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(meteorobs) Re: June Bootids from Xinglong, China
Huan,
Rainer is referring to the ZHR of your sporadics. With a limiting magnitude of 4.9 the correction factor to magnitude +6.5 is near 6.4, which yields a rate of 77 sporadics per hour. Therefore your data states that someone under skies with a limiting magnitude of +6.5 will see 77 sporadic meteors per hour.
You must be underestimating your limiting magnitude. If your LM was truly +4.9 then you should not be seeing more than 2 sporadic meteors per hour.
Which method of estimating limiting magnitudes are you using? I endorse the IMO's "star counting" method. With this method I obtain three estimates at the beginning and end of each hour. The three estimates are usually no more than .3 of a magnitude apart and usually much closer.
Clear Skies!
Bob Lunsford
> From: "Huan Meng" <meteorobs_menhu@hotmail.com>
> Date: 2003/06/29 Sun AM 07:49:19 EDT
> To: <meteorobs@atmob.org>
> Subject: Re: (meteorobs) June Bootids from Xinglong, China
>
> Rainer,
>
> I'm sorry that i still did not understand the error in my report that you've stated.
> I think the sporadic hourly rate of about 10 is very common and usual. I'm not sure what's the 77 indicative of ...
> However, it cannot be a common value of the number of sporadic meteors observed in an hour.
>
> I attach the full list of my records below. i hope it's useful for you.
>
> (time in UT)
> 18:19 start
> sky obscured 10%
> #14, N=6
> #13, N=5
> SPO +3
> 18:20 SPO -2
> 18:23 SPO +2
> 18:27 SPO +3
> 18:31 SPO +4
> 18:36 SPO +0
> 18:38 #14, N=7
> 18:39 SPO -2
> 18:42 SPO +2
> 18:49 SPO +3
> 18:51 JBO +0
> 18:58 SPO +1
> 19:08 #14, N=5
> 19:13 SPO +3
> 19:14 SPO +0
> 19:16 break
> 19:17 resume
> 19:20 #14, N=5
> end
>
>
> Clear skies,
> Huan
>
>
> ----- Original Message -----
> From: "RainerArlt" <rarlt@aipdot de>
> To: "Meteorobs List" <meteorobs@atmob.org>
> Sent: Sunday, June 29, 2003 3:09 PM
> Subject: (meteorobs) June Bootids from Xinglong, China
>
>
> > > -----------------------------------------------------------------------
> > > | Period |Field |Teff| F | lm | JBO| ___| ___| ___| ___| ___| ___|Spor|
> > > | (UT) |RA Dec| h | | m |M| N|M| N|M| N|M| N|M| N|M| N|M| N|M| N|
> > > |-----------------------------------------------------------------------|
> > >1|1819-1920|255|+40|1.00|1.1| 4.9|C| 1| | | | | | | | | | | | |C|12|
> > > -----------------------------------------------------------------------
> >
> > Thanks, Huan, for the additional report of the critical time of
> > June Bootid activity. There is something else, I would like to
> > share with the observers' community. The sporadic hourly rate of
> > this period is 77, while it is expected to be of the order of 10-15.
> > It looks like a systematic error is creeping into the observation.
> > I think it is essential that observers keep an eye on their records
> > for deviations from what's possible. A high-perception observer
> > may see rates of 20-30, but I still think 77 is at the high end.
> > Something must go wrong here.
> >
> > Best wishes,
> > Rainer
> > (visual@imodot net)
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