| Parameter |
Value |
| Designation |
C/1991 T2 (Shoemaker-Levy) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1992-07-24T12:09:31.147200Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:41Z |
| Obs used |
212 |
| NEO |
- |
| M1 |
7.800 |
| K1 |
10.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1992-03-10.0000000 |
| e |
0.99986094 |
| q (au) |
0.836262 |
| a (au) |
6013.613507 |
| i (deg) |
113.496746 |
| Ω (om, deg) |
49.049164 |
| ω (w, deg) |
145.238453 |
| M (ma, deg) |
359.999711 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.493 + 3.615\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.493 |
| n |
3.615 |
| gf |
0.800 |
| gb |
-0.594 |
| k |
0.800 |
| δ90 |
2.404 |
| 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 |
| 1991-10-06 |
1992-04-05 |
+3.9104 |
-1.690 |
| 1992-04-05 |
1992-07-24 |
-0.6095 |
+0.014 |
| 1992-07-24 |
1992-08-19 |
+3.5301 |
+0.260 |
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 |
05:12:40.88 |
-20:39:39.9 |
HIP 24343 |
13.49 |
| 2026-09-20 12:00 |
05:12:40.52 |
-20:40:00.4 |
HIP 24343 |
13.76 |
| 2026-09-21 00:00 |
05:12:40.13 |
-20:40:20.9 |
HIP 24343 |
14.04 |
| 2026-09-21 12:00 |
05:12:39.73 |
-20:40:41.4 |
HIP 24343 |
14.32 |
| 2026-09-22 00:00 |
05:12:39.31 |
-20:41:01.9 |
HIP 24343 |
14.61 |
| 2026-09-22 12:00 |
05:12:38.87 |
-20:41:22.4 |
HIP 24343 |
14.91 |
| 2026-09-23 00:00 |
05:12:38.41 |
-20:41:42.8 |
HIP 24343 |
15.21 |
| 2026-09-23 12:00 |
05:12:37.93 |
-20:42:03.3 |
HIP 24343 |
15.52 |
| 2026-09-24 00:00 |
05:12:37.44 |
-20:42:23.7 |
HIP 24343 |
15.83 |
| 2026-09-24 12:00 |
05:12:36.93 |
-20:42:44.1 |
HIP 24343 |
16.15 |
| 2026-09-25 00:00 |
05:12:36.40 |
-20:43:04.5 |
HIP 24343 |
16.47 |
| 2026-09-25 12:00 |
05:12:35.85 |
-20:43:24.8 |
HIP 24343 |
16.80 |
| 2026-09-26 00:00 |
05:12:35.28 |
-20:43:45.2 |
HIP 24343 |
17.13 |
| 2026-09-26 12:00 |
05:12:34.69 |
-20:44:05.5 |
HIP 24343 |
17.47 |
| 2026-09-27 00:00 |
05:12:34.09 |
-20:44:25.8 |
HIP 24343 |
17.80 |
| 2026-09-27 12:00 |
05:12:33.47 |
-20:44:46.0 |
HIP 24343 |
18.15 |
| 2026-09-28 00:00 |
05:12:32.83 |
-20:45:06.3 |
HIP 24343 |
18.49 |
| 2026-09-28 12:00 |
05:12:32.17 |
-20:45:26.5 |
HIP 24343 |
18.84 |
| 2026-09-29 00:00 |
05:12:31.50 |
-20:45:46.7 |
HIP 24343 |
19.20 |
| 2026-09-29 12:00 |
05:12:30.81 |
-20:46:06.8 |
HIP 24343 |
19.55 |
| 2026-09-30 00:00 |
05:12:30.09 |
-20:46:26.9 |
HIP 24343 |
19.91 |
| 2026-09-30 12:00 |
05:12:29.36 |
-20:46:47.0 |
HIP 24343 |
20.27 |
| 2026-10-01 00:00 |
05:12:28.62 |
-20:47:07.0 |
HIP 24343 |
20.64 |
| 2026-10-01 12:00 |
05:12:27.85 |
-20:47:27.0 |
HIP 24343 |
21.00 |
| 2026-10-02 00:00 |
05:12:27.07 |
-20:47:47.0 |
HIP 24343 |
21.37 |
| 2026-10-02 12:00 |
05:12:26.27 |
-20:48:06.9 |
HIP 24343 |
21.75 |
| 2026-10-03 00:00 |
05:12:25.45 |
-20:48:26.7 |
HIP 24343 |
22.12 |
| 2026-10-03 12:00 |
05:12:24.62 |
-20:48:46.6 |
HIP 24343 |
22.50 |
| 2026-10-04 00:00 |
05:12:23.76 |
-20:49:06.3 |
HIP 24343 |
22.88 |
| 2026-10-04 12:00 |
05:12:22.89 |
-20:49:26.1 |
HIP 24343 |
23.26 |
| 2026-10-05 00:00 |
05:12:22.00 |
-20:49:45.8 |
HIP 24112 |
23.53 |
| 2026-10-05 12:00 |
05:12:21.10 |
-20:50:05.4 |
HIP 24112 |
23.39 |
| 2026-10-06 00:00 |
05:12:20.17 |
-20:50:25.0 |
HIP 24112 |
23.26 |
| 2026-10-06 12:00 |
05:12:19.23 |
-20:50:44.5 |
HIP 24112 |
23.12 |
| 2026-10-07 00:00 |
05:12:18.27 |
-20:51:03.9 |
HIP 24112 |
22.99 |
| 2026-10-07 12:00 |
05:12:17.30 |
-20:51:23.3 |
HIP 24112 |
22.86 |
| 2026-10-08 00:00 |
05:12:16.30 |
-20:51:42.7 |
HIP 24112 |
22.73 |
| 2026-10-08 12:00 |
05:12:15.29 |
-20:52:02.0 |
HIP 24112 |
22.61 |
| 2026-10-09 00:00 |
05:12:14.27 |
-20:52:21.2 |
HIP 24112 |
22.48 |
| 2026-10-09 12:00 |
05:12:13.22 |
-20:52:40.3 |
HIP 24112 |
22.36 |
| 2026-10-10 00:00 |
05:12:12.16 |
-20:52:59.4 |
HIP 24112 |
22.24 |
| 2026-10-10 12:00 |
05:12:11.08 |
-20:53:18.5 |
HIP 24112 |
22.13 |
| 2026-10-11 00:00 |
05:12:09.98 |
-20:53:37.4 |
HIP 24112 |
22.01 |