(meteorobs) The meteor showers MID, PBO (and possibly ADR) and Comet P/197 Linear
tpub at Safe-mail.net
tpub at Safe-mail.net
Tue Dec 8 15:28:34 EST 2015
With low inclination comets and especially Jupiter Family Comets, the usual tests for orbital similarity hit a bit of a snag at times, namely testing to see if an orbit has a limited probability of being random is tricky when the distribution of the orbits of all low inclination objects that are also potential Jupiter Family Comets/Objects is not actually random.
PBO are the phi Bootids. First mentioned by Jennisken in his 2006 book in table 9, based on possible asteroidal precursor. The May iota Draconids are just published in the currently recentmost WGN (or JIMO if preferred).
Meteors (and a list is presented below), including past radar orbits, can be shown to match via D criterion to the comet’s orbit. Some of these also match to MID orbital particulars, and some others to PBO particulars. One has elsewhere been matched to even ADR particulars, but via radiant clustering methods. The rest are all classed as sporadic by their discoverers.
One matches both MID and PBO via D Criterion. The orbits are fairly similar, but there is a subset that is off just a bit primarily in incination.
In the distant past meteor astronomy has been dogged by not readily available to all obscure texts containing radiants, and showers identified/proposed from very few candidates. Unfortunately Jenniskens table 9 of possible asteroidal showers is a bit similar in this respect. Granted it predates the plethora of data now available from double station and other meteor orbit sources, but they do all tend to get into the IAU MDC working lists. This despite a book not really being a peer reviewed publication, nor necessarily containing and/or showing the “working out”. The PBO appear to have orbital and radiant particulars based on two to three orbits via past surveys and/or paper by Southworth and Hawkins, Lindblad and one particular fireball shower list which has always been remarkable for the immense number of showers found in a very very small dataset (many are “two to three meteor showers, nearly all meteors fit a “new” “shower”).
The Southworth and Hawkins referenced radiant particulars and peak in table 9 of Jennisken’s book tally very well with the May iota Draconids.
Given the range of it looks likely MID and PBO are synonymous. As may even be ADR, as particulars gleaned from a sample of two to three objects from surveys that were limited in temporal coverage (ie they could just as well have only found the last one or two of a longer duration stream not fully covered in time) may not be representative of the overall shower.
The trouble is on the other hand the celestial mechanics of our solar system (especially Jupiter’s influence) lead to objects with inclinations near to the orbital plane of the Solar System ending up similar in nature with respect to orbital elements, even if they started off in distinguishably distinct orbital elements.
Unfortunately the orbital dynamicists interested in meteors seem to have more of a wish to find some spectacular shower and/or just plain new cometary association to bother looking around at extant lists.
Otherwise the predictions for P/197 Linear here
<http://feraj.narod.ru/Radiants/Predictions/197p-ids2015eng.html>
(found simply via a google search to see if any meteoric association with P/197 Linear was already categorised)
would have had their radiant readily associated with the then known meteor radiant PBO, although the occurrence time is a bit off. Comparison against available meteor orbits would have shown meteors could be associated with the comet, though a little more complex to do, the data are available online.
The new MID shower compares with the above prediction even better.
The ADR isn’t so clear, but showers based on a handful of less certain orbits for not fully covered shower temporal spreads are problematic. At best.
There is certainly a close similarity for meteor orbits against MID and PBO radiants and orbits. Whether this is sufficient enough to make a valid association of the two, with one set slightly evolved in orbit compared to the other, or whether there is a level of similarity due to the not so tender mercies of Jupiter, well there might not be enough data to say as of yet.
Some of the current CAMS papers submitted to Icarus may have clarification on some of these matters, but I’ve no access to those to see as yet, but if they cover the point this note here is irrelevant..
The below orbits include ones from SonatoCo, Croatian Meteor Network and EDMOND publicly available datasets. Headings should be self explanatory.
Having read the EDMOND papers I’m not entirely clear how many are true dual station derived orbits and how many are ones derived via cross correlating separate single station orbits and declaring them the same object. There are certainly caveats with regards to mixed quality, if not lower quality, orbits in those papers. I mention this solely as up to half the meteors are from the EDMOND dataset.
Having coincidentally noticed CAMS 2.0 public dataset is available now I’ve included matches from that too, after the other stuff. Thanks to Peter J for making that public. There’s just over half a million orbits publicly available in total now, of reasonable to good quality.
Yours
John Greaves
ID D ra2000 de2000 lambda0 Vgeo mag q ecc incl argper ascnode stream YY MM DD
ED20130520_212457 0.08 232.080 59.710 59.820 17.1 0.0 1.0000 0.6100 25.790 189.240 59.820 spo 2013 5 20.890
20130521_205020 0.08 228.420 59.300 60.400 17.3 -1.8 1.0000 0.6300 26.030 188.370 60.400 spo 2013 5 21.460
ED20110522_222928 0.08 240.420 60.170 61.330 18.0 0.5 1.0000 0.6000 27.860 189.020 61.330 spo 2011 5 22.930
ED20080523_224334 0.07 229.610 60.240 63.030 15.9 0.0 1.0100 0.5900 23.610 186.640 63.030 spo 2008 5 23.940
052425ZGR0004 0.09 242.960 60.710 63.170 19.0 0.0 1.0000 0.5900 29.870 188.580 63.170 spo 2011 5 24.850
ED052425ZGR0004 0.09 242.960 60.710 63.170 19.1 0.0 1.0000 0.6000 29.990 188.570 63.170 spo 2011 5 24.850
ED20100524_220014 0.06 239.940 59.450 63.470 18.2 -0.1 1.0000 0.6000 28.090 189.470 63.470 spo 2010 5 24.910
20090527_022105 0.09 234.880 52.350 65.450 15.9 0.2 0.9900 0.6400 22.380 195.420 65.450 spo 2009 5 26.720
ED20110529_231653 0.09 228.110 55.020 68.080 16.4 0.0 1.0000 0.6900 22.920 189.930 68.080 spo 2011 5 29.970
ED20120529_215237 0.07 232.670 64.680 68.730 16.6 0.0 1.0100 0.5900 25.460 180.640 68.740 spo 2012 5 29.910
20130531_214206 0.07 236.920 56.110 70.030 16.9 0.8 1.0000 0.5800 25.760 190.390 70.030 spo 2013 5 31.500
20100602_235220 0.05 233.970 62.390 71.820 16.9 0.6 1.0100 0.6400 25.150 181.130 71.820 IwADR 2010 6 2.610
ED20110603_003805 0.08 245.160 66.910 71.970 17.7 0.0 1.0100 0.5800 27.730 179.000 71.970 spo 2011 6 3.020
20130603_211321 0.07 231.430 57.030 72.890 16.7 1.2 1.0100 0.6300 24.750 186.840 72.890 spo 2013 6 3.500
ED20110604_015304 0.09 235.480 63.980 72.980 17.6 0.4 1.0100 0.7000 25.550 181.490 72.980 spo 2011 6 4.070
060506MLA0027 0.08 241.700 65.300 75.110 16.5 2.2 1.0100 0.5800 25.360 179.760 75.110 spo 2010 6 6.050
ED060506MLA0027 0.08 241.700 65.300 75.110 16.5 2.2 1.0100 0.5800 25.390 179.760 75.110 spo 2010 6 6.050
id ra dec l0 vg mag q e incl argper ascnode str
YY MM DD
CAMS61853 219.92000 62.97000 67.25440 15.74 -1.80 1.013200 0.644000 22.7800 182.2500 67.2570 0 2012 5 28.35620
CAMS8526 224.60000 59.93000 72.31510 15.15 1.30 1.013200 0.601000 22.2200 184.4000 72.3220 0 2011 6 3.37859
CAMS61465 225.83000 54.93000 62.32700 15.90 -2.20 1.002100 0.631000 22.7600 193.2900 62.3260 0 2012 5 23.22527
CAMS61950 225.84000 63.20000 68.16470 15.54 -6.80 1.013100 0.589000 23.2700 182.9100 68.1660 0 2012 5 29.30502
CAMS63469 230.26000 64.09000 78.64970 16.79 0.60 1.015200 0.627000 25.2800 179.5900 78.6460 0 2012 6 9.25364
CAMS61016 231.80000 52.56000 58.60960 16.36 -1.90 0.991000 0.582000 24.0700 199.2600 58.6090 0 2012 5 19.36084
CAMS61404 234.41000 57.36000 61.53900 17.19 -3.10 1.002300 0.608000 25.8400 193.2200 61.5400 0 2012 5 22.40568
CAMS61239 235.43000 57.57000 60.37080 17.77 -2.90 1.001400 0.625000 26.7200 193.5100 60.3670 0 2012 5 21.19103
CAMS62282 235.55000 62.16000 70.11880 16.77 -1.80 1.012300 0.586000 25.7500 185.2900 70.1200 0 2012 5 31.34292
CAMS61483 239.17000 55.25000 62.37080 17.82 -2.90 0.996800 0.596000 27.1000 196.6300 62.3690 0 2012 5 23.27093
CAMS8471 239.68000 55.67000 65.62680 18.79 0.20 0.999600 0.658000 28.1900 194.9100 65.6290 0 2011 5 27.40402
CAMS62630 242.76000 59.55000 72.07080 17.88 -1.60 1.009400 0.590000 27.7900 189.2300 72.0710 0 2012 6 2.37988
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