(meteorobs) Ursid and Quadrantid?

[Roberto Gorelli]

On Sun, 28 Dec 2014 08:47:36 +0000
  Tony Markham <tonymarkham832 at gmail.com> wrote:
> Hi Paul,
> 
> The problem is of course that meteor streams don't have "rigid" 
>boundaries
> and it is therefore somewhat arbitrary as to when we start 
>describing
> outliers that are being perturbed out of the meteor stream as 
>sporadics
> rather than as Quadrantids. In the past, such meteors occurring well
> outside the "traditional" shower dates would always have been called
> sporadics.
> 
> Nowadays, however, video networks can calculate their orbits and 
>note that
> the orbits have similarities to that of the Quadrantid meteor 
>stream.
> However, I don't believe that it is helpful for websites to list 
>these as
> definite Quadrantids or to extend outwards the activity dates quoted 
>for
> the Quadrantids (that would only mislead people who write Sky Diary
> columns). At best, I would describe such meteors as "Quadrantid 
>outliers".
> The activity dates quoted for the Quadrantids should continue to 
>represent
> the dates during which the meteor shower would be apparent to an 
>observer
> with dark skies.
> 
> Tony
> 
> On 28 December 2014 at 08:15, Paul Zeller <pzeller1966 at gmail.com> 
>wrote:
> 
>>   It may have been a sporadic. However, the information I have from 
>>the
>> web tells me the Quadrantids start as early as December 28. Also, 
>>the
>> SpaceWeather.com site has been cataloging Quadrantid fireballs for 
>>the last
>> couple of weeks. So I'm not sure I can just write this one off as a 
>>chance
>> random sporadic. Anyone else out there with any thoughts about this?
>> On Dec 26, 2014 5:58 AM, "Roberto Gorelli" <md6648 at mclink.it> wrote:
>>
>>> On Fri, 26 Dec 2014 04:57:16 -0500
>>>  Paul Zeller <pzeller1966 at gmail.com> wrote:
>>>
>>>>  I had very clear skies for most of the night and decided to get out 
>>>>and
>>>> count/plot meteors, though we're between major showers. I observed
>>>> between
>>>> 8:00 - 9:05 UT Dec. 26. LM near 5.0 with some high clouds moving in 
>>>>by
>>>> the
>>>> end. I was watching high in the Northwest. Only 4 meteors seen, and 
>>>>2
>>>> were
>>>> Sporadic. But from the speed and direction, I'm almost sure that one 
>>>>was
>>>> a
>>>> late Ursid while another was an early Quadrantid. Is this possible? 
>>>>I
>>>> realize that both showers are known for very sharp, short lasting 
>>>>peaks,
>>>> and that we're almost four days past the Ursid peak and nine days 
>>>>away
>>>> from
>>>> the Quadrantids peak. I just wanted to throw this out there! Paul Z.
>>>> Indianapolis IN USA.
>>>>
>>>
>>>
>>> Quadrantids at 26 december, nine days before the peak? Sorry, 
>>>pratically
>>> impossible, probably sporadic meteor casually in the right direction 
>>>and
>>> speed.
>>> Best greetingsw.
>>> Roberto Gorelli

For to be sure that a meteor come from a specific shower we should 
have the orbit, possibility from two or more stations and the spectum,
in near all cases we havent this, only very sometime with bolids we 
can to have this data and then we can said that a meteor come from a 
specific shower.
In general the Astronomers utilise the criterium D for to link a 
meteor at a shower, but there where different D criteriums, I think 
that the best it's the Dsh (Southworth - Hawkins) but I can said too 
that the criterium D, IHMO, it's not totally right, I think that in 
the future I shall write a new criterium D many different from all 
present D criteriums (Dd Drummond 1981, Dh Jopek 1993, DN Valsecchi 
and &, Dv Jopek, Rudawska and Bartczak 2008, Db Jenniskens 2008).

It's possible that the meteors in discussion came from Quadrantids but 
for said this we must stand by for future observations or a search on 
old meteor orbital catalogues.

Best greetings.
Roberto Gorelli