(meteorobs) Reporting Quadrantid observations
Rainer Arlt
rarlt at aip.de
Tue Jan 1 10:33:16 EST 2008
Happy New Year!
The maximum of the Qudrantids is approaching, and some recommenda-
tions for reporting meteor observations may be useful. The electronic
form at the IMO site, http://www.imo.net/visual/report/electronic, has
been very useful in producing consistent and well formated reports
for further processing, and for immediate activity analyses. It has
not always been easy to be used by everybody though. Perhaps a few
comments help:
- The date is the local double-date. Do not worry about UT dates.
The Quadrantid maximum night is '03/04 01 2008' for nearly all
observers.
- The geographical coordinates are longitude/latitude. Note that
some internet services work with latitude/longitude.
- Please report short observing periods for the maximum night. Period
lengths of 15 minutes or less are recommended. The electronic form
offers 10 periods by default. There is a link to customize the form.
But I recommend to split your observation into smaller individual
observations. Input may be spoiled by internet connection or other
technical problems, and the loss is smaller then.
- The field of view is in degrees both in RA and Dec. If you wish to
convert RA = 13h into degrees, multiply it by 15, RA = 195 deg.
- Teff is the effective observing time in decimal hours. If an ob-
serving period lasted from 0219-0230, it is 11 min = 0.183 h.
- F is the field obstruction correction. If clouds disturbed 10%
of your field (not of the sky) during one period, the fraction
of field covered is 10% / 100% = 0.1. Then F = 1/(1-0.1) = 1.11.
Other examples are: 20% -> 1.25, 30% -> 1.43, 40% -> 1.67, 50%
-> 2.00. Just use these numbers if you feel usure about the maths.
- Lm is the stellar limiting magnitude. It is the magnitude of the
faintest stars visible to the naked eye; it's observer-specific.
If you face transparent clouds, do not report both a cloud cover
and a reduced limiting magnitude. An Lm reduction is usually suf-
ficient.
- Magnitude distributions of the Quadrantids should be given for
a maximum of two combined periods. Please also give the magnitude
distributions of the other showers (ANT and COM) and the sporadic
meteors. One distribution per night is sufficient. You may need to
increase the number of magnitude distributions shown in the form by
the 'customize' link at the top. Do that before entering any data.
- The ecliptical source ANT (Antihelion source) does not show a
radiant position at the moment. Do not worry about this.
- If you notice an error in the data you submitted, please send a
message to geert at barentsen.be and visual at mo.net and do not submit
the observation again.
Geert Barentsen has set up a live activity graph page on the IMO web
site -- http://www.imo.net/live/quadrantids2008/
Observations sent in by the electronic form will show up on the live
page after a few minutes.
Good luck for the Quadrantids!
Rainer
Visual Commission of the IMO
--
Rainer Arlt -- Astrophysikalisches Institut Potsdam, Germany
www.aip.de/People/rarlt -- +49-331-7499-354 -- fax: -526
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