| Parameter |
Value |
| Designation |
C/2000 Y2 (Skiff) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2001-03-21T19:21:55.632960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:08Z |
| Obs used |
159 |
| NEO |
- |
| M1 |
14.400 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2001-02-15.0000000 |
| e |
0.99434819 |
| q (au) |
2.768707 |
| a (au) |
489.879307 |
| i (deg) |
12.087438 |
| Ω (om, deg) |
185.848328 |
| ω (w, deg) |
326.817997 |
| M (ma, deg) |
359.996836 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.823 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.823 |
| n |
2.000 |
| gf |
0.942 |
| gb |
-1.000 |
| k |
0.999 |
| δ90 |
1.000 |
| 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 |
20:16:36.34 |
-08:45:32.7 |
HIP 100031 |
17.46 |
| 2026-09-20 12:00 |
20:16:35.04 |
-08:45:43.4 |
HIP 100031 |
17.70 |
| 2026-09-21 00:00 |
20:16:33.76 |
-08:45:54.1 |
HIP 100031 |
17.94 |
| 2026-09-21 12:00 |
20:16:32.50 |
-08:46:04.8 |
HIP 100031 |
18.18 |
| 2026-09-22 00:00 |
20:16:31.26 |
-08:46:15.4 |
HIP 100031 |
18.42 |
| 2026-09-22 12:00 |
20:16:30.03 |
-08:46:26.0 |
HIP 100031 |
18.66 |
| 2026-09-23 00:00 |
20:16:28.83 |
-08:46:36.6 |
HIP 100031 |
18.90 |
| 2026-09-23 12:00 |
20:16:27.64 |
-08:46:47.2 |
HIP 99829 |
19.13 |
| 2026-09-24 00:00 |
20:16:26.48 |
-08:46:57.7 |
HIP 99829 |
18.80 |
| 2026-09-24 12:00 |
20:16:25.33 |
-08:47:08.1 |
HIP 99829 |
18.47 |
| 2026-09-25 00:00 |
20:16:24.20 |
-08:47:18.6 |
HIP 99829 |
18.14 |
| 2026-09-25 12:00 |
20:16:23.09 |
-08:47:29.0 |
HIP 99829 |
17.82 |
| 2026-09-26 00:00 |
20:16:22.01 |
-08:47:39.4 |
HIP 99829 |
17.50 |
| 2026-09-26 12:00 |
20:16:20.94 |
-08:47:49.7 |
HIP 99829 |
17.19 |
| 2026-09-27 00:00 |
20:16:19.89 |
-08:48:00.0 |
HIP 99829 |
16.88 |
| 2026-09-27 12:00 |
20:16:18.86 |
-08:48:10.2 |
HIP 99829 |
16.57 |
| 2026-09-28 00:00 |
20:16:17.85 |
-08:48:20.5 |
HIP 99829 |
16.28 |
| 2026-09-28 12:00 |
20:16:16.86 |
-08:48:30.6 |
HIP 99829 |
15.98 |
| 2026-09-29 00:00 |
20:16:15.89 |
-08:48:40.8 |
HIP 99829 |
15.69 |
| 2026-09-29 12:00 |
20:16:14.94 |
-08:48:50.9 |
HIP 99829 |
15.41 |
| 2026-09-30 00:00 |
20:16:14.01 |
-08:49:00.9 |
HIP 99829 |
15.13 |
| 2026-09-30 12:00 |
20:16:13.10 |
-08:49:10.9 |
HIP 99829 |
14.86 |
| 2026-10-01 00:00 |
20:16:12.21 |
-08:49:20.9 |
HIP 99829 |
14.59 |
| 2026-10-01 12:00 |
20:16:11.34 |
-08:49:30.8 |
HIP 99829 |
14.32 |
| 2026-10-02 00:00 |
20:16:10.49 |
-08:49:40.7 |
HIP 99829 |
14.06 |
| 2026-10-02 12:00 |
20:16:09.67 |
-08:49:50.5 |
HIP 99829 |
13.81 |
| 2026-10-03 00:00 |
20:16:08.86 |
-08:50:00.3 |
HIP 99829 |
13.56 |
| 2026-10-03 12:00 |
20:16:08.07 |
-08:50:10.0 |
HIP 99829 |
13.32 |
| 2026-10-04 00:00 |
20:16:07.31 |
-08:50:19.7 |
HIP 99829 |
13.08 |
| 2026-10-04 12:00 |
20:16:06.56 |
-08:50:29.4 |
HIP 99829 |
12.85 |
| 2026-10-05 00:00 |
20:16:05.84 |
-08:50:38.9 |
HIP 99829 |
12.62 |
| 2026-10-05 12:00 |
20:16:05.14 |
-08:50:48.5 |
HIP 99829 |
12.40 |
| 2026-10-06 00:00 |
20:16:04.46 |
-08:50:58.0 |
HIP 99829 |
12.19 |
| 2026-10-06 12:00 |
20:16:03.80 |
-08:51:07.4 |
HIP 99829 |
11.98 |
| 2026-10-07 00:00 |
20:16:03.16 |
-08:51:16.8 |
HIP 99829 |
11.78 |
| 2026-10-07 12:00 |
20:16:02.54 |
-08:51:26.1 |
HIP 99829 |
11.58 |
| 2026-10-08 00:00 |
20:16:01.94 |
-08:51:35.4 |
HIP 99829 |
11.39 |
| 2026-10-08 12:00 |
20:16:01.37 |
-08:51:44.6 |
HIP 99829 |
11.20 |
| 2026-10-09 00:00 |
20:16:00.82 |
-08:51:53.8 |
HIP 99829 |
11.02 |
| 2026-10-09 12:00 |
20:16:00.28 |
-08:52:02.9 |
HIP 99829 |
10.85 |
| 2026-10-10 00:00 |
20:15:59.77 |
-08:52:11.9 |
HIP 99829 |
10.69 |
| 2026-10-10 12:00 |
20:15:59.29 |
-08:52:20.9 |
HIP 99829 |
10.53 |
| 2026-10-11 00:00 |
20:15:58.82 |
-08:52:29.9 |
HIP 99829 |
10.37 |