| Parameter |
Value |
| Designation |
C/1992 J1 (Spacewatch) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1993-09-05T13:00:26.484480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:41Z |
| Obs used |
240 |
| NEO |
- |
| M1 |
8.300 |
| K1 |
9.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1993-08-03.0000000 |
| e |
0.99997349 |
| q (au) |
3.007011 |
| a (au) |
113435.213728 |
| i (deg) |
124.318754 |
| Ω (om, deg) |
203.324133 |
| ω (w, deg) |
83.399442 |
| M (ma, deg) |
359.999999 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.325 + 4.889\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.325 |
| n |
4.889 |
| gf |
0.999 |
| gb |
-0.767 |
| k |
0.993 |
| δ90 |
9.998 |
| 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) |
| 2026-03-26 00:00 |
00:25:53.35 |
-44:46:54.9 |
HIP 1992 |
20.51 |
| 2026-03-26 12:00 |
00:25:56.09 |
-44:46:46.6 |
HIP 1992 |
20.56 |
| 2026-03-27 00:00 |
00:25:58.84 |
-44:46:38.5 |
HIP 1992 |
20.62 |
| 2026-03-27 12:00 |
00:26:01.58 |
-44:46:30.6 |
HIP 1992 |
20.69 |
| 2026-03-28 00:00 |
00:26:04.33 |
-44:46:23.0 |
HIP 1992 |
20.78 |
| 2026-03-28 12:00 |
00:26:07.07 |
-44:46:15.5 |
HIP 1992 |
20.89 |
| 2026-03-29 00:00 |
00:26:09.82 |
-44:46:08.2 |
HIP 1992 |
21.01 |
| 2026-03-29 12:00 |
00:26:12.56 |
-44:46:01.1 |
HIP 1992 |
21.14 |
| 2026-03-30 00:00 |
00:26:15.31 |
-44:45:54.3 |
HIP 1992 |
21.29 |
| 2026-03-30 12:00 |
00:26:18.05 |
-44:45:47.6 |
HIP 1992 |
21.45 |
| 2026-03-31 00:00 |
00:26:20.79 |
-44:45:41.1 |
HIP 1992 |
21.62 |
| 2026-03-31 12:00 |
00:26:23.53 |
-44:45:34.9 |
HIP 1992 |
21.81 |
| 2026-04-01 00:00 |
00:26:26.27 |
-44:45:28.8 |
HIP 1992 |
22.01 |
| 2026-04-01 12:00 |
00:26:29.01 |
-44:45:22.9 |
HIP 1992 |
22.22 |
| 2026-04-02 00:00 |
00:26:31.74 |
-44:45:17.3 |
HIP 1992 |
22.44 |
| 2026-04-02 12:00 |
00:26:34.48 |
-44:45:11.8 |
HIP 1992 |
22.68 |
| 2026-04-03 00:00 |
00:26:37.21 |
-44:45:06.6 |
HIP 1992 |
22.92 |
| 2026-04-03 12:00 |
00:26:39.94 |
-44:45:01.6 |
HIP 1992 |
23.18 |
| 2026-04-04 00:00 |
00:26:42.66 |
-44:44:56.7 |
HIP 1992 |
23.44 |
| 2026-04-04 12:00 |
00:26:45.39 |
-44:44:52.1 |
HIP 1992 |
23.72 |
| 2026-04-05 00:00 |
00:26:48.11 |
-44:44:47.7 |
HIP 2266 |
23.59 |
| 2026-04-05 12:00 |
00:26:50.83 |
-44:44:43.5 |
HIP 2266 |
23.11 |
| 2026-04-06 00:00 |
00:26:53.54 |
-44:44:39.5 |
HIP 2266 |
22.64 |
| 2026-04-06 12:00 |
00:26:56.25 |
-44:44:35.7 |
HIP 2266 |
22.16 |
| 2026-04-07 00:00 |
00:26:58.96 |
-44:44:32.1 |
HIP 2266 |
21.69 |
| 2026-04-07 12:00 |
00:27:01.66 |
-44:44:28.7 |
HIP 2266 |
21.23 |
| 2026-04-08 00:00 |
00:27:04.36 |
-44:44:25.6 |
HIP 2266 |
20.77 |
| 2026-04-08 12:00 |
00:27:07.06 |
-44:44:22.6 |
HIP 2266 |
20.30 |
| 2026-04-09 00:00 |
00:27:09.75 |
-44:44:19.9 |
HIP 2266 |
19.85 |
| 2026-04-09 12:00 |
00:27:12.44 |
-44:44:17.4 |
HIP 2266 |
19.39 |
| 2026-04-10 00:00 |
00:27:15.12 |
-44:44:15.0 |
HIP 2266 |
18.94 |
| 2026-04-10 12:00 |
00:27:17.80 |
-44:44:12.9 |
HIP 2266 |
18.49 |
| 2026-04-11 00:00 |
00:27:20.47 |
-44:44:11.0 |
HIP 2266 |
18.05 |
| 2026-04-11 12:00 |
00:27:23.14 |
-44:44:09.3 |
HIP 2266 |
17.61 |
| 2026-04-12 00:00 |
00:27:25.80 |
-44:44:07.9 |
HIP 2266 |
17.18 |
| 2026-04-12 12:00 |
00:27:28.46 |
-44:44:06.6 |
HIP 2266 |
16.75 |
| 2026-04-13 00:00 |
00:27:31.11 |
-44:44:05.5 |
HIP 2266 |
16.32 |
| 2026-04-13 12:00 |
00:27:33.76 |
-44:44:04.7 |
HIP 2266 |
15.90 |
| 2026-04-14 00:00 |
00:27:36.39 |
-44:44:04.1 |
HIP 2266 |
15.49 |
| 2026-04-14 12:00 |
00:27:39.03 |
-44:44:03.7 |
HIP 2266 |
15.08 |
| 2026-04-15 00:00 |
00:27:41.65 |
-44:44:03.5 |
HIP 2266 |
14.68 |
| 2026-04-15 12:00 |
00:27:44.27 |
-44:44:03.5 |
HIP 2266 |
14.28 |
| 2026-04-16 00:00 |
00:27:46.88 |
-44:44:03.7 |
HIP 2266 |
13.89 |