| 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) |
| 2026-07-29 00:00 |
04:23:54.95 |
+42:53:21.3 |
HIP 20590 |
12.57 |
| 2026-07-29 12:00 |
04:23:56.53 |
+42:53:36.0 |
HIP 20590 |
12.60 |
| 2026-07-30 00:00 |
04:23:58.09 |
+42:53:50.7 |
HIP 20590 |
12.64 |
| 2026-07-30 12:00 |
04:23:59.62 |
+42:54:05.4 |
HIP 20590 |
12.69 |
| 2026-07-31 00:00 |
04:24:01.13 |
+42:54:20.1 |
HIP 20590 |
12.76 |
| 2026-07-31 12:00 |
04:24:02.62 |
+42:54:34.9 |
HIP 20590 |
12.84 |
| 2026-08-01 00:00 |
04:24:04.08 |
+42:54:49.7 |
HIP 20590 |
12.94 |
| 2026-08-01 12:00 |
04:24:05.52 |
+42:55:04.4 |
HIP 20590 |
13.04 |
| 2026-08-02 00:00 |
04:24:06.93 |
+42:55:19.2 |
HIP 20590 |
13.16 |
| 2026-08-02 12:00 |
04:24:08.32 |
+42:55:34.1 |
HIP 20590 |
13.28 |
| 2026-08-03 00:00 |
04:24:09.69 |
+42:55:48.9 |
HIP 20590 |
13.42 |
| 2026-08-03 12:00 |
04:24:11.03 |
+42:56:03.7 |
HIP 20590 |
13.56 |
| 2026-08-04 00:00 |
04:24:12.35 |
+42:56:18.6 |
HIP 20590 |
13.72 |
| 2026-08-04 12:00 |
04:24:13.64 |
+42:56:33.5 |
HIP 20590 |
13.88 |
| 2026-08-05 00:00 |
04:24:14.91 |
+42:56:48.3 |
HIP 20590 |
14.05 |
| 2026-08-05 12:00 |
04:24:16.15 |
+42:57:03.2 |
HIP 20590 |
14.23 |
| 2026-08-06 00:00 |
04:24:17.36 |
+42:57:18.1 |
HIP 20590 |
14.42 |
| 2026-08-06 12:00 |
04:24:18.56 |
+42:57:33.0 |
HIP 20590 |
14.61 |
| 2026-08-07 00:00 |
04:24:19.72 |
+42:57:48.0 |
HIP 20590 |
14.81 |
| 2026-08-07 12:00 |
04:24:20.86 |
+42:58:02.9 |
HIP 20590 |
15.01 |
| 2026-08-08 00:00 |
04:24:21.98 |
+42:58:17.8 |
HIP 20590 |
15.22 |
| 2026-08-08 12:00 |
04:24:23.07 |
+42:58:32.7 |
HIP 20590 |
15.43 |
| 2026-08-09 00:00 |
04:24:24.13 |
+42:58:47.7 |
HIP 20590 |
15.65 |
| 2026-08-09 12:00 |
04:24:25.17 |
+42:59:02.6 |
HIP 20590 |
15.87 |
| 2026-08-10 00:00 |
04:24:26.18 |
+42:59:17.5 |
HIP 20590 |
16.10 |
| 2026-08-10 12:00 |
04:24:27.16 |
+42:59:32.5 |
HIP 20590 |
16.33 |
| 2026-08-11 00:00 |
04:24:28.12 |
+42:59:47.4 |
HIP 20590 |
16.56 |
| 2026-08-11 12:00 |
04:24:29.05 |
+43:00:02.3 |
HIP 20590 |
16.79 |
| 2026-08-12 00:00 |
04:24:29.96 |
+43:00:17.3 |
HIP 20590 |
17.03 |
| 2026-08-12 12:00 |
04:24:30.84 |
+43:00:32.2 |
HIP 20590 |
17.27 |
| 2026-08-13 00:00 |
04:24:31.69 |
+43:00:47.1 |
HIP 20590 |
17.51 |
| 2026-08-13 12:00 |
04:24:32.51 |
+43:01:02.0 |
HIP 20590 |
17.75 |
| 2026-08-14 00:00 |
04:24:33.31 |
+43:01:16.9 |
HIP 20590 |
17.99 |
| 2026-08-14 12:00 |
04:24:34.08 |
+43:01:31.8 |
HIP 20590 |
18.24 |
| 2026-08-15 00:00 |
04:24:34.83 |
+43:01:46.7 |
HIP 20590 |
18.48 |
| 2026-08-15 12:00 |
04:24:35.54 |
+43:02:01.6 |
HIP 20590 |
18.73 |
| 2026-08-16 00:00 |
04:24:36.23 |
+43:02:16.4 |
HIP 20590 |
18.98 |
| 2026-08-16 12:00 |
04:24:36.89 |
+43:02:31.3 |
HIP 20590 |
19.22 |
| 2026-08-17 00:00 |
04:24:37.53 |
+43:02:46.1 |
HIP 20590 |
19.47 |
| 2026-08-17 12:00 |
04:24:38.13 |
+43:03:00.9 |
HIP 20590 |
19.72 |
| 2026-08-18 00:00 |
04:24:38.71 |
+43:03:15.8 |
HIP 20590 |
19.97 |
| 2026-08-18 12:00 |
04:24:39.26 |
+43:03:30.5 |
HIP 20590 |
20.22 |
| 2026-08-19 00:00 |
04:24:39.79 |
+43:03:45.3 |
HIP 20590 |
20.47 |