| 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) |
| 2026-09-20 00:00 |
01:31:59.03 |
-01:17:11.7 |
HIP 7028 |
34.32 |
| 2026-09-20 12:00 |
01:31:46.61 |
-01:19:14.4 |
HIP 7028 |
34.20 |
| 2026-09-21 00:00 |
01:31:34.09 |
-01:21:17.4 |
HIP 7028 |
34.47 |
| 2026-09-21 12:00 |
01:31:21.46 |
-01:23:20.5 |
HIP 7028 |
35.14 |
| 2026-09-22 00:00 |
01:31:08.73 |
-01:25:23.7 |
HIP 7028 |
36.18 |
| 2026-09-22 12:00 |
01:30:55.91 |
-01:27:27.1 |
HIP 7028 |
37.58 |
| 2026-09-23 00:00 |
01:30:42.98 |
-01:29:30.5 |
HIP 7028 |
39.30 |
| 2026-09-23 12:00 |
01:30:29.97 |
-01:31:34.1 |
HIP 6884 |
39.41 |
| 2026-09-24 00:00 |
01:30:16.86 |
-01:33:37.7 |
HIP 6884 |
38.80 |
| 2026-09-24 12:00 |
01:30:03.66 |
-01:35:41.4 |
HIP 6884 |
38.55 |
| 2026-09-25 00:00 |
01:29:50.37 |
-01:37:45.1 |
HIP 6833 |
35.96 |
| 2026-09-25 12:00 |
01:29:36.99 |
-01:39:48.8 |
HIP 6833 |
32.05 |
| 2026-09-26 00:00 |
01:29:23.52 |
-01:41:52.6 |
HIP 6833 |
28.13 |
| 2026-09-26 12:00 |
01:29:09.97 |
-01:43:56.3 |
HIP 6833 |
24.21 |
| 2026-09-27 00:00 |
01:28:56.34 |
-01:46:00.1 |
HIP 6833 |
20.28 |
| 2026-09-27 12:00 |
01:28:42.63 |
-01:48:03.8 |
HIP 6833 |
16.37 |
| 2026-09-28 00:00 |
01:28:28.84 |
-01:50:07.4 |
HIP 6833 |
12.49 |
| 2026-09-28 12:00 |
01:28:14.97 |
-01:52:11.0 |
HIP 6833 |
8.74 |
| 2026-09-29 00:00 |
01:28:01.03 |
-01:54:14.6 |
HIP 6833 |
5.40 |
| 2026-09-29 12:00 |
01:27:47.02 |
-01:56:18.0 |
HIP 6833 |
3.84 |
| 2026-09-30 00:00 |
01:27:32.93 |
-01:58:21.3 |
HIP 6833 |
5.79 |
| 2026-09-30 12:00 |
01:27:18.77 |
-02:00:24.5 |
HIP 6833 |
9.26 |
| 2026-10-01 00:00 |
01:27:04.55 |
-02:02:27.5 |
HIP 6833 |
13.12 |
| 2026-10-01 12:00 |
01:26:50.26 |
-02:04:30.4 |
HIP 6700 |
13.34 |
| 2026-10-02 00:00 |
01:26:35.90 |
-02:06:33.1 |
HIP 6700 |
9.23 |
| 2026-10-02 12:00 |
01:26:21.49 |
-02:08:35.7 |
HIP 6700 |
5.15 |
| 2026-10-03 00:00 |
01:26:07.02 |
-02:10:38.0 |
HIP 6700 |
1.43 |
| 2026-10-03 12:00 |
01:25:52.48 |
-02:12:40.1 |
HIP 6700 |
3.49 |
| 2026-10-04 00:00 |
01:25:37.90 |
-02:14:41.9 |
HIP 6700 |
7.56 |
| 2026-10-04 12:00 |
01:25:23.26 |
-02:16:43.5 |
HIP 6700 |
11.71 |
| 2026-10-05 00:00 |
01:25:08.57 |
-02:18:44.9 |
HIP 6565 |
15.32 |
| 2026-10-05 12:00 |
01:24:53.83 |
-02:20:45.9 |
HIP 6565 |
11.21 |
| 2026-10-06 00:00 |
01:24:39.04 |
-02:22:46.6 |
HIP 6565 |
7.19 |
| 2026-10-06 12:00 |
01:24:24.21 |
-02:24:47.0 |
HIP 6565 |
3.64 |
| 2026-10-07 00:00 |
01:24:09.33 |
-02:26:47.1 |
HIP 6565 |
3.23 |
| 2026-10-07 12:00 |
01:23:54.42 |
-02:28:46.8 |
HIP 6565 |
6.58 |
| 2026-10-08 00:00 |
01:23:39.47 |
-02:30:46.1 |
HIP 6565 |
10.58 |
| 2026-10-08 12:00 |
01:23:24.49 |
-02:32:45.1 |
HIP 6565 |
14.72 |
| 2026-10-09 00:00 |
01:23:09.47 |
-02:34:43.6 |
HIP 6565 |
18.91 |
| 2026-10-09 12:00 |
01:22:54.42 |
-02:36:41.7 |
HIP 6565 |
23.12 |
| 2026-10-10 00:00 |
01:22:39.35 |
-02:38:39.3 |
HIP 6565 |
27.34 |
| 2026-10-10 12:00 |
01:22:24.25 |
-02:40:36.5 |
HIP 6565 |
31.57 |
| 2026-10-11 00:00 |
01:22:09.12 |
-02:42:33.2 |
HIP 6246 |
32.94 |