| Parameter |
Value |
| Designation |
C/2000 OF8 (Spacewatch) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2001-08-04T19:13:02.890560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:05Z |
| Obs used |
72 |
| NEO |
- |
| M1 |
12.800 |
| K1 |
4.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2000-09-24.0000000 |
| e |
1.00180402 |
| q (au) |
2.172785 |
| a (au) |
-1204.412900 |
| i (deg) |
152.432608 |
| Ω (om, deg) |
117.090492 |
| ω (w, deg) |
256.080338 |
| M (ma, deg) |
-0.007423 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.880 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.880 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.800 |
| 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 |
04:24:13.79 |
+43:18:08.2 |
HIP 20575 |
17.97 |
| 2026-09-20 12:00 |
04:24:12.45 |
+43:18:19.7 |
HIP 20575 |
17.82 |
| 2026-09-21 00:00 |
04:24:11.08 |
+43:18:31.1 |
HIP 20575 |
17.67 |
| 2026-09-21 12:00 |
04:24:09.68 |
+43:18:42.4 |
HIP 20575 |
17.53 |
| 2026-09-22 00:00 |
04:24:08.25 |
+43:18:53.6 |
HIP 20575 |
17.40 |
| 2026-09-22 12:00 |
04:24:06.79 |
+43:19:04.7 |
HIP 20575 |
17.27 |
| 2026-09-23 00:00 |
04:24:05.31 |
+43:19:15.7 |
HIP 20575 |
17.15 |
| 2026-09-23 12:00 |
04:24:03.80 |
+43:19:26.7 |
HIP 20575 |
17.04 |
| 2026-09-24 00:00 |
04:24:02.26 |
+43:19:37.5 |
HIP 20575 |
16.94 |
| 2026-09-24 12:00 |
04:24:00.69 |
+43:19:48.3 |
HIP 20433 |
16.74 |
| 2026-09-25 00:00 |
04:23:59.10 |
+43:19:58.9 |
HIP 20433 |
16.40 |
| 2026-09-25 12:00 |
04:23:57.48 |
+43:20:09.5 |
HIP 20433 |
16.06 |
| 2026-09-26 00:00 |
04:23:55.83 |
+43:20:20.0 |
HIP 20433 |
15.71 |
| 2026-09-26 12:00 |
04:23:54.15 |
+43:20:30.4 |
HIP 20433 |
15.36 |
| 2026-09-27 00:00 |
04:23:52.45 |
+43:20:40.7 |
HIP 20433 |
15.01 |
| 2026-09-27 12:00 |
04:23:50.72 |
+43:20:50.9 |
HIP 20433 |
14.65 |
| 2026-09-28 00:00 |
04:23:48.96 |
+43:21:01.0 |
HIP 20433 |
14.29 |
| 2026-09-28 12:00 |
04:23:47.18 |
+43:21:11.0 |
HIP 20433 |
13.93 |
| 2026-09-29 00:00 |
04:23:45.37 |
+43:21:20.9 |
HIP 20433 |
13.56 |
| 2026-09-29 12:00 |
04:23:43.53 |
+43:21:30.7 |
HIP 20433 |
13.19 |
| 2026-09-30 00:00 |
04:23:41.66 |
+43:21:40.5 |
HIP 20433 |
12.81 |
| 2026-09-30 12:00 |
04:23:39.77 |
+43:21:50.1 |
HIP 20433 |
12.43 |
| 2026-10-01 00:00 |
04:23:37.86 |
+43:21:59.6 |
HIP 20433 |
12.05 |
| 2026-10-01 12:00 |
04:23:35.91 |
+43:22:09.0 |
HIP 20433 |
11.67 |
| 2026-10-02 00:00 |
04:23:33.94 |
+43:22:18.3 |
HIP 20433 |
11.27 |
| 2026-10-02 12:00 |
04:23:31.95 |
+43:22:27.5 |
HIP 20433 |
10.88 |
| 2026-10-03 00:00 |
04:23:29.92 |
+43:22:36.6 |
HIP 20433 |
10.48 |
| 2026-10-03 12:00 |
04:23:27.88 |
+43:22:45.6 |
HIP 20433 |
10.08 |
| 2026-10-04 00:00 |
04:23:25.80 |
+43:22:54.4 |
HIP 20433 |
9.68 |
| 2026-10-04 12:00 |
04:23:23.70 |
+43:23:03.2 |
HIP 20433 |
9.27 |
| 2026-10-05 00:00 |
04:23:21.58 |
+43:23:11.9 |
HIP 20433 |
8.86 |
| 2026-10-05 12:00 |
04:23:19.43 |
+43:23:20.4 |
HIP 20433 |
8.45 |
| 2026-10-06 00:00 |
04:23:17.25 |
+43:23:28.9 |
HIP 20433 |
8.03 |
| 2026-10-06 12:00 |
04:23:15.05 |
+43:23:37.2 |
HIP 20433 |
7.61 |
| 2026-10-07 00:00 |
04:23:12.82 |
+43:23:45.4 |
HIP 20433 |
7.19 |
| 2026-10-07 12:00 |
04:23:10.57 |
+43:23:53.5 |
HIP 20433 |
6.76 |
| 2026-10-08 00:00 |
04:23:08.29 |
+43:24:01.5 |
HIP 20433 |
6.33 |
| 2026-10-08 12:00 |
04:23:05.99 |
+43:24:09.4 |
HIP 20433 |
5.90 |
| 2026-10-09 00:00 |
04:23:03.66 |
+43:24:17.1 |
HIP 20433 |
5.47 |
| 2026-10-09 12:00 |
04:23:01.31 |
+43:24:24.8 |
HIP 20433 |
5.03 |
| 2026-10-10 00:00 |
04:22:58.94 |
+43:24:32.3 |
HIP 20433 |
4.60 |
| 2026-10-10 12:00 |
04:22:56.54 |
+43:24:39.7 |
HIP 20433 |
4.17 |
| 2026-10-11 00:00 |
04:22:54.12 |
+43:24:47.0 |
HIP 20433 |
3.73 |