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Re: (meteorobs) comet LINEAR 2001 A2 orbit

> I calculate the distance of the comet's ascending node at 1.0936AU.
> (can anyone confirm?)
> This is pretty close to Earth's orbit!
> So maybe we may get to see associated meteors, especially since this is not
> the comet's first trip into the inner solar system.
> 
> Cheers,
> Michael Mattiazzo
> Wallaroo, South Aust
> mmatti@yp-connectdot net

Some details on the comet:

C/2001 A2 (LINEAR) 
   From 265 observations 2001 Jan. 3-Apr. 6. Kinoshita
   Epoch = 2001 May 11.0 TT = JDT 2452040.5 
       T = 2001 May 24.52464 TT             peri.= 295.32657 
       e = 0.9994236                        node = 295.12701 (2000.0) 
       q = 0.7790393 AU                     incl.=  36.48270 
  m1 = 7.5 + 5log(delta) + 25.0log(r) 
  A. Node = E:07/18.0 JST  O:2001/07/04.5 JST  1.091 AU 
  D. Node = E:01/15.6 JST  O:2000/12/12.5 JST  2.721 AU


              EQUINOX: 2000.0;       DATA FOR YEAR: 2001
 --------------------------------------------------------------------
 METH.  ALPHA  DELTA    VG      VH        L     DATE-MAX.    D-DISC.
  Q+    107.6  -21.0   30.74   41.77    115.1   JULY 17.7    0.053
  B+    107.5  -21.1   30.62   41.66    115.1   JULY 17.7    0.053
  W+    108.9  -25.2   29.74   41.77    115.1   JULY 17.7    0.120
  A+     99.8  -25.9   30.80   41.77    106.5   JULY  8.6    0.106
  H+    105.0  -24.5   29.64   41.77    109.6   JULY 11.9    0.071
  P+    107.1  -22.2   29.84   41.77    112.4   JULY 14.8    0.048
 --------------------------------------------------------------------
 FIRST/SECOND (-/+) SET OF DATA CONCERNS THE PRE-/POST-PERIHELION ARC
 THE BEST METHOD - PRE-PERIHELION ARC:  B     (D = 0.464)
                 - POST-PERIHELION ARC: P     (D = 0.048)

 ADDITIONAL INFORMATION:
    (-) DIST. =   0.986 AU;   DT =   -44.5 DAYS;   MIN. DIST. = 0.4947 AU
    (+) DIST. =   0.318 AU;   DT =    13.9 DAYS;   MIN. DIST. = 0.0511 AU

These theoretical radiants are computed according to
the programme by 
NESLUSAN L., SVOREN J., PORUBCAN V.: 1998, "A COMPUTER PROGRAM
FOR CALCULATION OF A THEORETICAL METEOR-STREAM RADIANT", ASTRON.
ASTROPHYS. 331, 411-413. The actual methods are
      - (Q) Q-ADJUSTMENT (HASEGAWA; 1990)
      - (B) VARIATION OF PERIHELION DISTANCE AND EXCENTRICITY (SVOREN
            ET AL; 1993)
      - (W) ROTATION OF THE LINE OF APSIDES (STEEL AND BAGGALEY; 1985)
      - (A) ROTATION AROUND THE LINE OF APSIDES (SVOREN ET AL; 1993)
      - (H) OMEGA-ADJUSTMENT (HASEGAWA; 1990)
      - (P) PORTER'S METHOD (PORTER; 1952)


They use various methods to alter the orbit of the comet to obtain 
an intersection with the orbit of the Earth. The D-DISC. gives
the similarity between original and wltered orbit and is nice if
small (<0.1). Look at the ascending node:
Very small D-DISC. with radiant 

   alpha=107  (7h08m),   delta=-22,   v_inf = 32 km/s
   on July 17/18

Unfortunately, the shower is a totally daytime one. Let's wait for
the forward-scatter radio results...

Best wishes, Rainer

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