| 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) |
| 2026-09-20 00:00 |
17:12:32.93 |
+16:39:08.4 |
HIP 84096 |
20.28 |
| 2026-09-20 12:00 |
17:12:33.21 |
+16:38:41.2 |
HIP 84096 |
20.01 |
| 2026-09-21 00:00 |
17:12:33.51 |
+16:38:14.1 |
HIP 84096 |
19.75 |
| 2026-09-21 12:00 |
17:12:33.84 |
+16:37:47.0 |
HIP 84096 |
19.50 |
| 2026-09-22 00:00 |
17:12:34.19 |
+16:37:20.0 |
HIP 84096 |
19.26 |
| 2026-09-22 12:00 |
17:12:34.57 |
+16:36:52.9 |
HIP 84096 |
19.04 |
| 2026-09-23 00:00 |
17:12:34.98 |
+16:36:25.9 |
HIP 84096 |
18.83 |
| 2026-09-23 12:00 |
17:12:35.41 |
+16:35:58.9 |
HIP 84096 |
18.63 |
| 2026-09-24 00:00 |
17:12:35.86 |
+16:35:32.0 |
HIP 84096 |
18.45 |
| 2026-09-24 12:00 |
17:12:36.34 |
+16:35:05.1 |
HIP 84096 |
18.29 |
| 2026-09-25 00:00 |
17:12:36.85 |
+16:34:38.2 |
HIP 84096 |
18.14 |
| 2026-09-25 12:00 |
17:12:37.38 |
+16:34:11.4 |
HIP 84096 |
18.00 |
| 2026-09-26 00:00 |
17:12:37.93 |
+16:33:44.6 |
HIP 84096 |
17.88 |
| 2026-09-26 12:00 |
17:12:38.51 |
+16:33:17.8 |
HIP 84096 |
17.78 |
| 2026-09-27 00:00 |
17:12:39.12 |
+16:32:51.1 |
HIP 84096 |
17.70 |
| 2026-09-27 12:00 |
17:12:39.75 |
+16:32:24.5 |
HIP 84096 |
17.63 |
| 2026-09-28 00:00 |
17:12:40.40 |
+16:31:57.9 |
HIP 84096 |
17.59 |
| 2026-09-28 12:00 |
17:12:41.08 |
+16:31:31.3 |
HIP 84096 |
17.56 |
| 2026-09-29 00:00 |
17:12:41.78 |
+16:31:04.8 |
HIP 84096 |
17.55 |
| 2026-09-29 12:00 |
17:12:42.51 |
+16:30:38.3 |
HIP 84096 |
17.55 |
| 2026-09-30 00:00 |
17:12:43.26 |
+16:30:11.9 |
HIP 84096 |
17.58 |
| 2026-09-30 12:00 |
17:12:44.04 |
+16:29:45.6 |
HIP 84096 |
17.62 |
| 2026-10-01 00:00 |
17:12:44.84 |
+16:29:19.3 |
HIP 84096 |
17.69 |
| 2026-10-01 12:00 |
17:12:45.66 |
+16:28:53.1 |
HIP 84096 |
17.77 |
| 2026-10-02 00:00 |
17:12:46.51 |
+16:28:26.9 |
HIP 84096 |
17.87 |
| 2026-10-02 12:00 |
17:12:47.39 |
+16:28:00.8 |
HIP 84096 |
17.99 |
| 2026-10-03 00:00 |
17:12:48.28 |
+16:27:34.8 |
HIP 84293 |
17.92 |
| 2026-10-03 12:00 |
17:12:49.21 |
+16:27:08.8 |
HIP 84293 |
17.56 |
| 2026-10-04 00:00 |
17:12:50.15 |
+16:26:42.9 |
HIP 84293 |
17.20 |
| 2026-10-04 12:00 |
17:12:51.12 |
+16:26:17.1 |
HIP 84293 |
16.84 |
| 2026-10-05 00:00 |
17:12:52.11 |
+16:25:51.4 |
HIP 84293 |
16.48 |
| 2026-10-05 12:00 |
17:12:53.13 |
+16:25:25.7 |
HIP 84293 |
16.13 |
| 2026-10-06 00:00 |
17:12:54.17 |
+16:25:00.1 |
HIP 84293 |
15.78 |
| 2026-10-06 12:00 |
17:12:55.23 |
+16:24:34.6 |
HIP 84293 |
15.43 |
| 2026-10-07 00:00 |
17:12:56.32 |
+16:24:09.2 |
HIP 84293 |
15.08 |
| 2026-10-07 12:00 |
17:12:57.43 |
+16:23:43.8 |
HIP 84293 |
14.73 |
| 2026-10-08 00:00 |
17:12:58.56 |
+16:23:18.6 |
HIP 84293 |
14.39 |
| 2026-10-08 12:00 |
17:12:59.72 |
+16:22:53.4 |
HIP 84293 |
14.06 |
| 2026-10-09 00:00 |
17:13:00.90 |
+16:22:28.3 |
HIP 84293 |
13.73 |
| 2026-10-09 12:00 |
17:13:02.10 |
+16:22:03.3 |
HIP 84293 |
13.40 |
| 2026-10-10 00:00 |
17:13:03.33 |
+16:21:38.4 |
HIP 84293 |
13.08 |
| 2026-10-10 12:00 |
17:13:04.58 |
+16:21:13.6 |
HIP 84293 |
12.77 |
| 2026-10-11 00:00 |
17:13:05.85 |
+16:20:48.9 |
HIP 84293 |
12.47 |