C/2002 O4 (Hoenig)
| Parameter |
Value |
| Designation |
C/2002 O4 (Hoenig) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2002-10-01T23:33:55.399680Z |
| Orbit solution date (soln_date, UTC) |
2021-11-20T19:12:51Z |
| Obs used |
1195 |
| NEO |
- |
| M1 |
13.300 |
| K1 |
8.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2002-08-13.0000000 |
| e |
1.00085552 |
| q (au) |
0.776209 |
| a (au) |
-907.293712 |
| i (deg) |
73.126827 |
| Ω (om, deg) |
321.040639 |
| ω (w, deg) |
105.936774 |
| M (ma, deg) |
-0.001803 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.577 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.577 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
10.000 |
| 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 |
| 2002-07-22 |
2002-08-14 |
+37.8142 |
-4.484 |
| 2002-08-14 |
2002-10-01 |
-12.0631 |
+0.022 |
| 2002-10-05 |
2002-11-06 |
+10.6192 |
+2.598 |
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 |
09:03:13.58 |
-77:22:02.5 |
HIP 44772 |
27.30 |
| 2026-02-03 12:00 |
09:03:01.94 |
-77:22:04.1 |
HIP 44772 |
27.66 |
| 2026-02-04 00:00 |
09:02:50.30 |
-77:22:05.2 |
HIP 44772 |
28.03 |
| 2026-02-04 12:00 |
09:02:38.66 |
-77:22:06.0 |
HIP 44772 |
28.41 |
| 2026-02-05 00:00 |
09:02:27.02 |
-77:22:06.4 |
HIP 43762 |
28.45 |
| 2026-02-05 12:00 |
09:02:15.38 |
-77:22:06.5 |
HIP 43762 |
27.90 |
| 2026-02-06 00:00 |
09:02:03.75 |
-77:22:06.1 |
HIP 43762 |
27.37 |
| 2026-02-06 12:00 |
09:01:52.13 |
-77:22:05.4 |
HIP 43762 |
26.84 |
| 2026-02-07 00:00 |
09:01:40.51 |
-77:22:04.3 |
HIP 43762 |
26.32 |
| 2026-02-07 12:00 |
09:01:28.91 |
-77:22:02.9 |
HIP 43762 |
25.80 |
| 2026-02-08 00:00 |
09:01:17.31 |
-77:22:01.0 |
HIP 43762 |
25.30 |
| 2026-02-08 12:00 |
09:01:05.72 |
-77:21:58.8 |
HIP 43762 |
24.81 |
| 2026-02-09 00:00 |
09:00:54.15 |
-77:21:56.2 |
HIP 43762 |
24.33 |
| 2026-02-09 12:00 |
09:00:42.58 |
-77:21:53.3 |
HIP 43762 |
23.86 |
| 2026-02-10 00:00 |
09:00:31.04 |
-77:21:49.9 |
HIP 43762 |
23.40 |
| 2026-02-10 12:00 |
09:00:19.50 |
-77:21:46.2 |
HIP 43762 |
22.95 |
| 2026-02-11 00:00 |
09:00:07.99 |
-77:21:42.1 |
HIP 43762 |
22.52 |
| 2026-02-11 12:00 |
08:59:56.49 |
-77:21:37.7 |
HIP 43762 |
22.10 |
| 2026-02-12 00:00 |
08:59:45.01 |
-77:21:32.8 |
HIP 43762 |
21.69 |
| 2026-02-12 12:00 |
08:59:33.55 |
-77:21:27.6 |
HIP 43762 |
21.30 |
| 2026-02-13 00:00 |
08:59:22.11 |
-77:21:22.0 |
HIP 43762 |
20.93 |
| 2026-02-13 12:00 |
08:59:10.70 |
-77:21:16.1 |
HIP 43762 |
20.58 |
| 2026-02-14 00:00 |
08:58:59.30 |
-77:21:09.8 |
HIP 43762 |
20.24 |
| 2026-02-14 12:00 |
08:58:47.94 |
-77:21:03.1 |
HIP 43762 |
19.93 |
| 2026-02-15 00:00 |
08:58:36.60 |
-77:20:56.0 |
HIP 43762 |
19.63 |
| 2026-02-15 12:00 |
08:58:25.28 |
-77:20:48.6 |
HIP 43762 |
19.36 |
| 2026-02-16 00:00 |
08:58:14.00 |
-77:20:40.8 |
HIP 43762 |
19.10 |
| 2026-02-16 12:00 |
08:58:02.74 |
-77:20:32.7 |
HIP 43762 |
18.88 |
| 2026-02-17 00:00 |
08:57:51.51 |
-77:20:24.1 |
HIP 43762 |
18.67 |
| 2026-02-17 12:00 |
08:57:40.32 |
-77:20:15.2 |
HIP 43762 |
18.49 |
| 2026-02-18 00:00 |
08:57:29.16 |
-77:20:06.0 |
HIP 43762 |
18.34 |
| 2026-02-18 12:00 |
08:57:18.03 |
-77:19:56.4 |
HIP 43762 |
18.21 |
| 2026-02-19 00:00 |
08:57:06.93 |
-77:19:46.4 |
HIP 43762 |
18.11 |
| 2026-02-19 12:00 |
08:56:55.88 |
-77:19:36.1 |
HIP 43762 |
18.04 |
| 2026-02-20 00:00 |
08:56:44.86 |
-77:19:25.4 |
HIP 43762 |
17.99 |
| 2026-02-20 12:00 |
08:56:33.88 |
-77:19:14.3 |
HIP 43762 |
17.97 |
| 2026-02-21 00:00 |
08:56:22.94 |
-77:19:02.9 |
HIP 43762 |
17.98 |
| 2026-02-21 12:00 |
08:56:12.04 |
-77:18:51.2 |
HIP 43762 |
18.02 |
| 2026-02-22 00:00 |
08:56:01.18 |
-77:18:39.0 |
HIP 43762 |
18.09 |
| 2026-02-22 12:00 |
08:55:50.36 |
-77:18:26.6 |
HIP 43762 |
18.18 |
| 2026-02-23 00:00 |
08:55:39.59 |
-77:18:13.8 |
HIP 43762 |
18.30 |
| 2026-02-23 12:00 |
08:55:28.86 |
-77:18:00.6 |
HIP 43762 |
18.44 |
| 2026-02-24 00:00 |
08:55:18.18 |
-77:17:47.1 |
HIP 43762 |
18.61 |