long driving. So I waited a while
and then knocked her door and told her that it was cloudy. She came out
quickly and we drove to outide after 00:30 am.
The station locates in the north bank of Miyun reservoir, which likes a
huge lake. There are some large areas of plain ground between the station
and the lake, corns were already cut down and removed by farmers. The place
itself looked well for observation, and even no tree in that large area.
There must be some thin cloud and slightly foggy, a few stars above, with
some unknown birds singing (not sweetly) around. I just wished that there
could at least be one meteor (or fireball!) appeared sometime, which could
make me feel better to take Bing so long a distance to the cold night. That
would be her first meteor observation. Last time we went to Xinglong (the
optical station of the observatory on mountain) in Oct. 7 to observe the
Giacobinid, we had similar bad weather at the first night, and she had to
go back the next day morning and missed the shower we observed that evening.
It was nice that Bing borrowed the mini-bus from a friend, so we could
even read further for preparation with the IMO handbook which she brought
and Zay's guidebook which I just got from George (Thanks, George, it's
very helpful and I learned a lot starting from the first page). It was not
very cold at first, though turned to be quite cold later after 4 am.
There were occasionally some stars between clouds, so I learned to recognize
some constellations from Bing (Yes, I know Orion, but not Perseus, Auriga,
Taurus, and Gemini, and Bing knows quite well on those), and we picked out
two near-by fields for LM determination (No. 4 and No. 8).
We saw our first meteor at 2:57, a -1 Orionids! Only 2 corner stars of Field
No. 4 could be seen. 3 other Orionids were seen in that 10 minutes, then it
turned to completely cloudy. However, it began to much clear at about 3:30,
so we started observation quickly. I still felt not quite prepared myself
as I was not quite familar with nearby constellations, and it seemed that
there might be some small items to be done for a slightly comfortable
observation in such a new place, so I decided just looking around and gave
Bing my glasses (which is the simplest one with the lowest degrees of 100X100
and with the lowest cost of less than 4 US$ which I bought last month for
meteor observation - but it really helps and gives 0.5 mag fainter LM?).
Both of us use tape recorder to record everything (my new one has much smaller
pause button then previous one). She had 1 hour 9 minutes total observations
with only 5 seconds dead time when she checked her recorder after the first
side of the tape was over, and we ended up the formal observation at 04:43
when she felt a little tired (the chairs we found from the station were very
hard and uncomfortable) and cold, and the Pleiades which she was looking at
during the period going lower west. All together she saw 27 ORI and 8 SPO
in Teff=1.15 under LM=4.8 to LM=5.1. However, the best one of the night
was a possible fireball which just showed in front of us with long path and
a train when we were facing the north about 10 minutes later after
finishing the formal observation. The Orionids observation gave me
different feeling, for I saw several meteors with train (0.2 to 0.5 s?),
which was never noticed before when I saw meteors at night. And this
observation experience would probably make Bing a steady meteor observer
- I think that she will soon join this meterobs list. I myself is also
preparing to take some meteor observations each month near the new moon,
and encourage some meteor observers within our observational assistants
on mountain. :) It's sad at this moment that after I came to mountain in
Oct. 24 for some Orionids observation of my own, it began to rain and now
it is snowing outside! Just wondering whether it could be fine before Friday.
I attach at the end of this message the raw observation log which Bing
inputed based on tapes. The summary report was made based on her raw data
file.
Clear skies, Jin
============================================================================
Jin Zhu | Tel.: +86-10-62759888 (O)
Beijing Astronomical Observatory | +86-10-68392030 (H)
Chinese Academy of Sciences | +86-314-5053035-806 (Schmidt dome)
P. R. China | Fax : +86-10-62759888
----------------------------------------------------------------------------
email: zj@bac.pkudot edu.cn or jinzhu@sun.ihep.ac.cn
WWW Home Page: http://vega.bac.pkudot edu.cn/~zj
Pager: zhu@mail.263dot net.cn (only Sub. line) OR +86-10-64256688 PIN 82333
============================================================================
NAMN Visual Observing Form:
Summary Report
DATE: 1998 Oct. 20/21 BEGIN: 19:34 UT END: 20:43 UT
OBSERVER: Bing Li
LOCATION: Long: 116:54:-- East; Lat: 40:30:-- North
City & State: Miyun, Beijing, China Elevation: 157 m
RECORDING METHOD: Tape Recorder
----------------------------------------------------------------------------
OBSERVED SHOWERS: (Use 3 letter Codes)
ORI
SPO
----------------------------------------------------------------------------
OBSERVING PERIODS:
0 = None seen; / = shower not watched.
PERIOD(UT) FIELD LM DRA SPO
19:34-20:43 Pleiades 5.0 27 8
---------------------------------------------------------------------------
MAGNITUDE DISTRIBUTIONS:
SHOWER -7 -6 -5 -4 -3 -2 -1 0 +1 +2 +3 +4 +5 +6 TOTAL
ORI 0 0 0 0 0 0 0 0 2 4 9 6 6 0 27
SPO 0 0 0 0 0 0 0 0 1 0 2 1 4 0 8
---------------------------------------------------------------------------
SKY OBSCURED:
___0_% FROM: 19:34 UT
TO: 20:43 UT
---------------------------------------------------------------------------
DEAD TIME: 0
BREAKS: 0
---------------------------------------------------------------------------
LIMITING MAGNITUDE:
STAR STAR
TIME AREA COUNT LM
19:27 No.4 4 > 4.3
19:27 No.8 6 4.8-5.0
19:56 No.4 5 4.3(-4.9)
19:56 No.8 6 4.8-5.0
20:34 No.8 7 5.1
MEAN LIMITING MAGNITUDE: 4.9
---------------------------------------------------------------------------
REMARKS:
Teff = 1.15 hour
----------------------------------------------------------------------------
Raw data of the observing orionids
(by Bing Li)
98.10.20/21
Time: Beijing Time
0:00--2:57 only few stars can be seen
2:57 ori -1
2:57 LM: 4/2
3:00 ori 1
3:01 ori 2
3:07 ori (by Zhu)
cloudy (can not see the Ori constellation)
3:15 LM: 4/4
3:20 ori 2
3:26 ori 2 (train)
3:27 LM: 8/6 4/4
3:34 start
direction: The pleiades star cluster
3:36 ori 3
3:37 ori 4
3:40 spo 5
3:41 ori 4
3:44 ori 4
3:49 spo 5
3:52 ori 3
3:53 ori 4(0.5s train)
3:53 ori 5
3:56 LM: 4/5 8/6
3:59 spo 5
4:03 ori 5
4:05 ori 3
4:05 ori 5
4:07 ori 3
4:08 ori 3
4:09 ori 5
4:09 ori 2
4:11 spo 5
4:11 spo 3
4:16 ori 4
4:16 ori 1
4:17 ori 1
4:19 ori 4
4:19 ori 3
4:24 spo 3
4:29 ori 5
4:29 ori 3
4:30 spo 4
4:33 ori 3
4:33 ori 2
4:34 LM: 8/7
4:34 ori 2
4:36 spo 1 (train)
4:37 ori 2
4:39 ori 5
4:41 ori 3
4:43 end