| Parameter |
Value |
| Designation |
283P/Spacewatch |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2013-04-06T23:45:57.098880Z |
| Orbit solution date (soln_date, UTC) |
2022-05-19T21:14:11Z |
| Obs used |
114 |
| NEO |
- |
| M1 |
16.700 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-03-13.0000000 |
| e |
0.48567912 |
| q (au) |
2.126445 |
| a (au) |
4.134471 |
| i (deg) |
14.464365 |
| Ω (om, deg) |
161.248171 |
| ω (w, deg) |
21.995380 |
| M (ma, deg) |
314.277725 |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
01:08:58.91 |
+00:24:56.2 |
HIP 5448 |
49.93 |
| 2026-05-12 12:00 |
01:09:17.31 |
+00:26:16.2 |
HIP 5448 |
47.75 |
| 2026-05-13 00:00 |
01:09:35.67 |
+00:27:35.7 |
HIP 5448 |
45.98 |
| 2026-05-13 12:00 |
01:09:53.97 |
+00:28:54.7 |
HIP 5448 |
44.66 |
| 2026-05-14 00:00 |
01:10:12.24 |
+00:30:13.0 |
HIP 5448 |
43.83 |
| 2026-05-14 12:00 |
01:10:30.45 |
+00:31:30.9 |
HIP 5647 |
40.80 |
| 2026-05-15 00:00 |
01:10:48.62 |
+00:32:48.1 |
HIP 5647 |
36.63 |
| 2026-05-15 12:00 |
01:11:06.74 |
+00:34:04.8 |
HIP 5647 |
32.62 |
| 2026-05-16 00:00 |
01:11:24.80 |
+00:35:20.9 |
HIP 5647 |
28.85 |
| 2026-05-16 12:00 |
01:11:42.82 |
+00:36:36.4 |
HIP 5647 |
25.39 |
| 2026-05-17 00:00 |
01:12:00.79 |
+00:37:51.3 |
HIP 5647 |
22.39 |
| 2026-05-17 12:00 |
01:12:18.70 |
+00:39:05.7 |
HIP 5647 |
20.06 |
| 2026-05-18 00:00 |
01:12:36.56 |
+00:40:19.4 |
HIP 5647 |
18.62 |
| 2026-05-18 12:00 |
01:12:54.37 |
+00:41:32.6 |
HIP 5647 |
18.28 |
| 2026-05-19 00:00 |
01:13:12.13 |
+00:42:45.1 |
HIP 5647 |
19.08 |
| 2026-05-19 12:00 |
01:13:29.83 |
+00:43:57.1 |
HIP 5647 |
20.89 |
| 2026-05-20 00:00 |
01:13:47.47 |
+00:45:08.4 |
HIP 5681 |
22.70 |
| 2026-05-20 12:00 |
01:14:05.06 |
+00:46:19.1 |
HIP 5886 |
24.16 |
| 2026-05-21 00:00 |
01:14:22.59 |
+00:47:29.2 |
HIP 5886 |
19.65 |
| 2026-05-21 12:00 |
01:14:40.07 |
+00:48:38.7 |
HIP 5886 |
15.17 |
| 2026-05-22 00:00 |
01:14:57.48 |
+00:49:47.5 |
HIP 5886 |
10.75 |
| 2026-05-22 12:00 |
01:15:14.84 |
+00:50:55.8 |
HIP 5886 |
6.45 |
| 2026-05-23 00:00 |
01:15:32.14 |
+00:52:03.3 |
HIP 5886 |
2.83 |
| 2026-05-23 12:00 |
01:15:49.38 |
+00:53:10.3 |
HIP 5886 |
3.78 |
| 2026-05-24 00:00 |
01:16:06.56 |
+00:54:16.6 |
HIP 5886 |
7.75 |
| 2026-05-24 12:00 |
01:16:23.68 |
+00:55:22.3 |
HIP 5886 |
12.03 |
| 2026-05-25 00:00 |
01:16:40.73 |
+00:56:27.3 |
HIP 5886 |
16.36 |
| 2026-05-25 12:00 |
01:16:57.73 |
+00:57:31.7 |
HIP 6049 |
16.11 |
| 2026-05-26 00:00 |
01:17:14.66 |
+00:58:35.4 |
HIP 6049 |
12.62 |
| 2026-05-26 12:00 |
01:17:31.53 |
+00:59:38.5 |
HIP 6049 |
9.86 |
| 2026-05-27 00:00 |
01:17:48.34 |
+01:00:40.9 |
HIP 6049 |
8.55 |
| 2026-05-27 12:00 |
01:18:05.08 |
+01:01:42.7 |
HIP 6112 |
6.75 |
| 2026-05-28 00:00 |
01:18:21.76 |
+01:02:43.8 |
HIP 6112 |
4.77 |
| 2026-05-28 12:00 |
01:18:38.37 |
+01:03:44.2 |
HIP 6112 |
6.05 |
| 2026-05-29 00:00 |
01:18:54.91 |
+01:04:44.0 |
HIP 6112 |
9.30 |
| 2026-05-29 12:00 |
01:19:11.39 |
+01:05:43.0 |
HIP 6112 |
13.12 |
| 2026-05-30 00:00 |
01:19:27.80 |
+01:06:41.4 |
HIP 6112 |
17.12 |
| 2026-05-30 12:00 |
01:19:44.14 |
+01:07:39.2 |
HIP 6112 |
21.18 |
| 2026-05-31 00:00 |
01:20:00.42 |
+01:08:36.2 |
HIP 6112 |
25.26 |
| 2026-05-31 12:00 |
01:20:16.62 |
+01:09:32.5 |
HIP 6112 |
29.35 |
| 2026-06-01 00:00 |
01:20:32.76 |
+01:10:28.2 |
HIP 6112 |
33.44 |
| 2026-06-01 12:00 |
01:20:48.83 |
+01:11:23.2 |
HIP 6112 |
37.52 |
| 2026-06-02 00:00 |
01:21:04.82 |
+01:12:17.4 |
HIP 6432 |
38.85 |