| Parameter |
Value |
| Designation |
C/2005 O2 (Christensen) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2005-09-08T10:41:22.672320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:51Z |
| Obs used |
126 |
| NEO |
- |
| M1 |
5.200 |
| K1 |
20.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2005-09-25.0000000 |
| e |
0.85937661 |
| q (au) |
3.333576 |
| a (au) |
23.705702 |
| i (deg) |
148.892051 |
| Ω (om, deg) |
280.771395 |
| ω (w, deg) |
263.833891 |
| M (ma, deg) |
0.141366 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.164 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.164 |
| n |
6.000 |
| gf |
0.999 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
15:03:56.33 |
+10:36:26.9 |
HIP 73713 |
7.88 |
| 2026-09-20 12:00 |
15:03:58.40 |
+10:36:00.4 |
HIP 73713 |
8.21 |
| 2026-09-21 00:00 |
15:04:00.49 |
+10:35:34.1 |
HIP 73713 |
8.58 |
| 2026-09-21 12:00 |
15:04:02.60 |
+10:35:07.8 |
HIP 73713 |
8.98 |
| 2026-09-22 00:00 |
15:04:04.74 |
+10:34:41.5 |
HIP 73713 |
9.42 |
| 2026-09-22 12:00 |
15:04:06.90 |
+10:34:15.3 |
HIP 73713 |
9.88 |
| 2026-09-23 00:00 |
15:04:09.08 |
+10:33:49.2 |
HIP 73713 |
10.37 |
| 2026-09-23 12:00 |
15:04:11.29 |
+10:33:23.2 |
HIP 73713 |
10.88 |
| 2026-09-24 00:00 |
15:04:13.51 |
+10:32:57.2 |
HIP 73713 |
11.40 |
| 2026-09-24 12:00 |
15:04:15.76 |
+10:32:31.3 |
HIP 73713 |
11.95 |
| 2026-09-25 00:00 |
15:04:18.03 |
+10:32:05.4 |
HIP 73713 |
12.51 |
| 2026-09-25 12:00 |
15:04:20.33 |
+10:31:39.7 |
HIP 73713 |
13.09 |
| 2026-09-26 00:00 |
15:04:22.64 |
+10:31:14.0 |
HIP 73713 |
13.68 |
| 2026-09-26 12:00 |
15:04:24.98 |
+10:30:48.4 |
HIP 73713 |
14.28 |
| 2026-09-27 00:00 |
15:04:27.33 |
+10:30:22.9 |
HIP 73713 |
14.89 |
| 2026-09-27 12:00 |
15:04:29.71 |
+10:29:57.5 |
HIP 73713 |
15.51 |
| 2026-09-28 00:00 |
15:04:32.11 |
+10:29:32.1 |
HIP 73713 |
16.14 |
| 2026-09-28 12:00 |
15:04:34.53 |
+10:29:06.9 |
HIP 73713 |
16.78 |
| 2026-09-29 00:00 |
15:04:36.97 |
+10:28:41.7 |
HIP 73713 |
17.43 |
| 2026-09-29 12:00 |
15:04:39.43 |
+10:28:16.6 |
HIP 73713 |
18.08 |
| 2026-09-30 00:00 |
15:04:41.91 |
+10:27:51.6 |
HIP 73713 |
18.75 |
| 2026-09-30 12:00 |
15:04:44.41 |
+10:27:26.7 |
HIP 73713 |
19.41 |
| 2026-10-01 00:00 |
15:04:46.93 |
+10:27:01.9 |
HIP 73713 |
20.09 |
| 2026-10-01 12:00 |
15:04:49.47 |
+10:26:37.2 |
HIP 73713 |
20.77 |
| 2026-10-02 00:00 |
15:04:52.03 |
+10:26:12.6 |
HIP 73713 |
21.46 |
| 2026-10-02 12:00 |
15:04:54.61 |
+10:25:48.1 |
HIP 73713 |
22.15 |
| 2026-10-03 00:00 |
15:04:57.21 |
+10:25:23.7 |
HIP 73713 |
22.85 |
| 2026-10-03 12:00 |
15:04:59.83 |
+10:24:59.4 |
HIP 73713 |
23.55 |
| 2026-10-04 00:00 |
15:05:02.46 |
+10:24:35.2 |
HIP 73713 |
24.26 |
| 2026-10-04 12:00 |
15:05:05.12 |
+10:24:11.1 |
HIP 73713 |
24.97 |
| 2026-10-05 00:00 |
15:05:07.79 |
+10:23:47.1 |
HIP 73818 |
25.12 |
| 2026-10-05 12:00 |
15:05:10.48 |
+10:23:23.2 |
HIP 73818 |
24.68 |
| 2026-10-06 00:00 |
15:05:13.19 |
+10:22:59.5 |
HIP 73818 |
24.27 |
| 2026-10-06 12:00 |
15:05:15.92 |
+10:22:35.8 |
HIP 73818 |
23.87 |
| 2026-10-07 00:00 |
15:05:18.66 |
+10:22:12.3 |
HIP 73818 |
23.50 |
| 2026-10-07 12:00 |
15:05:21.43 |
+10:21:48.9 |
HIP 73818 |
23.15 |
| 2026-10-08 00:00 |
15:05:24.21 |
+10:21:25.6 |
HIP 73818 |
22.82 |
| 2026-10-08 12:00 |
15:05:27.00 |
+10:21:02.5 |
HIP 73818 |
22.52 |
| 2026-10-09 00:00 |
15:05:29.82 |
+10:20:39.4 |
HIP 73818 |
22.25 |
| 2026-10-09 12:00 |
15:05:32.65 |
+10:20:16.5 |
HIP 73818 |
22.00 |
| 2026-10-10 00:00 |
15:05:35.49 |
+10:19:53.7 |
HIP 73818 |
21.78 |
| 2026-10-10 12:00 |
15:05:38.36 |
+10:19:31.1 |
HIP 73818 |
21.59 |
| 2026-10-11 00:00 |
15:05:41.23 |
+10:19:08.6 |
HIP 73818 |
21.44 |