| 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
$$
M_a = (3.371 + 5.121\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
3.371 |
| n |
5.121 |
| gf |
0.999 |
| gb |
-0.836 |
| k |
1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1991-01-13 |
1991-04-17 |
+6.2454 |
-3.858 |
| 1991-04-17 |
1991-12-31 |
-2.7201 |
+1.245 |
| 1992-01-01 |
1992-06-26 |
+4.1272 |
-1.528 |
| 1992-06-26 |
1993-10-08 |
-3.5694 |
+1.839 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
00:45:33.81 |
-52:53:50.4 |
HIP 3537 |
20.70 |
| 2026-09-20 12:00 |
00:45:30.81 |
-52:54:04.0 |
HIP 3537 |
20.39 |
| 2026-09-21 00:00 |
00:45:27.81 |
-52:54:17.4 |
HIP 3537 |
20.09 |
| 2026-09-21 12:00 |
00:45:24.79 |
-52:54:30.6 |
HIP 3537 |
19.81 |
| 2026-09-22 00:00 |
00:45:21.77 |
-52:54:43.5 |
HIP 3537 |
19.53 |
| 2026-09-22 12:00 |
00:45:18.74 |
-52:54:56.3 |
HIP 3537 |
19.27 |
| 2026-09-23 00:00 |
00:45:15.70 |
-52:55:08.8 |
HIP 3537 |
19.02 |
| 2026-09-23 12:00 |
00:45:12.66 |
-52:55:21.1 |
HIP 3537 |
18.79 |
| 2026-09-24 00:00 |
00:45:09.62 |
-52:55:33.2 |
HIP 3537 |
18.57 |
| 2026-09-24 12:00 |
00:45:06.56 |
-52:55:45.1 |
HIP 3537 |
18.37 |
| 2026-09-25 00:00 |
00:45:03.51 |
-52:55:56.7 |
HIP 3537 |
18.18 |
| 2026-09-25 12:00 |
00:45:00.44 |
-52:56:08.2 |
HIP 3537 |
18.00 |
| 2026-09-26 00:00 |
00:44:57.37 |
-52:56:19.4 |
HIP 3537 |
17.84 |
| 2026-09-26 12:00 |
00:44:54.30 |
-52:56:30.4 |
HIP 3537 |
17.70 |
| 2026-09-27 00:00 |
00:44:51.23 |
-52:56:41.1 |
HIP 3537 |
17.57 |
| 2026-09-27 12:00 |
00:44:48.14 |
-52:56:51.7 |
HIP 3537 |
17.47 |
| 2026-09-28 00:00 |
00:44:45.06 |
-52:57:02.0 |
HIP 3537 |
17.37 |
| 2026-09-28 12:00 |
00:44:41.97 |
-52:57:12.1 |
HIP 3537 |
17.30 |
| 2026-09-29 00:00 |
00:44:38.88 |
-52:57:21.9 |
HIP 3537 |
17.24 |
| 2026-09-29 12:00 |
00:44:35.78 |
-52:57:31.6 |
HIP 3537 |
17.20 |
| 2026-09-30 00:00 |
00:44:32.69 |
-52:57:41.0 |
HIP 3537 |
17.18 |
| 2026-09-30 12:00 |
00:44:29.59 |
-52:57:50.2 |
HIP 3537 |
17.18 |
| 2026-10-01 00:00 |
00:44:26.48 |
-52:57:59.1 |
HIP 3537 |
17.19 |
| 2026-10-01 12:00 |
00:44:23.38 |
-52:58:07.9 |
HIP 3537 |
17.23 |
| 2026-10-02 00:00 |
00:44:20.27 |
-52:58:16.4 |
HIP 3537 |
17.28 |
| 2026-10-02 12:00 |
00:44:17.16 |
-52:58:24.6 |
HIP 3537 |
17.34 |
| 2026-10-03 00:00 |
00:44:14.05 |
-52:58:32.7 |
HIP 3537 |
17.42 |
| 2026-10-03 12:00 |
00:44:10.94 |
-52:58:40.5 |
HIP 3537 |
17.52 |
| 2026-10-04 00:00 |
00:44:07.82 |
-52:58:48.0 |
HIP 3537 |
17.64 |
| 2026-10-04 12:00 |
00:44:04.71 |
-52:58:55.4 |
HIP 3537 |
17.77 |
| 2026-10-05 00:00 |
00:44:01.59 |
-52:59:02.5 |
HIP 3537 |
17.92 |
| 2026-10-05 12:00 |
00:43:58.48 |
-52:59:09.3 |
HIP 3537 |
18.08 |
| 2026-10-06 00:00 |
00:43:55.37 |
-52:59:16.0 |
HIP 3537 |
18.26 |
| 2026-10-06 12:00 |
00:43:52.25 |
-52:59:22.4 |
HIP 3537 |
18.45 |
| 2026-10-07 00:00 |
00:43:49.14 |
-52:59:28.5 |
HIP 3537 |
18.65 |
| 2026-10-07 12:00 |
00:43:46.02 |
-52:59:34.4 |
HIP 3537 |
18.87 |
| 2026-10-08 00:00 |
00:43:42.91 |
-52:59:40.1 |
HIP 3537 |
19.10 |
| 2026-10-08 12:00 |
00:43:39.80 |
-52:59:45.5 |
HIP 3292 |
19.22 |
| 2026-10-09 00:00 |
00:43:36.69 |
-52:59:50.7 |
HIP 3292 |
18.81 |
| 2026-10-09 12:00 |
00:43:33.59 |
-52:59:55.7 |
HIP 3292 |
18.40 |
| 2026-10-10 00:00 |
00:43:30.48 |
-53:00:00.4 |
HIP 3292 |
18.00 |
| 2026-10-10 12:00 |
00:43:27.38 |
-53:00:04.9 |
HIP 3292 |
17.60 |
| 2026-10-11 00:00 |
00:43:24.28 |
-53:00:09.1 |
HIP 3292 |
17.21 |