| 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 |
-0.502 |
| 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) |
| 2026-03-26 00:00 |
07:18:28.66 |
-61:21:46.8 |
HIP 35312 |
6.93 |
| 2026-03-26 12:00 |
07:18:27.67 |
-61:21:19.9 |
HIP 35312 |
7.07 |
| 2026-03-27 00:00 |
07:18:26.72 |
-61:20:52.9 |
HIP 35312 |
7.25 |
| 2026-03-27 12:00 |
07:18:25.80 |
-61:20:25.9 |
HIP 35312 |
7.45 |
| 2026-03-28 00:00 |
07:18:24.92 |
-61:19:58.8 |
HIP 35312 |
7.68 |
| 2026-03-28 12:00 |
07:18:24.07 |
-61:19:31.7 |
HIP 35312 |
7.94 |
| 2026-03-29 00:00 |
07:18:23.25 |
-61:19:04.5 |
HIP 35312 |
8.21 |
| 2026-03-29 12:00 |
07:18:22.46 |
-61:18:37.4 |
HIP 35312 |
8.50 |
| 2026-03-30 00:00 |
07:18:21.70 |
-61:18:10.1 |
HIP 35312 |
8.82 |
| 2026-03-30 12:00 |
07:18:20.98 |
-61:17:42.9 |
HIP 35312 |
9.14 |
| 2026-03-31 00:00 |
07:18:20.29 |
-61:17:15.6 |
HIP 35312 |
9.48 |
| 2026-03-31 12:00 |
07:18:19.64 |
-61:16:48.3 |
HIP 35312 |
9.84 |
| 2026-04-01 00:00 |
07:18:19.01 |
-61:16:21.0 |
HIP 35312 |
10.20 |
| 2026-04-01 12:00 |
07:18:18.42 |
-61:15:53.6 |
HIP 35312 |
10.57 |
| 2026-04-02 00:00 |
07:18:17.86 |
-61:15:26.2 |
HIP 35312 |
10.95 |
| 2026-04-02 12:00 |
07:18:17.34 |
-61:14:58.8 |
HIP 35497 |
11.00 |
| 2026-04-03 00:00 |
07:18:16.85 |
-61:14:31.4 |
HIP 35497 |
10.80 |
| 2026-04-03 12:00 |
07:18:16.39 |
-61:14:04.0 |
HIP 35497 |
10.61 |
| 2026-04-04 00:00 |
07:18:15.96 |
-61:13:36.5 |
HIP 35497 |
10.43 |
| 2026-04-04 12:00 |
07:18:15.56 |
-61:13:09.1 |
HIP 35497 |
10.26 |
| 2026-04-05 00:00 |
07:18:15.20 |
-61:12:41.6 |
HIP 35497 |
10.12 |
| 2026-04-05 12:00 |
07:18:14.87 |
-61:12:14.1 |
HIP 35497 |
9.98 |
| 2026-04-06 00:00 |
07:18:14.58 |
-61:11:46.6 |
HIP 35497 |
9.86 |
| 2026-04-06 12:00 |
07:18:14.31 |
-61:11:19.2 |
HIP 35497 |
9.76 |
| 2026-04-07 00:00 |
07:18:14.08 |
-61:10:51.7 |
HIP 35497 |
9.68 |
| 2026-04-07 12:00 |
07:18:13.88 |
-61:10:24.2 |
HIP 35497 |
9.61 |
| 2026-04-08 00:00 |
07:18:13.72 |
-61:09:56.7 |
HIP 35497 |
9.56 |
| 2026-04-08 12:00 |
07:18:13.58 |
-61:09:29.2 |
HIP 35497 |
9.53 |
| 2026-04-09 00:00 |
07:18:13.48 |
-61:09:01.7 |
HIP 35497 |
9.52 |
| 2026-04-09 12:00 |
07:18:13.42 |
-61:08:34.3 |
HIP 35497 |
9.52 |
| 2026-04-10 00:00 |
07:18:13.38 |
-61:08:06.8 |
HIP 35497 |
9.54 |
| 2026-04-10 12:00 |
07:18:13.38 |
-61:07:39.3 |
HIP 35497 |
9.58 |
| 2026-04-11 00:00 |
07:18:13.41 |
-61:07:11.9 |
HIP 35497 |
9.64 |
| 2026-04-11 12:00 |
07:18:13.47 |
-61:06:44.5 |
HIP 35497 |
9.72 |
| 2026-04-12 00:00 |
07:18:13.56 |
-61:06:17.1 |
HIP 35497 |
9.81 |
| 2026-04-12 12:00 |
07:18:13.69 |
-61:05:49.7 |
HIP 35497 |
9.92 |
| 2026-04-13 00:00 |
07:18:13.85 |
-61:05:22.3 |
HIP 35497 |
10.04 |
| 2026-04-13 12:00 |
07:18:14.04 |
-61:04:55.0 |
HIP 35497 |
10.18 |
| 2026-04-14 00:00 |
07:18:14.26 |
-61:04:27.7 |
HIP 35497 |
10.34 |
| 2026-04-14 12:00 |
07:18:14.52 |
-61:04:00.4 |
HIP 35497 |
10.50 |
| 2026-04-15 00:00 |
07:18:14.81 |
-61:03:33.2 |
HIP 35497 |
10.69 |
| 2026-04-15 12:00 |
07:18:15.13 |
-61:03:05.9 |
HIP 35497 |
10.88 |
| 2026-04-16 00:00 |
07:18:15.48 |
-61:02:38.7 |
HIP 35497 |
11.08 |