C/1988 L1 (Shoemaker-Holt-Rodriquez)
| Parameter |
Value |
| Designation |
C/1988 L1 (Shoemaker-Holt-Rodriquez) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1989-06-12T11:09:22.452480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:36Z |
| Obs used |
155 |
| NEO |
- |
| M1 |
9.200 |
| K1 |
4.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1988-11-06.0000000 |
| e |
1.00067716 |
| q (au) |
2.474297 |
| a (au) |
-3653.923503 |
| i (deg) |
97.688560 |
| Ω (om, deg) |
115.255065 |
| ω (w, deg) |
232.145920 |
| M (ma, deg) |
-0.000975 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.401 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.401 |
| n |
2.000 |
| gf |
0.995 |
| gb |
-0.685 |
| k |
0.999 |
| δ90 |
9.990 |
| 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) |
| 2026-02-03 00:00 |
07:55:27.97 |
+50:16:53.5 |
HIP 38769 |
16.96 |
| 2026-02-03 12:00 |
07:55:24.99 |
+50:16:55.1 |
HIP 38769 |
17.13 |
| 2026-02-04 00:00 |
07:55:22.00 |
+50:16:56.6 |
HIP 38769 |
17.32 |
| 2026-02-04 12:00 |
07:55:19.03 |
+50:16:57.9 |
HIP 38769 |
17.51 |
| 2026-02-05 00:00 |
07:55:16.07 |
+50:16:59.1 |
HIP 38769 |
17.72 |
| 2026-02-05 12:00 |
07:55:13.12 |
+50:17:00.2 |
HIP 38769 |
17.93 |
| 2026-02-06 00:00 |
07:55:10.17 |
+50:17:01.1 |
HIP 38769 |
18.16 |
| 2026-02-06 12:00 |
07:55:07.24 |
+50:17:01.9 |
HIP 38769 |
18.40 |
| 2026-02-07 00:00 |
07:55:04.31 |
+50:17:02.5 |
HIP 38769 |
18.65 |
| 2026-02-07 12:00 |
07:55:01.40 |
+50:17:03.0 |
HIP 38769 |
18.91 |
| 2026-02-08 00:00 |
07:54:58.49 |
+50:17:03.4 |
HIP 38769 |
19.17 |
| 2026-02-08 12:00 |
07:54:55.60 |
+50:17:03.6 |
HIP 38769 |
19.45 |
| 2026-02-09 00:00 |
07:54:52.72 |
+50:17:03.6 |
HIP 38769 |
19.73 |
| 2026-02-09 12:00 |
07:54:49.85 |
+50:17:03.6 |
HIP 38769 |
20.02 |
| 2026-02-10 00:00 |
07:54:46.99 |
+50:17:03.3 |
HIP 38769 |
20.32 |
| 2026-02-10 12:00 |
07:54:44.14 |
+50:17:03.0 |
HIP 38769 |
20.62 |
| 2026-02-11 00:00 |
07:54:41.30 |
+50:17:02.5 |
HIP 38769 |
20.93 |
| 2026-02-11 12:00 |
07:54:38.48 |
+50:17:01.8 |
HIP 38769 |
21.24 |
| 2026-02-12 00:00 |
07:54:35.66 |
+50:17:01.0 |
HIP 38443 |
21.00 |
| 2026-02-12 12:00 |
07:54:32.87 |
+50:17:00.1 |
HIP 38443 |
20.57 |
| 2026-02-13 00:00 |
07:54:30.08 |
+50:16:59.0 |
HIP 38443 |
20.15 |
| 2026-02-13 12:00 |
07:54:27.30 |
+50:16:57.8 |
HIP 38443 |
19.72 |
| 2026-02-14 00:00 |
07:54:24.54 |
+50:16:56.5 |
HIP 38443 |
19.30 |
| 2026-02-14 12:00 |
07:54:21.80 |
+50:16:55.0 |
HIP 38443 |
18.88 |
| 2026-02-15 00:00 |
07:54:19.06 |
+50:16:53.4 |
HIP 38443 |
18.46 |
| 2026-02-15 12:00 |
07:54:16.34 |
+50:16:51.6 |
HIP 38443 |
18.05 |
| 2026-02-16 00:00 |
07:54:13.64 |
+50:16:49.7 |
HIP 38443 |
17.63 |
| 2026-02-16 12:00 |
07:54:10.95 |
+50:16:47.6 |
HIP 38443 |
17.22 |
| 2026-02-17 00:00 |
07:54:08.27 |
+50:16:45.4 |
HIP 38443 |
16.82 |
| 2026-02-17 12:00 |
07:54:05.61 |
+50:16:43.1 |
HIP 38443 |
16.41 |
| 2026-02-18 00:00 |
07:54:02.96 |
+50:16:40.6 |
HIP 38443 |
16.01 |
| 2026-02-18 12:00 |
07:54:00.33 |
+50:16:38.0 |
HIP 38443 |
15.60 |
| 2026-02-19 00:00 |
07:53:57.72 |
+50:16:35.3 |
HIP 38443 |
15.21 |
| 2026-02-19 12:00 |
07:53:55.12 |
+50:16:32.4 |
HIP 38443 |
14.81 |
| 2026-02-20 00:00 |
07:53:52.53 |
+50:16:29.4 |
HIP 38443 |
14.41 |
| 2026-02-20 12:00 |
07:53:49.97 |
+50:16:26.3 |
HIP 38443 |
14.02 |
| 2026-02-21 00:00 |
07:53:47.41 |
+50:16:23.0 |
HIP 38443 |
13.63 |
| 2026-02-21 12:00 |
07:53:44.88 |
+50:16:19.6 |
HIP 38443 |
13.25 |
| 2026-02-22 00:00 |
07:53:42.36 |
+50:16:16.0 |
HIP 38443 |
12.87 |
| 2026-02-22 12:00 |
07:53:39.86 |
+50:16:12.4 |
HIP 38443 |
12.49 |
| 2026-02-23 00:00 |
07:53:37.38 |
+50:16:08.5 |
HIP 38443 |
12.11 |
| 2026-02-23 12:00 |
07:53:34.91 |
+50:16:04.6 |
HIP 38443 |
11.73 |
| 2026-02-24 00:00 |
07:53:32.46 |
+50:16:00.5 |
HIP 38443 |
11.36 |