| Parameter |
Value |
| Designation |
366P/Spacewatch |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-01-05T10:45:06.180480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:37Z |
| Obs used |
74 |
| NEO |
- |
| M1 |
13.100 |
| K1 |
17.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-03-17T04:21:57.024000Z |
| Discovery magnitude (MPC) |
20.20 N |
| Discovery observatory (MPC) |
J04 · ESA Optical Ground Station, Tenerife |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2010-05-04.0000000 |
| e |
0.34736448 |
| q (au) |
2.284924 |
| a (au) |
3.501073 |
| i (deg) |
8.853746 |
| Ω (om, deg) |
70.797085 |
| ω (w, deg) |
153.581562 |
| M (ma, deg) |
268.005489 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.631 + 4.779\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.631 |
| n |
4.779 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
1.000 |
| 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 |
23:48:57.55 |
-10:36:09.7 |
HIP 117528 |
34.42 |
| 2026-06-01 12:00 |
23:49:18.87 |
-10:35:00.7 |
HIP 117528 |
33.26 |
| 2026-06-02 00:00 |
23:49:40.02 |
-10:33:53.0 |
HIP 117528 |
32.93 |
| 2026-06-02 12:00 |
23:50:01.00 |
-10:32:46.8 |
HIP 117528 |
33.43 |
| 2026-06-03 00:00 |
23:50:21.79 |
-10:31:41.9 |
HIP 117541 |
33.29 |
| 2026-06-03 12:00 |
23:50:42.41 |
-10:30:38.4 |
HIP 117541 |
32.90 |
| 2026-06-04 00:00 |
23:51:02.85 |
-10:29:36.4 |
HIP 117541 |
33.33 |
| 2026-06-04 12:00 |
23:51:23.11 |
-10:28:35.7 |
HIP 117541 |
34.52 |
| 2026-06-05 00:00 |
23:51:43.19 |
-10:27:36.5 |
HIP 117541 |
36.39 |
| 2026-06-05 12:00 |
23:52:03.09 |
-10:26:38.6 |
HIP 117789 |
38.36 |
| 2026-06-06 00:00 |
23:52:22.81 |
-10:25:42.2 |
HIP 117789 |
37.32 |
| 2026-06-06 12:00 |
23:52:42.34 |
-10:24:47.3 |
HIP 117789 |
36.90 |
| 2026-06-07 00:00 |
23:53:01.68 |
-10:23:53.8 |
HIP 117789 |
37.10 |
| 2026-06-07 12:00 |
23:53:20.84 |
-10:23:01.7 |
HIP 117789 |
37.89 |
| 2026-06-08 00:00 |
23:53:39.81 |
-10:22:11.1 |
HIP 117964 |
38.49 |
| 2026-06-08 12:00 |
23:53:58.59 |
-10:21:22.0 |
HIP 117964 |
35.73 |
| 2026-06-09 00:00 |
23:54:17.18 |
-10:20:34.3 |
HIP 117964 |
33.42 |
| 2026-06-09 12:00 |
23:54:35.58 |
-10:19:48.2 |
HIP 117964 |
31.62 |
| 2026-06-10 00:00 |
23:54:53.79 |
-10:19:03.5 |
HIP 117964 |
30.40 |
| 2026-06-10 12:00 |
23:55:11.81 |
-10:18:20.3 |
HIP 117964 |
29.82 |
| 2026-06-11 00:00 |
23:55:29.63 |
-10:17:38.6 |
HIP 117964 |
29.88 |
| 2026-06-11 12:00 |
23:55:47.25 |
-10:16:58.4 |
HIP 117964 |
30.57 |
| 2026-06-12 00:00 |
23:56:04.68 |
-10:16:19.7 |
HIP 117964 |
31.81 |
| 2026-06-12 12:00 |
23:56:21.91 |
-10:15:42.6 |
HIP 117964 |
33.53 |
| 2026-06-13 00:00 |
23:56:38.93 |
-10:15:07.0 |
HIP 117964 |
35.64 |
| 2026-06-13 12:00 |
23:56:55.76 |
-10:14:32.9 |
HIP 118115 |
36.89 |
| 2026-06-14 00:00 |
23:57:12.39 |
-10:14:00.3 |
HIP 118115 |
35.55 |
| 2026-06-14 12:00 |
23:57:28.81 |
-10:13:29.3 |
HIP 118115 |
34.68 |
| 2026-06-15 00:00 |
23:57:45.03 |
-10:12:59.9 |
HIP 118115 |
34.29 |
| 2026-06-15 12:00 |
23:58:01.04 |
-10:12:32.0 |
HIP 118115 |
34.39 |
| 2026-06-16 00:00 |
23:58:16.84 |
-10:12:05.7 |
HIP 33 |
34.93 |
| 2026-06-16 12:00 |
23:58:32.44 |
-10:11:40.9 |
HIP 33 |
31.75 |
| 2026-06-17 00:00 |
23:58:47.83 |
-10:11:17.7 |
HIP 33 |
28.77 |
| 2026-06-17 12:00 |
23:59:03.00 |
-10:10:56.1 |
HIP 33 |
26.03 |
| 2026-06-18 00:00 |
23:59:17.97 |
-10:10:36.0 |
HIP 33 |
23.58 |
| 2026-06-18 12:00 |
23:59:32.73 |
-10:10:17.5 |
HIP 33 |
21.51 |
| 2026-06-19 00:00 |
23:59:47.27 |
-10:10:00.6 |
HIP 33 |
19.88 |
| 2026-06-19 12:00 |
00:00:01.60 |
-10:09:45.3 |
HIP 33 |
18.80 |
| 2026-06-20 00:00 |
00:00:15.71 |
-10:09:31.5 |
HIP 33 |
18.33 |
| 2026-06-20 12:00 |
00:00:29.61 |
-10:09:19.4 |
HIP 33 |
18.48 |
| 2026-06-21 00:00 |
00:00:43.29 |
-10:09:08.8 |
HIP 33 |
19.21 |
| 2026-06-21 12:00 |
00:00:56.75 |
-10:08:59.9 |
HIP 33 |
20.43 |
| 2026-06-22 00:00 |
00:01:10.00 |
-10:08:52.5 |
HIP 33 |
22.03 |