| Parameter |
Value |
| Designation |
C/1987 T1 (Levy) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1987-09-09T04:04:28.231680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:33Z |
| Obs used |
18 |
| NEO |
- |
| M1 |
9.200 |
| K1 |
31.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1987-10-24.0000000 |
| e |
0.99999043 |
| q (au) |
0.515261 |
| a (au) |
53860.674252 |
| i (deg) |
62.532659 |
| Ω (om, deg) |
143.730188 |
| ω (w, deg) |
13.191234 |
| M (ma, deg) |
0.000004 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.708 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.708 |
| n |
6.000 |
| gf |
0.994 |
| gb |
-1.000 |
| k |
1.000 |
| δ90 |
9.999 |
| 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) |
| 2026-05-12 00:00 |
21:56:21.51 |
-15:18:09.9 |
HIP 108176 |
19.77 |
| 2026-05-12 12:00 |
21:56:21.73 |
-15:18:10.5 |
HIP 108176 |
19.82 |
| 2026-05-13 00:00 |
21:56:21.94 |
-15:18:11.2 |
HIP 108176 |
19.87 |
| 2026-05-13 12:00 |
21:56:22.12 |
-15:18:11.9 |
HIP 108176 |
19.92 |
| 2026-05-14 00:00 |
21:56:22.30 |
-15:18:12.8 |
HIP 108176 |
19.96 |
| 2026-05-14 12:00 |
21:56:22.46 |
-15:18:13.7 |
HIP 108176 |
20.00 |
| 2026-05-15 00:00 |
21:56:22.60 |
-15:18:14.7 |
HIP 108176 |
20.04 |
| 2026-05-15 12:00 |
21:56:22.73 |
-15:18:15.7 |
HIP 108176 |
20.07 |
| 2026-05-16 00:00 |
21:56:22.84 |
-15:18:16.9 |
HIP 108176 |
20.10 |
| 2026-05-16 12:00 |
21:56:22.93 |
-15:18:18.1 |
HIP 108176 |
20.13 |
| 2026-05-17 00:00 |
21:56:23.02 |
-15:18:19.4 |
HIP 108176 |
20.15 |
| 2026-05-17 12:00 |
21:56:23.08 |
-15:18:20.8 |
HIP 108176 |
20.17 |
| 2026-05-18 00:00 |
21:56:23.13 |
-15:18:22.3 |
HIP 108176 |
20.19 |
| 2026-05-18 12:00 |
21:56:23.17 |
-15:18:23.8 |
HIP 108176 |
20.20 |
| 2026-05-19 00:00 |
21:56:23.19 |
-15:18:25.5 |
HIP 108176 |
20.21 |
| 2026-05-19 12:00 |
21:56:23.20 |
-15:18:27.2 |
HIP 108176 |
20.21 |
| 2026-05-20 00:00 |
21:56:23.19 |
-15:18:29.0 |
HIP 108176 |
20.21 |
| 2026-05-20 12:00 |
21:56:23.16 |
-15:18:30.9 |
HIP 108176 |
20.21 |
| 2026-05-21 00:00 |
21:56:23.12 |
-15:18:32.8 |
HIP 108176 |
20.21 |
| 2026-05-21 12:00 |
21:56:23.06 |
-15:18:34.9 |
HIP 108176 |
20.20 |
| 2026-05-22 00:00 |
21:56:22.99 |
-15:18:37.0 |
HIP 108176 |
20.19 |
| 2026-05-22 12:00 |
21:56:22.91 |
-15:18:39.2 |
HIP 108176 |
20.17 |
| 2026-05-23 00:00 |
21:56:22.81 |
-15:18:41.4 |
HIP 108176 |
20.16 |
| 2026-05-23 12:00 |
21:56:22.69 |
-15:18:43.8 |
HIP 108176 |
20.13 |
| 2026-05-24 00:00 |
21:56:22.56 |
-15:18:46.2 |
HIP 108176 |
20.11 |
| 2026-05-24 12:00 |
21:56:22.41 |
-15:18:48.7 |
HIP 108176 |
20.08 |
| 2026-05-25 00:00 |
21:56:22.25 |
-15:18:51.3 |
HIP 108176 |
20.05 |
| 2026-05-25 12:00 |
21:56:22.07 |
-15:18:54.0 |
HIP 108176 |
20.02 |
| 2026-05-26 00:00 |
21:56:21.88 |
-15:18:56.7 |
HIP 108176 |
19.98 |
| 2026-05-26 12:00 |
21:56:21.67 |
-15:18:59.6 |
HIP 108176 |
19.94 |
| 2026-05-27 00:00 |
21:56:21.45 |
-15:19:02.5 |
HIP 108176 |
19.89 |
| 2026-05-27 12:00 |
21:56:21.21 |
-15:19:05.5 |
HIP 108176 |
19.85 |
| 2026-05-28 00:00 |
21:56:20.96 |
-15:19:08.5 |
HIP 108176 |
19.79 |
| 2026-05-28 12:00 |
21:56:20.69 |
-15:19:11.6 |
HIP 108176 |
19.74 |
| 2026-05-29 00:00 |
21:56:20.41 |
-15:19:14.8 |
HIP 108176 |
19.68 |
| 2026-05-29 12:00 |
21:56:20.11 |
-15:19:18.1 |
HIP 108176 |
19.62 |
| 2026-05-30 00:00 |
21:56:19.80 |
-15:19:21.5 |
HIP 108176 |
19.56 |
| 2026-05-30 12:00 |
21:56:19.47 |
-15:19:24.9 |
HIP 108176 |
19.50 |
| 2026-05-31 00:00 |
21:56:19.13 |
-15:19:28.4 |
HIP 108176 |
19.43 |
| 2026-05-31 12:00 |
21:56:18.78 |
-15:19:32.0 |
HIP 108176 |
19.36 |
| 2026-06-01 00:00 |
21:56:18.40 |
-15:19:35.7 |
HIP 108176 |
19.28 |
| 2026-06-01 12:00 |
21:56:18.02 |
-15:19:39.4 |
HIP 108176 |
19.20 |
| 2026-06-02 00:00 |
21:56:17.62 |
-15:19:43.3 |
HIP 108176 |
19.12 |