| Parameter |
Value |
| Designation |
C/1987 F1 (Torres) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1987-04-10T04:42:36.086400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:33Z |
| Obs used |
50 |
| NEO |
- |
| M1 |
7.600 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1988-01-19.0000000 |
| e |
1.00120894 |
| q (au) |
3.624287 |
| a (au) |
-2997.904748 |
| i (deg) |
124.078713 |
| Ω (om, deg) |
194.487430 |
| ω (w, deg) |
329.070992 |
| M (ma, deg) |
0.001704 |
Magnitude
Scatter + Global Linear
$$
M_a = (3.446 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
3.446 |
| 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 |
02:23:06.90 |
+62:08:27.2 |
HIP 11118 |
4.60 |
| 2026-06-01 12:00 |
02:23:10.05 |
+62:08:42.3 |
HIP 11118 |
4.42 |
| 2026-06-02 00:00 |
02:23:13.19 |
+62:08:57.5 |
HIP 11118 |
4.29 |
| 2026-06-02 12:00 |
02:23:16.31 |
+62:09:12.9 |
HIP 11118 |
4.19 |
| 2026-06-03 00:00 |
02:23:19.41 |
+62:09:28.3 |
HIP 11118 |
4.14 |
| 2026-06-03 12:00 |
02:23:22.50 |
+62:09:43.9 |
HIP 11118 |
4.13 |
| 2026-06-04 00:00 |
02:23:25.57 |
+62:09:59.6 |
HIP 11118 |
4.17 |
| 2026-06-04 12:00 |
02:23:28.62 |
+62:10:15.4 |
HIP 11118 |
4.25 |
| 2026-06-05 00:00 |
02:23:31.65 |
+62:10:31.3 |
HIP 11118 |
4.37 |
| 2026-06-05 12:00 |
02:23:34.67 |
+62:10:47.3 |
HIP 11118 |
4.53 |
| 2026-06-06 00:00 |
02:23:37.67 |
+62:11:03.4 |
HIP 11118 |
4.72 |
| 2026-06-06 12:00 |
02:23:40.65 |
+62:11:19.7 |
HIP 11118 |
4.94 |
| 2026-06-07 00:00 |
02:23:43.61 |
+62:11:36.0 |
HIP 11118 |
5.19 |
| 2026-06-07 12:00 |
02:23:46.55 |
+62:11:52.5 |
HIP 11118 |
5.45 |
| 2026-06-08 00:00 |
02:23:49.48 |
+62:12:09.0 |
HIP 11118 |
5.74 |
| 2026-06-08 12:00 |
02:23:52.38 |
+62:12:25.7 |
HIP 11118 |
6.04 |
| 2026-06-09 00:00 |
02:23:55.27 |
+62:12:42.4 |
HIP 11118 |
6.36 |
| 2026-06-09 12:00 |
02:23:58.14 |
+62:12:59.3 |
HIP 11118 |
6.69 |
| 2026-06-10 00:00 |
02:24:00.98 |
+62:13:16.2 |
HIP 11118 |
7.02 |
| 2026-06-10 12:00 |
02:24:03.81 |
+62:13:33.3 |
HIP 11118 |
7.37 |
| 2026-06-11 00:00 |
02:24:06.62 |
+62:13:50.4 |
HIP 11118 |
7.72 |
| 2026-06-11 12:00 |
02:24:09.40 |
+62:14:07.7 |
HIP 11118 |
8.08 |
| 2026-06-12 00:00 |
02:24:12.17 |
+62:14:25.1 |
HIP 11118 |
8.44 |
| 2026-06-12 12:00 |
02:24:14.91 |
+62:14:42.5 |
HIP 11118 |
8.80 |
| 2026-06-13 00:00 |
02:24:17.64 |
+62:15:00.0 |
HIP 11118 |
9.17 |
| 2026-06-13 12:00 |
02:24:20.34 |
+62:15:17.7 |
HIP 11118 |
9.55 |
| 2026-06-14 00:00 |
02:24:23.02 |
+62:15:35.4 |
HIP 11118 |
9.92 |
| 2026-06-14 12:00 |
02:24:25.68 |
+62:15:53.2 |
HIP 11118 |
10.30 |
| 2026-06-15 00:00 |
02:24:28.32 |
+62:16:11.1 |
HIP 11166 |
10.22 |
| 2026-06-15 12:00 |
02:24:30.94 |
+62:16:29.1 |
HIP 11166 |
10.13 |
| 2026-06-16 00:00 |
02:24:33.53 |
+62:16:47.1 |
HIP 11166 |
10.04 |
| 2026-06-16 12:00 |
02:24:36.10 |
+62:17:05.3 |
HIP 11166 |
9.98 |
| 2026-06-17 00:00 |
02:24:38.65 |
+62:17:23.5 |
HIP 11166 |
9.92 |
| 2026-06-17 12:00 |
02:24:41.18 |
+62:17:41.8 |
HIP 11166 |
9.89 |
| 2026-06-18 00:00 |
02:24:43.68 |
+62:18:00.2 |
HIP 11166 |
9.86 |
| 2026-06-18 12:00 |
02:24:46.16 |
+62:18:18.7 |
HIP 11166 |
9.85 |
| 2026-06-19 00:00 |
02:24:48.61 |
+62:18:37.3 |
HIP 11166 |
9.86 |
| 2026-06-19 12:00 |
02:24:51.04 |
+62:18:55.9 |
HIP 11254 |
9.62 |
| 2026-06-20 00:00 |
02:24:53.45 |
+62:19:14.6 |
HIP 11254 |
9.31 |
| 2026-06-20 12:00 |
02:24:55.84 |
+62:19:33.4 |
HIP 11254 |
9.00 |
| 2026-06-21 00:00 |
02:24:58.20 |
+62:19:52.2 |
HIP 11254 |
8.71 |
| 2026-06-21 12:00 |
02:25:00.53 |
+62:20:11.1 |
HIP 11254 |
8.42 |
| 2026-06-22 00:00 |
02:25:02.84 |
+62:20:30.1 |
HIP 11254 |
8.15 |