| 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) |
| 2026-06-01 00:00 |
04:18:56.06 |
+42:31:00.8 |
HIP 20155 |
8.72 |
| 2026-06-01 12:00 |
04:18:59.20 |
+42:31:07.7 |
HIP 20155 |
8.64 |
| 2026-06-02 00:00 |
04:19:02.33 |
+42:31:14.7 |
HIP 20155 |
8.60 |
| 2026-06-02 12:00 |
04:19:05.47 |
+42:31:21.8 |
HIP 20155 |
8.60 |
| 2026-06-03 00:00 |
04:19:08.60 |
+42:31:29.0 |
HIP 20155 |
8.64 |
| 2026-06-03 12:00 |
04:19:11.73 |
+42:31:36.4 |
HIP 20155 |
8.73 |
| 2026-06-04 00:00 |
04:19:14.85 |
+42:31:43.8 |
HIP 20155 |
8.86 |
| 2026-06-04 12:00 |
04:19:17.97 |
+42:31:51.3 |
HIP 20155 |
9.02 |
| 2026-06-05 00:00 |
04:19:21.09 |
+42:31:58.9 |
HIP 20155 |
9.22 |
| 2026-06-05 12:00 |
04:19:24.21 |
+42:32:06.7 |
HIP 20155 |
9.46 |
| 2026-06-06 00:00 |
04:19:27.32 |
+42:32:14.5 |
HIP 20155 |
9.72 |
| 2026-06-06 12:00 |
04:19:30.43 |
+42:32:22.4 |
HIP 20155 |
10.02 |
| 2026-06-07 00:00 |
04:19:33.54 |
+42:32:30.4 |
HIP 20155 |
10.34 |
| 2026-06-07 12:00 |
04:19:36.64 |
+42:32:38.5 |
HIP 20155 |
10.68 |
| 2026-06-08 00:00 |
04:19:39.73 |
+42:32:46.8 |
HIP 20155 |
11.05 |
| 2026-06-08 12:00 |
04:19:42.83 |
+42:32:55.1 |
HIP 20155 |
11.44 |
| 2026-06-09 00:00 |
04:19:45.91 |
+42:33:03.5 |
HIP 20155 |
11.84 |
| 2026-06-09 12:00 |
04:19:48.99 |
+42:33:12.0 |
HIP 20155 |
12.26 |
| 2026-06-10 00:00 |
04:19:52.07 |
+42:33:20.6 |
HIP 20155 |
12.69 |
| 2026-06-10 12:00 |
04:19:55.14 |
+42:33:29.3 |
HIP 20155 |
13.14 |
| 2026-06-11 00:00 |
04:19:58.21 |
+42:33:38.1 |
HIP 20155 |
13.60 |
| 2026-06-11 12:00 |
04:20:01.27 |
+42:33:47.0 |
HIP 20155 |
14.06 |
| 2026-06-12 00:00 |
04:20:04.32 |
+42:33:56.0 |
HIP 20155 |
14.54 |
| 2026-06-12 12:00 |
04:20:07.37 |
+42:34:05.0 |
HIP 20155 |
15.02 |
| 2026-06-13 00:00 |
04:20:10.41 |
+42:34:14.2 |
HIP 20245 |
15.42 |
| 2026-06-13 12:00 |
04:20:13.44 |
+42:34:23.5 |
HIP 20245 |
15.54 |
| 2026-06-14 00:00 |
04:20:16.47 |
+42:34:32.8 |
HIP 20245 |
15.68 |
| 2026-06-14 12:00 |
04:20:19.48 |
+42:34:42.2 |
HIP 20245 |
15.85 |
| 2026-06-15 00:00 |
04:20:22.50 |
+42:34:51.8 |
HIP 20245 |
16.03 |
| 2026-06-15 12:00 |
04:20:25.50 |
+42:35:01.4 |
HIP 20245 |
16.24 |
| 2026-06-16 00:00 |
04:20:28.49 |
+42:35:11.1 |
HIP 20245 |
16.46 |
| 2026-06-16 12:00 |
04:20:31.48 |
+42:35:20.9 |
HIP 20245 |
16.71 |
| 2026-06-17 00:00 |
04:20:34.46 |
+42:35:30.8 |
HIP 20245 |
16.97 |
| 2026-06-17 12:00 |
04:20:37.43 |
+42:35:40.7 |
HIP 20245 |
17.24 |
| 2026-06-18 00:00 |
04:20:40.39 |
+42:35:50.8 |
HIP 20245 |
17.53 |
| 2026-06-18 12:00 |
04:20:43.34 |
+42:36:00.9 |
HIP 20245 |
17.84 |
| 2026-06-19 00:00 |
04:20:46.29 |
+42:36:11.2 |
HIP 20245 |
18.16 |
| 2026-06-19 12:00 |
04:20:49.22 |
+42:36:21.5 |
HIP 20245 |
18.49 |
| 2026-06-20 00:00 |
04:20:52.14 |
+42:36:31.9 |
HIP 20245 |
18.83 |
| 2026-06-20 12:00 |
04:20:55.06 |
+42:36:42.3 |
HIP 20245 |
19.19 |
| 2026-06-21 00:00 |
04:20:57.96 |
+42:36:52.9 |
HIP 20245 |
19.55 |
| 2026-06-21 12:00 |
04:21:00.85 |
+42:37:03.5 |
HIP 20245 |
19.93 |
| 2026-06-22 00:00 |
04:21:03.74 |
+42:37:14.2 |
HIP 20245 |
20.31 |