C/2001 S1 (Skiff)
| Parameter |
Value |
| Designation |
C/2001 S1 (Skiff) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2001-06-02T08:44:15.699840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:11Z |
| Obs used |
39 |
| NEO |
- |
| M1 |
6.900 |
| K1 |
15.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2001-10-05.0000000 |
| e |
0.92987325 |
| q (au) |
3.749250 |
| a (au) |
53.463910 |
| i (deg) |
139.132817 |
| Ω (om, deg) |
330.121196 |
| ω (w, deg) |
285.171215 |
| M (ma, deg) |
0.314236 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.013 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.013 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-1.000 |
| k |
0.999 |
| δ90 |
9.998 |
| 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) |
| 2026-02-03 00:00 |
17:24:38.06 |
+15:58:02.8 |
HIP 85185 |
20.08 |
| 2026-02-03 12:00 |
17:24:39.78 |
+15:58:24.7 |
HIP 85185 |
19.75 |
| 2026-02-04 00:00 |
17:24:41.47 |
+15:58:46.7 |
HIP 85185 |
19.43 |
| 2026-02-04 12:00 |
17:24:43.15 |
+15:59:08.9 |
HIP 85185 |
19.12 |
| 2026-02-05 00:00 |
17:24:44.80 |
+15:59:31.2 |
HIP 85185 |
18.82 |
| 2026-02-05 12:00 |
17:24:46.43 |
+15:59:53.7 |
HIP 85185 |
18.52 |
| 2026-02-06 00:00 |
17:24:48.04 |
+16:00:16.4 |
HIP 85185 |
18.23 |
| 2026-02-06 12:00 |
17:24:49.63 |
+16:00:39.2 |
HIP 85185 |
17.94 |
| 2026-02-07 00:00 |
17:24:51.19 |
+16:01:02.2 |
HIP 85185 |
17.67 |
| 2026-02-07 12:00 |
17:24:52.74 |
+16:01:25.4 |
HIP 85185 |
17.40 |
| 2026-02-08 00:00 |
17:24:54.26 |
+16:01:48.7 |
HIP 85185 |
17.14 |
| 2026-02-08 12:00 |
17:24:55.76 |
+16:02:12.2 |
HIP 85185 |
16.89 |
| 2026-02-09 00:00 |
17:24:57.24 |
+16:02:35.8 |
HIP 85185 |
16.65 |
| 2026-02-09 12:00 |
17:24:58.69 |
+16:02:59.6 |
HIP 85185 |
16.42 |
| 2026-02-10 00:00 |
17:25:00.12 |
+16:03:23.5 |
HIP 85185 |
16.20 |
| 2026-02-10 12:00 |
17:25:01.54 |
+16:03:47.6 |
HIP 85185 |
15.99 |
| 2026-02-11 00:00 |
17:25:02.92 |
+16:04:11.8 |
HIP 85185 |
15.78 |
| 2026-02-11 12:00 |
17:25:04.29 |
+16:04:36.2 |
HIP 85185 |
15.59 |
| 2026-02-12 00:00 |
17:25:05.63 |
+16:05:00.7 |
HIP 85185 |
15.41 |
| 2026-02-12 12:00 |
17:25:06.95 |
+16:05:25.3 |
HIP 85185 |
15.24 |
| 2026-02-13 00:00 |
17:25:08.24 |
+16:05:50.1 |
HIP 85185 |
15.07 |
| 2026-02-13 12:00 |
17:25:09.51 |
+16:06:15.1 |
HIP 85185 |
14.92 |
| 2026-02-14 00:00 |
17:25:10.76 |
+16:06:40.2 |
HIP 85185 |
14.78 |
| 2026-02-14 12:00 |
17:25:11.98 |
+16:07:05.4 |
HIP 85185 |
14.65 |
| 2026-02-15 00:00 |
17:25:13.18 |
+16:07:30.7 |
HIP 85185 |
14.54 |
| 2026-02-15 12:00 |
17:25:14.36 |
+16:07:56.2 |
HIP 85185 |
14.43 |
| 2026-02-16 00:00 |
17:25:15.51 |
+16:08:21.8 |
HIP 85185 |
14.34 |
| 2026-02-16 12:00 |
17:25:16.63 |
+16:08:47.5 |
HIP 85185 |
14.25 |
| 2026-02-17 00:00 |
17:25:17.74 |
+16:09:13.4 |
HIP 85185 |
14.18 |
| 2026-02-17 12:00 |
17:25:18.81 |
+16:09:39.4 |
HIP 85185 |
14.12 |
| 2026-02-18 00:00 |
17:25:19.87 |
+16:10:05.5 |
HIP 85289 |
13.89 |
| 2026-02-18 12:00 |
17:25:20.90 |
+16:10:31.7 |
HIP 85289 |
13.39 |
| 2026-02-19 00:00 |
17:25:21.90 |
+16:10:58.1 |
HIP 85289 |
12.90 |
| 2026-02-19 12:00 |
17:25:22.88 |
+16:11:24.6 |
HIP 85289 |
12.40 |
| 2026-02-20 00:00 |
17:25:23.83 |
+16:11:51.1 |
HIP 85289 |
11.91 |
| 2026-02-20 12:00 |
17:25:24.76 |
+16:12:17.8 |
HIP 85289 |
11.41 |
| 2026-02-21 00:00 |
17:25:25.66 |
+16:12:44.6 |
HIP 85289 |
10.92 |
| 2026-02-21 12:00 |
17:25:26.54 |
+16:13:11.5 |
HIP 85289 |
10.43 |
| 2026-02-22 00:00 |
17:25:27.40 |
+16:13:38.6 |
HIP 85289 |
9.93 |
| 2026-02-22 12:00 |
17:25:28.22 |
+16:14:05.7 |
HIP 85289 |
9.44 |
| 2026-02-23 00:00 |
17:25:29.02 |
+16:14:32.9 |
HIP 85289 |
8.95 |
| 2026-02-23 12:00 |
17:25:29.80 |
+16:15:00.2 |
HIP 85289 |
8.46 |
| 2026-02-24 00:00 |
17:25:30.55 |
+16:15:27.6 |
HIP 85289 |
7.97 |