| Parameter |
Value |
| Designation |
C/1991 B1 (Shoemaker-Levy) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1991-12-31T04:34:48.403200Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:40Z |
| Obs used |
429 |
| NEO |
- |
| M1 |
6.500 |
| K1 |
9.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1992-05-14.0000000 |
| e |
0.99357570 |
| q (au) |
2.265069 |
| a (au) |
352.578443 |
| i (deg) |
77.287941 |
| Ω (om, deg) |
145.130159 |
| ω (w, deg) |
74.368785 |
| M (ma, deg) |
0.020070 |
Magnitude
Scatter + Global Linear
$$
M_a = (3.416 + 5.065\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
3.416 |
| n |
5.065 |
| gf |
1.000 |
| gb |
-0.500 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1991-01-13 |
1991-04-17 |
+5.4067 |
-3.381 |
| 1991-04-17 |
1991-12-31 |
-2.6378 |
+1.210 |
| 1992-01-01 |
1992-06-26 |
+4.2282 |
-1.567 |
| 1992-06-26 |
1993-10-08 |
-3.6144 |
+1.867 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
00:42:33.80 |
-51:14:56.9 |
HIP 3213 |
17.68 |
| 2026-03-26 12:00 |
00:42:36.96 |
-51:14:47.5 |
HIP 3213 |
18.19 |
| 2026-03-27 00:00 |
00:42:40.12 |
-51:14:38.3 |
HIP 3422 |
18.28 |
| 2026-03-27 12:00 |
00:42:43.29 |
-51:14:29.3 |
HIP 3422 |
17.91 |
| 2026-03-28 00:00 |
00:42:46.46 |
-51:14:20.5 |
HIP 3422 |
17.55 |
| 2026-03-28 12:00 |
00:42:49.63 |
-51:14:12.0 |
HIP 3422 |
17.21 |
| 2026-03-29 00:00 |
00:42:52.81 |
-51:14:03.6 |
HIP 3422 |
16.88 |
| 2026-03-29 12:00 |
00:42:55.98 |
-51:13:55.5 |
HIP 3422 |
16.56 |
| 2026-03-30 00:00 |
00:42:59.16 |
-51:13:47.5 |
HIP 3422 |
16.25 |
| 2026-03-30 12:00 |
00:43:02.33 |
-51:13:39.8 |
HIP 3422 |
15.96 |
| 2026-03-31 00:00 |
00:43:05.51 |
-51:13:32.3 |
HIP 3422 |
15.69 |
| 2026-03-31 12:00 |
00:43:08.69 |
-51:13:25.1 |
HIP 3422 |
15.43 |
| 2026-04-01 00:00 |
00:43:11.87 |
-51:13:18.0 |
HIP 3422 |
15.18 |
| 2026-04-01 12:00 |
00:43:15.05 |
-51:13:11.2 |
HIP 3422 |
14.95 |
| 2026-04-02 00:00 |
00:43:18.22 |
-51:13:04.5 |
HIP 3422 |
14.74 |
| 2026-04-02 12:00 |
00:43:21.40 |
-51:12:58.1 |
HIP 3422 |
14.55 |
| 2026-04-03 00:00 |
00:43:24.58 |
-51:12:51.9 |
HIP 3422 |
14.38 |
| 2026-04-03 12:00 |
00:43:27.76 |
-51:12:45.9 |
HIP 3422 |
14.23 |
| 2026-04-04 00:00 |
00:43:30.93 |
-51:12:40.2 |
HIP 3422 |
14.10 |
| 2026-04-04 12:00 |
00:43:34.11 |
-51:12:34.6 |
HIP 3422 |
13.99 |
| 2026-04-05 00:00 |
00:43:37.29 |
-51:12:29.3 |
HIP 3422 |
13.90 |
| 2026-04-05 12:00 |
00:43:40.46 |
-51:12:24.2 |
HIP 3422 |
13.83 |
| 2026-04-06 00:00 |
00:43:43.63 |
-51:12:19.3 |
HIP 3422 |
13.78 |
| 2026-04-06 12:00 |
00:43:46.80 |
-51:12:14.7 |
HIP 3422 |
13.76 |
| 2026-04-07 00:00 |
00:43:49.97 |
-51:12:10.2 |
HIP 3422 |
13.76 |
| 2026-04-07 12:00 |
00:43:53.13 |
-51:12:06.0 |
HIP 3422 |
13.77 |
| 2026-04-08 00:00 |
00:43:56.30 |
-51:12:02.0 |
HIP 3422 |
13.82 |
| 2026-04-08 12:00 |
00:43:59.46 |
-51:11:58.2 |
HIP 3422 |
13.88 |
| 2026-04-09 00:00 |
00:44:02.62 |
-51:11:54.6 |
HIP 3422 |
13.96 |
| 2026-04-09 12:00 |
00:44:05.77 |
-51:11:51.3 |
HIP 3422 |
14.07 |
| 2026-04-10 00:00 |
00:44:08.92 |
-51:11:48.2 |
HIP 3422 |
14.19 |
| 2026-04-10 12:00 |
00:44:12.07 |
-51:11:45.3 |
HIP 3422 |
14.34 |
| 2026-04-11 00:00 |
00:44:15.22 |
-51:11:42.6 |
HIP 3422 |
14.50 |
| 2026-04-11 12:00 |
00:44:18.36 |
-51:11:40.2 |
HIP 3422 |
14.68 |
| 2026-04-12 00:00 |
00:44:21.50 |
-51:11:38.0 |
HIP 3422 |
14.88 |
| 2026-04-12 12:00 |
00:44:24.63 |
-51:11:36.0 |
HIP 3422 |
15.09 |
| 2026-04-13 00:00 |
00:44:27.76 |
-51:11:34.2 |
HIP 3422 |
15.32 |
| 2026-04-13 12:00 |
00:44:30.89 |
-51:11:32.6 |
HIP 3422 |
15.57 |
| 2026-04-14 00:00 |
00:44:34.01 |
-51:11:31.3 |
HIP 3422 |
15.83 |
| 2026-04-14 12:00 |
00:44:37.12 |
-51:11:30.2 |
HIP 3422 |
16.10 |
| 2026-04-15 00:00 |
00:44:40.23 |
-51:11:29.3 |
HIP 3422 |
16.38 |
| 2026-04-15 12:00 |
00:44:43.33 |
-51:11:28.7 |
HIP 3422 |
16.68 |
| 2026-04-16 00:00 |
00:44:46.43 |
-51:11:28.3 |
HIP 3422 |
16.99 |