C/2002 X1 (LINEAR)
| Parameter |
Value |
| Designation |
C/2002 X1 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2003-07-12T21:19:27.825600Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:24Z |
| Obs used |
1432 |
| NEO |
- |
| M1 |
12.400 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2003-04-21.0000000 |
| e |
0.99818758 |
| q (au) |
2.486699 |
| a (au) |
1372.033208 |
| i (deg) |
164.089428 |
| Ω (om, deg) |
281.887134 |
| ω (w, deg) |
207.325128 |
| M (ma, deg) |
359.998392 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.579 + 2.717\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.579 |
| n |
2.717 |
| gf |
1.000 |
| gb |
-0.681 |
| k |
0.995 |
| δ90 |
9.999 |
| Parameter |
Symbol |
Range |
Description |
| Absolute magnitude at 1 AU from Sun and Earth |
H0 |
-5 to 20 |
Intrinsic brightness of the comet |
| Photometric slope parameter |
n |
2 to 6 |
Rate of brightness change with heliocentric distance |
| Forward scattering asymmetry factor |
gf |
0.8 to 1 |
Degree of forward scattering |
| Backward scattering asymmetry factor |
gb |
-1 to -0.5 |
Degree of backward scattering |
| Partitioning coefficient |
k |
0.8 to 1 |
Ratio between forward/backward scattering contributions |
| Dust-to-gas brightness ratio |
δ90 |
1 to 10 |
Relative contribution of dust scattering to gas emission |
Reference: EPSC-DPS2025-160
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2002-02-21 |
2003-05-02 |
-0.1664 |
-0.115 |
| 2003-08-03 |
2004-01-17 |
+21.3196 |
-9.226 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
18:56:46.16 |
-22:55:28.7 |
HIP 92980 |
13.71 |
| 2026-02-03 12:00 |
18:56:48.58 |
-22:55:24.9 |
HIP 92980 |
13.90 |
| 2026-02-04 00:00 |
18:56:51.00 |
-22:55:21.0 |
HIP 92980 |
14.10 |
| 2026-02-04 12:00 |
18:56:53.39 |
-22:55:17.2 |
HIP 92980 |
14.33 |
| 2026-02-05 00:00 |
18:56:55.78 |
-22:55:13.5 |
HIP 92980 |
14.56 |
| 2026-02-05 12:00 |
18:56:58.15 |
-22:55:09.7 |
HIP 92980 |
14.82 |
| 2026-02-06 00:00 |
18:57:00.51 |
-22:55:05.9 |
HIP 92980 |
15.09 |
| 2026-02-06 12:00 |
18:57:02.85 |
-22:55:02.2 |
HIP 92980 |
15.37 |
| 2026-02-07 00:00 |
18:57:05.18 |
-22:54:58.5 |
HIP 92980 |
15.66 |
| 2026-02-07 12:00 |
18:57:07.49 |
-22:54:54.8 |
HIP 92980 |
15.97 |
| 2026-02-08 00:00 |
18:57:09.79 |
-22:54:51.1 |
HIP 92980 |
16.28 |
| 2026-02-08 12:00 |
18:57:12.08 |
-22:54:47.5 |
HIP 92980 |
16.60 |
| 2026-02-09 00:00 |
18:57:14.35 |
-22:54:43.8 |
HIP 92980 |
16.94 |
| 2026-02-09 12:00 |
18:57:16.60 |
-22:54:40.2 |
HIP 92980 |
17.27 |
| 2026-02-10 00:00 |
18:57:18.84 |
-22:54:36.6 |
HIP 92980 |
17.62 |
| 2026-02-10 12:00 |
18:57:21.07 |
-22:54:33.0 |
HIP 92980 |
17.97 |
| 2026-02-11 00:00 |
18:57:23.28 |
-22:54:29.5 |
HIP 92980 |
18.33 |
| 2026-02-11 12:00 |
18:57:25.47 |
-22:54:25.9 |
HIP 92980 |
18.69 |
| 2026-02-12 00:00 |
18:57:27.64 |
-22:54:22.4 |
HIP 92980 |
19.05 |
| 2026-02-12 12:00 |
18:57:29.80 |
-22:54:18.9 |
HIP 92980 |
19.42 |
| 2026-02-13 00:00 |
18:57:31.95 |
-22:54:15.5 |
HIP 92980 |
19.80 |
| 2026-02-13 12:00 |
18:57:34.07 |
-22:54:12.0 |
HIP 93155 |
19.50 |
| 2026-02-14 00:00 |
18:57:36.18 |
-22:54:08.6 |
HIP 93155 |
19.14 |
| 2026-02-14 12:00 |
18:57:38.27 |
-22:54:05.2 |
HIP 93155 |
18.78 |
| 2026-02-15 00:00 |
18:57:40.35 |
-22:54:01.8 |
HIP 93155 |
18.43 |
| 2026-02-15 12:00 |
18:57:42.41 |
-22:53:58.4 |
HIP 93155 |
18.09 |
| 2026-02-16 00:00 |
18:57:44.45 |
-22:53:55.1 |
HIP 93155 |
17.76 |
| 2026-02-16 12:00 |
18:57:46.47 |
-22:53:51.7 |
HIP 93155 |
17.43 |
| 2026-02-17 00:00 |
18:57:48.48 |
-22:53:48.4 |
HIP 93155 |
17.12 |
| 2026-02-17 12:00 |
18:57:50.46 |
-22:53:45.2 |
HIP 93155 |
16.82 |
| 2026-02-18 00:00 |
18:57:52.43 |
-22:53:41.9 |
HIP 93155 |
16.53 |
| 2026-02-18 12:00 |
18:57:54.38 |
-22:53:38.7 |
HIP 93155 |
16.24 |
| 2026-02-19 00:00 |
18:57:56.31 |
-22:53:35.5 |
HIP 93155 |
15.97 |
| 2026-02-19 12:00 |
18:57:58.22 |
-22:53:32.3 |
HIP 93155 |
15.71 |
| 2026-02-20 00:00 |
18:58:00.12 |
-22:53:29.2 |
HIP 93155 |
15.46 |
| 2026-02-20 12:00 |
18:58:01.99 |
-22:53:26.0 |
HIP 93155 |
15.22 |
| 2026-02-21 00:00 |
18:58:03.85 |
-22:53:22.9 |
HIP 93155 |
14.99 |
| 2026-02-21 12:00 |
18:58:05.68 |
-22:53:19.9 |
HIP 93155 |
14.77 |
| 2026-02-22 00:00 |
18:58:07.50 |
-22:53:16.8 |
HIP 93155 |
14.56 |
| 2026-02-22 12:00 |
18:58:09.30 |
-22:53:13.8 |
HIP 93155 |
14.37 |
| 2026-02-23 00:00 |
18:58:11.07 |
-22:53:10.8 |
HIP 93155 |
14.18 |
| 2026-02-23 12:00 |
18:58:12.83 |
-22:53:07.8 |
HIP 93155 |
14.01 |
| 2026-02-24 00:00 |
18:58:14.57 |
-22:53:04.9 |
HIP 93155 |
13.85 |