| Parameter |
Value |
| Designation |
C/1988 J1 (Shoemaker-Holt) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1988-02-14T05:17:56.938560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:36Z |
| Obs used |
84 |
| NEO |
- |
| M1 |
5.900 |
| K1 |
21.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1988-06-23.0000000 |
| e |
0.99780777 |
| q (au) |
1.174487 |
| a (au) |
535.749413 |
| i (deg) |
62.807050 |
| Ω (om, deg) |
288.765006 |
| ω (w, deg) |
326.515452 |
| M (ma, deg) |
0.010315 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.971 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.971 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.987 |
| 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) |
| 2026-03-26 00:00 |
04:48:58.27 |
+64:41:20.9 |
HIP 22191 |
17.13 |
| 2026-03-26 12:00 |
04:48:59.94 |
+64:41:03.3 |
HIP 22191 |
17.22 |
| 2026-03-27 00:00 |
04:49:01.64 |
+64:40:45.7 |
HIP 22191 |
17.32 |
| 2026-03-27 12:00 |
04:49:03.38 |
+64:40:28.2 |
HIP 22191 |
17.44 |
| 2026-03-28 00:00 |
04:49:05.16 |
+64:40:10.8 |
HIP 22191 |
17.56 |
| 2026-03-28 12:00 |
04:49:06.97 |
+64:39:53.5 |
HIP 22191 |
17.69 |
| 2026-03-29 00:00 |
04:49:08.81 |
+64:39:36.3 |
HIP 22191 |
17.84 |
| 2026-03-29 12:00 |
04:49:10.68 |
+64:39:19.2 |
HIP 22191 |
17.99 |
| 2026-03-30 00:00 |
04:49:12.59 |
+64:39:02.2 |
HIP 22191 |
18.15 |
| 2026-03-30 12:00 |
04:49:14.53 |
+64:38:45.2 |
HIP 22191 |
18.32 |
| 2026-03-31 00:00 |
04:49:16.51 |
+64:38:28.4 |
HIP 22191 |
18.50 |
| 2026-03-31 12:00 |
04:49:18.51 |
+64:38:11.6 |
HIP 22191 |
18.69 |
| 2026-04-01 00:00 |
04:49:20.55 |
+64:37:55.0 |
HIP 22191 |
18.88 |
| 2026-04-01 12:00 |
04:49:22.63 |
+64:37:38.4 |
HIP 22191 |
19.09 |
| 2026-04-02 00:00 |
04:49:24.73 |
+64:37:22.0 |
HIP 22191 |
19.30 |
| 2026-04-02 12:00 |
04:49:26.87 |
+64:37:05.6 |
HIP 22191 |
19.52 |
| 2026-04-03 00:00 |
04:49:29.04 |
+64:36:49.4 |
HIP 22191 |
19.75 |
| 2026-04-03 12:00 |
04:49:31.24 |
+64:36:33.2 |
HIP 22191 |
19.98 |
| 2026-04-04 00:00 |
04:49:33.47 |
+64:36:17.2 |
HIP 22191 |
20.23 |
| 2026-04-04 12:00 |
04:49:35.74 |
+64:36:01.3 |
HIP 22191 |
20.47 |
| 2026-04-05 00:00 |
04:49:38.04 |
+64:35:45.4 |
HIP 22191 |
20.73 |
| 2026-04-05 12:00 |
04:49:40.36 |
+64:35:29.7 |
HIP 22191 |
20.99 |
| 2026-04-06 00:00 |
04:49:42.72 |
+64:35:14.0 |
HIP 22191 |
21.26 |
| 2026-04-06 12:00 |
04:49:45.11 |
+64:34:58.5 |
HIP 22191 |
21.53 |
| 2026-04-07 00:00 |
04:49:47.53 |
+64:34:43.1 |
HIP 22191 |
21.81 |
| 2026-04-07 12:00 |
04:49:49.98 |
+64:34:27.8 |
HIP 22191 |
22.10 |
| 2026-04-08 00:00 |
04:49:52.46 |
+64:34:12.6 |
HIP 22191 |
22.39 |
| 2026-04-08 12:00 |
04:49:54.97 |
+64:33:57.5 |
HIP 22191 |
22.69 |
| 2026-04-09 00:00 |
04:49:57.51 |
+64:33:42.5 |
HIP 22191 |
22.99 |
| 2026-04-09 12:00 |
04:50:00.08 |
+64:33:27.7 |
HIP 22191 |
23.29 |
| 2026-04-10 00:00 |
04:50:02.68 |
+64:33:12.9 |
HIP 22191 |
23.61 |
| 2026-04-10 12:00 |
04:50:05.31 |
+64:32:58.3 |
HIP 22191 |
23.92 |
| 2026-04-11 00:00 |
04:50:07.97 |
+64:32:43.8 |
HIP 22191 |
24.24 |
| 2026-04-11 12:00 |
04:50:10.66 |
+64:32:29.4 |
HIP 22191 |
24.57 |
| 2026-04-12 00:00 |
04:50:13.37 |
+64:32:15.1 |
HIP 22191 |
24.89 |
| 2026-04-12 12:00 |
04:50:16.12 |
+64:32:00.9 |
HIP 22191 |
25.23 |
| 2026-04-13 00:00 |
04:50:18.89 |
+64:31:46.9 |
HIP 22191 |
25.56 |
| 2026-04-13 12:00 |
04:50:21.69 |
+64:31:32.9 |
HIP 22191 |
25.91 |
| 2026-04-14 00:00 |
04:50:24.52 |
+64:31:19.1 |
HIP 22191 |
26.25 |
| 2026-04-14 12:00 |
04:50:27.38 |
+64:31:05.4 |
HIP 22191 |
26.60 |
| 2026-04-15 00:00 |
04:50:30.26 |
+64:30:51.8 |
HIP 22191 |
26.95 |
| 2026-04-15 12:00 |
04:50:33.17 |
+64:30:38.4 |
HIP 22191 |
27.30 |
| 2026-04-16 00:00 |
04:50:36.11 |
+64:30:25.1 |
HIP 22191 |
27.66 |