| 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 |
-0.501 |
| 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 |
02:15:10.87 |
+61:57:58.0 |
HIP 10409 |
18.53 |
| 2026-03-26 12:00 |
02:15:14.09 |
+61:57:50.9 |
HIP 10409 |
18.58 |
| 2026-03-27 00:00 |
02:15:17.32 |
+61:57:44.0 |
HIP 10409 |
18.65 |
| 2026-03-27 12:00 |
02:15:20.57 |
+61:57:37.3 |
HIP 10409 |
18.72 |
| 2026-03-28 00:00 |
02:15:23.83 |
+61:57:30.7 |
HIP 10409 |
18.81 |
| 2026-03-28 12:00 |
02:15:27.11 |
+61:57:24.4 |
HIP 10409 |
18.91 |
| 2026-03-29 00:00 |
02:15:30.41 |
+61:57:18.2 |
HIP 10409 |
19.02 |
| 2026-03-29 12:00 |
02:15:33.72 |
+61:57:12.2 |
HIP 10409 |
19.15 |
| 2026-03-30 00:00 |
02:15:37.04 |
+61:57:06.5 |
HIP 10409 |
19.28 |
| 2026-03-30 12:00 |
02:15:40.38 |
+61:57:00.8 |
HIP 10409 |
19.42 |
| 2026-03-31 00:00 |
02:15:43.73 |
+61:56:55.4 |
HIP 10409 |
19.58 |
| 2026-03-31 12:00 |
02:15:47.09 |
+61:56:50.2 |
HIP 10409 |
19.75 |
| 2026-04-01 00:00 |
02:15:50.47 |
+61:56:45.1 |
HIP 10409 |
19.92 |
| 2026-04-01 12:00 |
02:15:53.86 |
+61:56:40.3 |
HIP 10409 |
20.11 |
| 2026-04-02 00:00 |
02:15:57.26 |
+61:56:35.6 |
HIP 10409 |
20.31 |
| 2026-04-02 12:00 |
02:16:00.68 |
+61:56:31.1 |
HIP 10409 |
20.51 |
| 2026-04-03 00:00 |
02:16:04.11 |
+61:56:26.8 |
HIP 10409 |
20.73 |
| 2026-04-03 12:00 |
02:16:07.55 |
+61:56:22.7 |
HIP 10409 |
20.95 |
| 2026-04-04 00:00 |
02:16:11.00 |
+61:56:18.7 |
HIP 10409 |
21.18 |
| 2026-04-04 12:00 |
02:16:14.47 |
+61:56:15.0 |
HIP 10409 |
21.43 |
| 2026-04-05 00:00 |
02:16:17.95 |
+61:56:11.4 |
HIP 10409 |
21.68 |
| 2026-04-05 12:00 |
02:16:21.43 |
+61:56:08.0 |
HIP 10409 |
21.94 |
| 2026-04-06 00:00 |
02:16:24.93 |
+61:56:04.8 |
HIP 10409 |
22.20 |
| 2026-04-06 12:00 |
02:16:28.44 |
+61:56:01.8 |
HIP 10409 |
22.48 |
| 2026-04-07 00:00 |
02:16:31.96 |
+61:55:59.0 |
HIP 10409 |
22.76 |
| 2026-04-07 12:00 |
02:16:35.49 |
+61:55:56.4 |
HIP 10409 |
23.05 |
| 2026-04-08 00:00 |
02:16:39.04 |
+61:55:53.9 |
HIP 10409 |
23.34 |
| 2026-04-08 12:00 |
02:16:42.59 |
+61:55:51.7 |
HIP 10409 |
23.64 |
| 2026-04-09 00:00 |
02:16:46.15 |
+61:55:49.6 |
HIP 10409 |
23.95 |
| 2026-04-09 12:00 |
02:16:49.72 |
+61:55:47.7 |
HIP 10409 |
24.27 |
| 2026-04-10 00:00 |
02:16:53.30 |
+61:55:46.0 |
HIP 10409 |
24.59 |
| 2026-04-10 12:00 |
02:16:56.89 |
+61:55:44.5 |
HIP 10409 |
24.91 |
| 2026-04-11 00:00 |
02:17:00.48 |
+61:55:43.1 |
HIP 10409 |
25.24 |
| 2026-04-11 12:00 |
02:17:04.09 |
+61:55:42.0 |
HIP 10409 |
25.58 |
| 2026-04-12 00:00 |
02:17:07.70 |
+61:55:41.0 |
HIP 10409 |
25.92 |
| 2026-04-12 12:00 |
02:17:11.32 |
+61:55:40.3 |
HIP 10409 |
26.27 |
| 2026-04-13 00:00 |
02:17:14.95 |
+61:55:39.7 |
HIP 10409 |
26.62 |
| 2026-04-13 12:00 |
02:17:18.59 |
+61:55:39.3 |
HIP 10409 |
26.98 |
| 2026-04-14 00:00 |
02:17:22.23 |
+61:55:39.0 |
HIP 10409 |
27.34 |
| 2026-04-14 12:00 |
02:17:25.88 |
+61:55:39.0 |
HIP 10409 |
27.71 |
| 2026-04-15 00:00 |
02:17:29.54 |
+61:55:39.2 |
HIP 10409 |
28.07 |
| 2026-04-15 12:00 |
02:17:33.20 |
+61:55:39.5 |
HIP 10409 |
28.45 |
| 2026-04-16 00:00 |
02:17:36.88 |
+61:55:40.0 |
HIP 10409 |
28.83 |