| Parameter |
Value |
| Designation |
C/1987 A1 (Levy) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1986-12-17T12:41:46.420800Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:33Z |
| Obs used |
62 |
| NEO |
- |
| M1 |
10.800 |
| K1 |
21.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1987-02-19.0000000 |
| e |
1.00039441 |
| q (au) |
0.921480 |
| a (au) |
-2336.349359 |
| i (deg) |
96.582920 |
| Ω (om, deg) |
17.116643 |
| ω (w, deg) |
95.245094 |
| M (ma, deg) |
0.000554 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.544 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.544 |
| n |
6.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
07:20:49.08 |
-60:27:27.9 |
HIP 35650 |
12.95 |
| 2026-06-01 12:00 |
07:20:51.84 |
-60:27:11.5 |
HIP 35650 |
12.59 |
| 2026-06-02 00:00 |
07:20:54.63 |
-60:26:55.2 |
HIP 35650 |
12.23 |
| 2026-06-02 12:00 |
07:20:57.43 |
-60:26:39.2 |
HIP 35650 |
11.88 |
| 2026-06-03 00:00 |
07:21:00.25 |
-60:26:23.3 |
HIP 35650 |
11.53 |
| 2026-06-03 12:00 |
07:21:03.09 |
-60:26:07.6 |
HIP 35650 |
11.20 |
| 2026-06-04 00:00 |
07:21:05.94 |
-60:25:52.0 |
HIP 35650 |
10.87 |
| 2026-06-04 12:00 |
07:21:08.81 |
-60:25:36.7 |
HIP 35650 |
10.56 |
| 2026-06-05 00:00 |
07:21:11.70 |
-60:25:21.5 |
HIP 35650 |
10.26 |
| 2026-06-05 12:00 |
07:21:14.60 |
-60:25:06.6 |
HIP 35650 |
9.97 |
| 2026-06-06 00:00 |
07:21:17.53 |
-60:24:51.8 |
HIP 35650 |
9.69 |
| 2026-06-06 12:00 |
07:21:20.46 |
-60:24:37.2 |
HIP 35650 |
9.43 |
| 2026-06-07 00:00 |
07:21:23.42 |
-60:24:22.8 |
HIP 35650 |
9.19 |
| 2026-06-07 12:00 |
07:21:26.38 |
-60:24:08.6 |
HIP 35650 |
8.96 |
| 2026-06-08 00:00 |
07:21:29.37 |
-60:23:54.5 |
HIP 35650 |
8.76 |
| 2026-06-08 12:00 |
07:21:32.37 |
-60:23:40.7 |
HIP 35650 |
8.57 |
| 2026-06-09 00:00 |
07:21:35.38 |
-60:23:27.1 |
HIP 35650 |
8.41 |
| 2026-06-09 12:00 |
07:21:38.41 |
-60:23:13.6 |
HIP 35650 |
8.27 |
| 2026-06-10 00:00 |
07:21:41.46 |
-60:23:00.4 |
HIP 35650 |
8.15 |
| 2026-06-10 12:00 |
07:21:44.52 |
-60:22:47.3 |
HIP 35650 |
8.07 |
| 2026-06-11 00:00 |
07:21:47.59 |
-60:22:34.5 |
HIP 35650 |
8.00 |
| 2026-06-11 12:00 |
07:21:50.68 |
-60:22:21.8 |
HIP 35650 |
7.97 |
| 2026-06-12 00:00 |
07:21:53.78 |
-60:22:09.3 |
HIP 35650 |
7.96 |
| 2026-06-12 12:00 |
07:21:56.90 |
-60:21:57.1 |
HIP 35650 |
7.98 |
| 2026-06-13 00:00 |
07:22:00.03 |
-60:21:45.0 |
HIP 35650 |
8.03 |
| 2026-06-13 12:00 |
07:22:03.17 |
-60:21:33.2 |
HIP 35650 |
8.10 |
| 2026-06-14 00:00 |
07:22:06.33 |
-60:21:21.5 |
HIP 35650 |
8.21 |
| 2026-06-14 12:00 |
07:22:09.49 |
-60:21:10.0 |
HIP 35650 |
8.33 |
| 2026-06-15 00:00 |
07:22:12.68 |
-60:20:58.8 |
HIP 35650 |
8.48 |
| 2026-06-15 12:00 |
07:22:15.87 |
-60:20:47.8 |
HIP 35650 |
8.66 |
| 2026-06-16 00:00 |
07:22:19.07 |
-60:20:36.9 |
HIP 35650 |
8.85 |
| 2026-06-16 12:00 |
07:22:22.29 |
-60:20:26.3 |
HIP 35650 |
9.06 |
| 2026-06-17 00:00 |
07:22:25.52 |
-60:20:15.9 |
HIP 35650 |
9.30 |
| 2026-06-17 12:00 |
07:22:28.76 |
-60:20:05.6 |
HIP 35650 |
9.55 |
| 2026-06-18 00:00 |
07:22:32.01 |
-60:19:55.6 |
HIP 35650 |
9.82 |
| 2026-06-18 12:00 |
07:22:35.27 |
-60:19:45.8 |
HIP 35650 |
10.10 |
| 2026-06-19 00:00 |
07:22:38.55 |
-60:19:36.2 |
HIP 35650 |
10.39 |
| 2026-06-19 12:00 |
07:22:41.83 |
-60:19:26.9 |
HIP 35650 |
10.70 |
| 2026-06-20 00:00 |
07:22:45.12 |
-60:19:17.7 |
HIP 35650 |
11.02 |
| 2026-06-20 12:00 |
07:22:48.43 |
-60:19:08.7 |
HIP 35650 |
11.34 |
| 2026-06-21 00:00 |
07:22:51.74 |
-60:19:00.0 |
HIP 35650 |
11.68 |
| 2026-06-21 12:00 |
07:22:55.06 |
-60:18:51.5 |
HIP 35650 |
12.03 |
| 2026-06-22 00:00 |
07:22:58.39 |
-60:18:43.1 |
HIP 35650 |
12.38 |