Här är sidan där jag hämtar data om kometens bana och relativ rörelse.
http://ssd.jpl.nasa.gov/horizons.cgi?s_type=1#top
Hastighetsvektorn får jag i bågsekunder/timme, får ev. räknas om till att passa det styrprogram man använder. Se data i de två sista kolumnerna och gäller för natten som kommer, 16:e december.
Någon kanske vet andra sidor där man kan hämta bandata?
/Lars
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Ephemeris / WWW_USER Sat Dec 14 00:55:07 2013 Pasadena, USA / Horizons
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Target body name: Lovejoy (C/2013 R1) {source: JPL#24}
Center body name: Earth (399) {source: DE-0431LE-0431}
Center-site name: (user defined site below)
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Start time : A.D. 2013-Dec-15 00:00:00.0000 UT
Stop time : A.D. 2013-Dec-16 00:00:00.0000 UT
Step-size : 60 minutes
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Target pole/equ : No model available
Target radii : (unavailable)
Center geodetic : 18.0000000,59.3833000,-8.09E-13 {E-lon(deg),Lat(deg),Alt(km)}
Center cylindric: 18.0000000,3256.41859,5465.8052 {E-lon(deg),Dxy(km),Dz(km)}
Center pole/equ : High-precision EOP model {East-longitude +}
Center radii : 6378.1 x 6378.1 x 6356.8 km {Equator, meridian, pole}
Target primary : Sun
Vis. interferer : MOON (R_eq= 1737.400) km {source: DE-0431LE-0431}
Rel. light bend : Sun, EARTH {source: DE-0431LE-0431}
Rel. lght bnd GM: 1.3271E+11, 3.9860E+05 km^3/s^2
Small-body perts: Yes {source: SB431-BIG16}
Atmos refraction: NO (AIRLESS)
RA format : HMS
Time format : CAL
EOP file : eop.131213.p140306
EOP coverage : DATA-BASED 1962-JAN-20 TO 2013-DEC-13. PREDICTS-> 2014-MAR-05
Units conversion: 1 au= 149597870.700 km, c= 299792.458 km/s, 1 day= 86400.0 s
Table cut-offs 1: Elevation (-90.0deg=NO ),Airmass (>38.000=NO), Daylight (NO )
Table cut-offs 2: Solar Elongation ( 0.0,180.0=NO ),Local Hour Angle( 0.0=NO )
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Initial FK5/J2000.0 heliocentric ecliptic osculating elements (au, days, deg.):
EPOCH= 2456593.5 != 2013-Oct-28.0000000 (CT) RMSW= n.a.
EC= .9982330942784507 QR= .811792236756687 TP= 2456649.2374139884
OM= 70.70969813975098 W= 67.17197034227108 IN= 64.0388776164782
Comet physical (GM= km^3/s^2; RAD= km):
GM= n.a. RAD= n.a.
M1= 11.9 M2= n.a. k1= 7. k2= n.a. PHCOF= n.a.
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Date__(UT)__HR:MN R.A._(ICRF/J2000.0)_DEC dRA*cosD d(DEC)/dt
*****************************************************************
$$SOE
2013-Dec-15 00:00 m 16 38 46.97 +30 10 25.0 144.9199 -102.222
2013-Dec-15 01:00 m 16 38 58.11 +30 08 42.7 144.3162 -101.976
2013-Dec-15 02:00 m 16 39 09.20 +30 07 00.6 143.6422 -101.769
2013-Dec-15 03:00 m 16 39 20.22 +30 05 18.7 142.9208 -101.610
2013-Dec-15 04:00 m 16 39 31.19 +30 03 36.9 142.1782 -101.504
2013-Dec-15 05:00 Am 16 39 42.10 +30 01 55.2 141.4419 -101.450
2013-Dec-15 06:00 N 16 39 52.95 +30 00 13.6 140.7392 -101.447
2013-Dec-15 07:00 C 16 40 03.74 +29 58 31.9 140.0949 -101.488
2013-Dec-15 08:00 * 16 40 14.49 +29 56 50.2 139.5302 -101.564
2013-Dec-15 09:00 * 16 40 25.19 +29 55 08.4 139.0606 -101.664
2013-Dec-15 10:00 * 16 40 35.86 +29 53 26.4 138.6953 -101.775
2013-Dec-15 11:00 * 16 40 46.50 +29 51 44.4 138.4365 -101.883
2013-Dec-15 12:00 * 16 40 57.12 +29 50 02.3 138.2792 -101.974
2013-Dec-15 13:00 *m 16 41 07.72 +29 48 20.1 138.2116 -102.037
2013-Dec-15 14:00 Cm 16 41 18.33 +29 46 37.8 138.2159 -102.062
2013-Dec-15 15:00 Nm 16 41 28.93 +29 44 55.5 138.2696 -102.040
2013-Dec-15 16:00 Am 16 41 39.54 +29 43 13.3 138.3467 -101.967
2013-Dec-15 17:00 m 16 41 50.14 +29 41 31.2 138.4201 -101.843
2013-Dec-15 18:00 m 16 42 00.75 +29 39 49.3 138.4629 -101.669
2013-Dec-15 19:00 m 16 42 11.36 +29 38 07.5 138.4505 -101.453
2013-Dec-15 20:00 m 16 42 21.96 +29 36 26.0 138.3621 -101.202
2013-Dec-15 21:00 m 16 42 32.55 +29 34 44.7 138.1822 -100.928
2013-Dec-15 22:00 m 16 42 43.12 +29 33 03.7 137.9018 -100.644
2013-Dec-15 23:00 m 16 42 53.66 +29 31 23.0 137.5187 -100.362
2013-Dec-16 00:00 m 16 43 04.16 +29 29 42.6 137.0378 -100.097
$$EOE
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Column meaning:
TIME
Prior to 1962, times are UT1. Dates thereafter are UTC. Any 'b' symbol in
the 1st-column denotes a B.C. date. First-column blank (" ") denotes an A.D.
date. Calendar dates prior to 1582-Oct-15 are in the Julian calendar system.
Later calendar dates are in the Gregorian system.
Time tags refer to the same instant throughout the universe, regardless of
where the observer is located.
The dynamical Coordinate Time scale is used internally. It is equivalent to
the current IAU definition of "TDB". Conversion between CT and the selected
non-uniform UT output scale has not been determined for UTC times after the
next July or January 1st. The last known leap-second is used over any future
interval.
NOTE: "n.a." in output means quantity "not available" at the print-time.
SOLAR PRESENCE (OBSERVING SITE)
Time tag is followed by a blank, then a solar-presence symbol:
'*' Daylight (refracted solar upper-limb on or above apparent horizon)
'C' Civil twilight/dawn
'N' Nautical twilight/dawn
'A' Astronomical twilight/dawn
' ' Night OR geocentric ephemeris
LUNAR PRESENCE (OBSERVING SITE)
The solar-presence symbol is immediately followed by a lunar-presence symbol:
'm' Refracted upper-limb of Moon on or above apparent horizon
' ' Refracted upper-limb of Moon below apparent horizon OR geocentric
ephemeris
R.A._(ICRF/J2000.0)_DEC =
J2000.0 astrometric right ascension and declination of target center.
Adjusted for light-time. Units: HMS (HH MM SS.ff) and DMS (DD MM SS.f)
dRA*cosD d(DEC)/dt =
The rate of change of target center apparent RA and DEC (airless).
d(RA)/dt is multiplied by the cosine of the declination.
Units: ARCSECONDS PER HOUR
