C/1991 L3 (Levy)
| Parameter |
Value |
| Designation |
C/1991 L3 (Levy) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1991-07-08T04:44:18.885120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:41Z |
| Obs used |
136 |
| NEO |
Yes |
| M1 |
8.900 |
| K1 |
14.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1991-12-29.0000000 |
| e |
0.92885840 |
| q (au) |
0.982684 |
| a (au) |
13.813077 |
| i (deg) |
19.190108 |
| Ω (om, deg) |
329.431597 |
| ω (w, deg) |
41.478818 |
| M (ma, deg) |
3.336757 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.810 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.810 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.533 |
| k |
0.800 |
| 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) |
| 2026-02-03 00:00 |
12:43:27.51 |
-20:20:27.5 |
HIP 62264 |
31.64 |
| 2026-02-03 12:00 |
12:43:25.19 |
-20:20:32.4 |
HIP 61930 |
31.45 |
| 2026-02-04 00:00 |
12:43:22.83 |
-20:20:37.0 |
HIP 61930 |
30.94 |
| 2026-02-04 12:00 |
12:43:20.43 |
-20:20:41.4 |
HIP 61930 |
30.43 |
| 2026-02-05 00:00 |
12:43:18.00 |
-20:20:45.4 |
HIP 61930 |
29.91 |
| 2026-02-05 12:00 |
12:43:15.53 |
-20:20:49.1 |
HIP 61930 |
29.39 |
| 2026-02-06 00:00 |
12:43:13.02 |
-20:20:52.5 |
HIP 61930 |
28.87 |
| 2026-02-06 12:00 |
12:43:10.47 |
-20:20:55.7 |
HIP 61930 |
28.35 |
| 2026-02-07 00:00 |
12:43:07.89 |
-20:20:58.5 |
HIP 61930 |
27.83 |
| 2026-02-07 12:00 |
12:43:05.28 |
-20:21:01.0 |
HIP 61930 |
27.30 |
| 2026-02-08 00:00 |
12:43:02.62 |
-20:21:03.2 |
HIP 61930 |
26.78 |
| 2026-02-08 12:00 |
12:42:59.93 |
-20:21:05.1 |
HIP 61930 |
26.26 |
| 2026-02-09 00:00 |
12:42:57.21 |
-20:21:06.8 |
HIP 61930 |
25.74 |
| 2026-02-09 12:00 |
12:42:54.45 |
-20:21:08.1 |
HIP 61930 |
25.22 |
| 2026-02-10 00:00 |
12:42:51.65 |
-20:21:09.1 |
HIP 61930 |
24.70 |
| 2026-02-10 12:00 |
12:42:48.82 |
-20:21:09.8 |
HIP 61930 |
24.19 |
| 2026-02-11 00:00 |
12:42:45.96 |
-20:21:10.2 |
HIP 61930 |
23.68 |
| 2026-02-11 12:00 |
12:42:43.06 |
-20:21:10.2 |
HIP 61930 |
23.18 |
| 2026-02-12 00:00 |
12:42:40.12 |
-20:21:10.0 |
HIP 61930 |
22.69 |
| 2026-02-12 12:00 |
12:42:37.15 |
-20:21:09.5 |
HIP 61930 |
22.20 |
| 2026-02-13 00:00 |
12:42:34.15 |
-20:21:08.7 |
HIP 61930 |
21.72 |
| 2026-02-13 12:00 |
12:42:31.12 |
-20:21:07.5 |
HIP 61930 |
21.26 |
| 2026-02-14 00:00 |
12:42:28.05 |
-20:21:06.1 |
HIP 61930 |
20.81 |
| 2026-02-14 12:00 |
12:42:24.94 |
-20:21:04.3 |
HIP 61930 |
20.37 |
| 2026-02-15 00:00 |
12:42:21.81 |
-20:21:02.3 |
HIP 61930 |
19.95 |
| 2026-02-15 12:00 |
12:42:18.64 |
-20:20:59.9 |
HIP 61930 |
19.54 |
| 2026-02-16 00:00 |
12:42:15.44 |
-20:20:57.2 |
HIP 61930 |
19.16 |
| 2026-02-16 12:00 |
12:42:12.20 |
-20:20:54.2 |
HIP 61930 |
18.80 |
| 2026-02-17 00:00 |
12:42:08.94 |
-20:20:50.9 |
HIP 61930 |
18.46 |
| 2026-02-17 12:00 |
12:42:05.64 |
-20:20:47.4 |
HIP 61930 |
18.16 |
| 2026-02-18 00:00 |
12:42:02.31 |
-20:20:43.5 |
HIP 61930 |
17.88 |
| 2026-02-18 12:00 |
12:41:58.95 |
-20:20:39.2 |
HIP 61930 |
17.63 |
| 2026-02-19 00:00 |
12:41:55.56 |
-20:20:34.7 |
HIP 61930 |
17.42 |
| 2026-02-19 12:00 |
12:41:52.14 |
-20:20:29.9 |
HIP 61930 |
17.25 |
| 2026-02-20 00:00 |
12:41:48.69 |
-20:20:24.8 |
HIP 61930 |
17.12 |
| 2026-02-20 12:00 |
12:41:45.21 |
-20:20:19.4 |
HIP 61930 |
17.02 |
| 2026-02-21 00:00 |
12:41:41.71 |
-20:20:13.6 |
HIP 61930 |
16.97 |
| 2026-02-21 12:00 |
12:41:38.17 |
-20:20:07.6 |
HIP 61930 |
16.97 |
| 2026-02-22 00:00 |
12:41:34.60 |
-20:20:01.3 |
HIP 61930 |
17.01 |
| 2026-02-22 12:00 |
12:41:31.00 |
-20:19:54.6 |
HIP 61930 |
17.10 |
| 2026-02-23 00:00 |
12:41:27.38 |
-20:19:47.7 |
HIP 61930 |
17.23 |
| 2026-02-23 12:00 |
12:41:23.73 |
-20:19:40.5 |
HIP 61930 |
17.41 |
| 2026-02-24 00:00 |
12:41:20.05 |
-20:19:32.9 |
HIP 61930 |
17.64 |