| 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 |
1.000 |
| gb |
-1.000 |
| k |
0.999 |
| 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 |
17:20:17.79 |
+17:32:36.4 |
HIP 84833 |
30.83 |
| 2026-06-01 12:00 |
17:20:14.53 |
+17:32:45.0 |
HIP 84833 |
30.70 |
| 2026-06-02 00:00 |
17:20:11.26 |
+17:32:53.3 |
HIP 84833 |
30.60 |
| 2026-06-02 12:00 |
17:20:07.99 |
+17:33:01.4 |
HIP 84833 |
30.52 |
| 2026-06-03 00:00 |
17:20:04.72 |
+17:33:09.2 |
HIP 84698 |
30.17 |
| 2026-06-03 12:00 |
17:20:01.44 |
+17:33:16.8 |
HIP 84698 |
29.62 |
| 2026-06-04 00:00 |
17:19:58.16 |
+17:33:24.1 |
HIP 84698 |
29.08 |
| 2026-06-04 12:00 |
17:19:54.88 |
+17:33:31.2 |
HIP 84698 |
28.56 |
| 2026-06-05 00:00 |
17:19:51.59 |
+17:33:38.1 |
HIP 84698 |
28.05 |
| 2026-06-05 12:00 |
17:19:48.30 |
+17:33:44.7 |
HIP 84698 |
27.56 |
| 2026-06-06 00:00 |
17:19:45.01 |
+17:33:51.0 |
HIP 84698 |
27.09 |
| 2026-06-06 12:00 |
17:19:41.71 |
+17:33:57.2 |
HIP 84698 |
26.63 |
| 2026-06-07 00:00 |
17:19:38.41 |
+17:34:03.0 |
HIP 84698 |
26.20 |
| 2026-06-07 12:00 |
17:19:35.11 |
+17:34:08.6 |
HIP 84698 |
25.78 |
| 2026-06-08 00:00 |
17:19:31.81 |
+17:34:14.0 |
HIP 84698 |
25.39 |
| 2026-06-08 12:00 |
17:19:28.50 |
+17:34:19.1 |
HIP 84698 |
25.02 |
| 2026-06-09 00:00 |
17:19:25.19 |
+17:34:24.0 |
HIP 84631 |
24.52 |
| 2026-06-09 12:00 |
17:19:21.89 |
+17:34:28.7 |
HIP 84631 |
23.96 |
| 2026-06-10 00:00 |
17:19:18.58 |
+17:34:33.0 |
HIP 84631 |
23.41 |
| 2026-06-10 12:00 |
17:19:15.27 |
+17:34:37.2 |
HIP 84631 |
22.87 |
| 2026-06-11 00:00 |
17:19:11.96 |
+17:34:41.1 |
HIP 84631 |
22.34 |
| 2026-06-11 12:00 |
17:19:08.65 |
+17:34:44.7 |
HIP 84631 |
21.83 |
| 2026-06-12 00:00 |
17:19:05.34 |
+17:34:48.1 |
HIP 84631 |
21.33 |
| 2026-06-12 12:00 |
17:19:02.03 |
+17:34:51.2 |
HIP 84631 |
20.84 |
| 2026-06-13 00:00 |
17:18:58.72 |
+17:34:54.1 |
HIP 84631 |
20.37 |
| 2026-06-13 12:00 |
17:18:55.41 |
+17:34:56.7 |
HIP 84631 |
19.92 |
| 2026-06-14 00:00 |
17:18:52.10 |
+17:34:59.1 |
HIP 84631 |
19.49 |
| 2026-06-14 12:00 |
17:18:48.80 |
+17:35:01.2 |
HIP 84631 |
19.07 |
| 2026-06-15 00:00 |
17:18:45.49 |
+17:35:03.1 |
HIP 84631 |
18.68 |
| 2026-06-15 12:00 |
17:18:42.19 |
+17:35:04.7 |
HIP 84631 |
18.30 |
| 2026-06-16 00:00 |
17:18:38.89 |
+17:35:06.1 |
HIP 84631 |
17.96 |
| 2026-06-16 12:00 |
17:18:35.59 |
+17:35:07.2 |
HIP 84631 |
17.63 |
| 2026-06-17 00:00 |
17:18:32.29 |
+17:35:08.1 |
HIP 84631 |
17.33 |
| 2026-06-17 12:00 |
17:18:29.00 |
+17:35:08.7 |
HIP 84631 |
17.06 |
| 2026-06-18 00:00 |
17:18:25.70 |
+17:35:09.1 |
HIP 84631 |
16.82 |
| 2026-06-18 12:00 |
17:18:22.42 |
+17:35:09.2 |
HIP 84631 |
16.61 |
| 2026-06-19 00:00 |
17:18:19.13 |
+17:35:09.1 |
HIP 84631 |
16.43 |
| 2026-06-19 12:00 |
17:18:15.85 |
+17:35:08.7 |
HIP 84631 |
16.28 |
| 2026-06-20 00:00 |
17:18:12.58 |
+17:35:08.0 |
HIP 84631 |
16.16 |
| 2026-06-20 12:00 |
17:18:09.30 |
+17:35:07.2 |
HIP 84631 |
16.08 |
| 2026-06-21 00:00 |
17:18:06.04 |
+17:35:06.0 |
HIP 84631 |
16.03 |
| 2026-06-21 12:00 |
17:18:02.77 |
+17:35:04.6 |
HIP 84631 |
16.01 |
| 2026-06-22 00:00 |
17:17:59.52 |
+17:35:03.0 |
HIP 84631 |
16.03 |