| 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) |
| 2026-05-12 00:00 |
04:53:40.02 |
+64:21:57.4 |
HIP 22961 |
18.08 |
| 2026-05-12 12:00 |
04:53:44.03 |
+64:21:51.4 |
HIP 22961 |
17.66 |
| 2026-05-13 00:00 |
04:53:48.06 |
+64:21:45.6 |
HIP 22961 |
17.24 |
| 2026-05-13 12:00 |
04:53:52.11 |
+64:21:39.9 |
HIP 22961 |
16.82 |
| 2026-05-14 00:00 |
04:53:56.16 |
+64:21:34.3 |
HIP 22961 |
16.40 |
| 2026-05-14 12:00 |
04:54:00.23 |
+64:21:29.0 |
HIP 22961 |
15.98 |
| 2026-05-15 00:00 |
04:54:04.32 |
+64:21:23.7 |
HIP 22961 |
15.57 |
| 2026-05-15 12:00 |
04:54:08.41 |
+64:21:18.6 |
HIP 22961 |
15.15 |
| 2026-05-16 00:00 |
04:54:12.52 |
+64:21:13.7 |
HIP 22961 |
14.73 |
| 2026-05-16 12:00 |
04:54:16.64 |
+64:21:08.9 |
HIP 22961 |
14.31 |
| 2026-05-17 00:00 |
04:54:20.77 |
+64:21:04.3 |
HIP 22961 |
13.89 |
| 2026-05-17 12:00 |
04:54:24.91 |
+64:20:59.8 |
HIP 22961 |
13.47 |
| 2026-05-18 00:00 |
04:54:29.06 |
+64:20:55.4 |
HIP 22961 |
13.05 |
| 2026-05-18 12:00 |
04:54:33.22 |
+64:20:51.2 |
HIP 22961 |
12.64 |
| 2026-05-19 00:00 |
04:54:37.39 |
+64:20:47.2 |
HIP 22961 |
12.22 |
| 2026-05-19 12:00 |
04:54:41.58 |
+64:20:43.3 |
HIP 22961 |
11.81 |
| 2026-05-20 00:00 |
04:54:45.77 |
+64:20:39.6 |
HIP 22961 |
11.39 |
| 2026-05-20 12:00 |
04:54:49.97 |
+64:20:36.0 |
HIP 22961 |
10.98 |
| 2026-05-21 00:00 |
04:54:54.18 |
+64:20:32.6 |
HIP 22961 |
10.57 |
| 2026-05-21 12:00 |
04:54:58.40 |
+64:20:29.3 |
HIP 22961 |
10.16 |
| 2026-05-22 00:00 |
04:55:02.63 |
+64:20:26.2 |
HIP 22961 |
9.76 |
| 2026-05-22 12:00 |
04:55:06.86 |
+64:20:23.2 |
HIP 22961 |
9.36 |
| 2026-05-23 00:00 |
04:55:11.10 |
+64:20:20.4 |
HIP 22961 |
8.96 |
| 2026-05-23 12:00 |
04:55:15.36 |
+64:20:17.8 |
HIP 22961 |
8.57 |
| 2026-05-24 00:00 |
04:55:19.61 |
+64:20:15.2 |
HIP 22961 |
8.18 |
| 2026-05-24 12:00 |
04:55:23.88 |
+64:20:12.9 |
HIP 22961 |
7.80 |
| 2026-05-25 00:00 |
04:55:28.15 |
+64:20:10.7 |
HIP 22961 |
7.42 |
| 2026-05-25 12:00 |
04:55:32.43 |
+64:20:08.6 |
HIP 22961 |
7.05 |
| 2026-05-26 00:00 |
04:55:36.72 |
+64:20:06.7 |
HIP 22961 |
6.70 |
| 2026-05-26 12:00 |
04:55:41.01 |
+64:20:05.0 |
HIP 22961 |
6.35 |
| 2026-05-27 00:00 |
04:55:45.30 |
+64:20:03.4 |
HIP 22961 |
6.02 |
| 2026-05-27 12:00 |
04:55:49.61 |
+64:20:01.9 |
HIP 22961 |
5.71 |
| 2026-05-28 00:00 |
04:55:53.91 |
+64:20:00.6 |
HIP 22961 |
5.42 |
| 2026-05-28 12:00 |
04:55:58.23 |
+64:19:59.4 |
HIP 22961 |
5.15 |
| 2026-05-29 00:00 |
04:56:02.54 |
+64:19:58.4 |
HIP 22961 |
4.90 |
| 2026-05-29 12:00 |
04:56:06.86 |
+64:19:57.6 |
HIP 22961 |
4.69 |
| 2026-05-30 00:00 |
04:56:11.19 |
+64:19:56.9 |
HIP 22961 |
4.52 |
| 2026-05-30 12:00 |
04:56:15.52 |
+64:19:56.4 |
HIP 22961 |
4.38 |
| 2026-05-31 00:00 |
04:56:19.85 |
+64:19:56.0 |
HIP 22961 |
4.29 |
| 2026-05-31 12:00 |
04:56:24.19 |
+64:19:55.7 |
HIP 22961 |
4.25 |
| 2026-06-01 00:00 |
04:56:28.53 |
+64:19:55.6 |
HIP 22961 |
4.25 |
| 2026-06-01 12:00 |
04:56:32.87 |
+64:19:55.7 |
HIP 22961 |
4.31 |
| 2026-06-02 00:00 |
04:56:37.22 |
+64:19:55.9 |
HIP 22961 |
4.41 |