| 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) |
| 2026-07-29 00:00 |
20:20:11.35 |
-08:26:45.5 |
HIP 100235 |
6.31 |
| 2026-07-29 12:00 |
20:20:08.91 |
-08:26:54.5 |
HIP 100235 |
5.70 |
| 2026-07-30 00:00 |
20:20:06.48 |
-08:27:03.6 |
HIP 100235 |
5.10 |
| 2026-07-30 12:00 |
20:20:04.04 |
-08:27:12.7 |
HIP 100235 |
4.49 |
| 2026-07-31 00:00 |
20:20:01.61 |
-08:27:21.9 |
HIP 100235 |
3.90 |
| 2026-07-31 12:00 |
20:19:59.18 |
-08:27:31.1 |
HIP 100235 |
3.31 |
| 2026-08-01 00:00 |
20:19:56.76 |
-08:27:40.4 |
HIP 100235 |
2.74 |
| 2026-08-01 12:00 |
20:19:54.33 |
-08:27:49.7 |
HIP 100235 |
2.19 |
| 2026-08-02 00:00 |
20:19:51.91 |
-08:27:59.1 |
HIP 100235 |
1.70 |
| 2026-08-02 12:00 |
20:19:49.49 |
-08:28:08.6 |
HIP 100235 |
1.32 |
| 2026-08-03 00:00 |
20:19:47.07 |
-08:28:18.1 |
HIP 100235 |
1.16 |
| 2026-08-03 12:00 |
20:19:44.66 |
-08:28:27.6 |
HIP 100235 |
1.32 |
| 2026-08-04 00:00 |
20:19:42.25 |
-08:28:37.2 |
HIP 100235 |
1.70 |
| 2026-08-04 12:00 |
20:19:39.84 |
-08:28:46.8 |
HIP 100235 |
2.19 |
| 2026-08-05 00:00 |
20:19:37.44 |
-08:28:56.5 |
HIP 100235 |
2.73 |
| 2026-08-05 12:00 |
20:19:35.04 |
-08:29:06.3 |
HIP 100235 |
3.30 |
| 2026-08-06 00:00 |
20:19:32.65 |
-08:29:16.1 |
HIP 100235 |
3.88 |
| 2026-08-06 12:00 |
20:19:30.26 |
-08:29:25.9 |
HIP 100235 |
4.47 |
| 2026-08-07 00:00 |
20:19:27.87 |
-08:29:35.8 |
HIP 100235 |
5.07 |
| 2026-08-07 12:00 |
20:19:25.49 |
-08:29:45.8 |
HIP 100235 |
5.67 |
| 2026-08-08 00:00 |
20:19:23.11 |
-08:29:55.7 |
HIP 100235 |
6.27 |
| 2026-08-08 12:00 |
20:19:20.74 |
-08:30:05.8 |
HIP 100235 |
6.87 |
| 2026-08-09 00:00 |
20:19:18.37 |
-08:30:15.8 |
HIP 100235 |
7.47 |
| 2026-08-09 12:00 |
20:19:16.01 |
-08:30:26.0 |
HIP 100235 |
8.07 |
| 2026-08-10 00:00 |
20:19:13.65 |
-08:30:36.1 |
HIP 100235 |
8.67 |
| 2026-08-10 12:00 |
20:19:11.30 |
-08:30:46.3 |
HIP 100235 |
9.28 |
| 2026-08-11 00:00 |
20:19:08.96 |
-08:30:56.6 |
HIP 100235 |
9.88 |
| 2026-08-11 12:00 |
20:19:06.62 |
-08:31:06.8 |
HIP 100235 |
10.48 |
| 2026-08-12 00:00 |
20:19:04.28 |
-08:31:17.2 |
HIP 100235 |
11.08 |
| 2026-08-12 12:00 |
20:19:01.96 |
-08:31:27.5 |
HIP 100235 |
11.67 |
| 2026-08-13 00:00 |
20:18:59.64 |
-08:31:37.9 |
HIP 100235 |
12.27 |
| 2026-08-13 12:00 |
20:18:57.33 |
-08:31:48.3 |
HIP 100235 |
12.87 |
| 2026-08-14 00:00 |
20:18:55.02 |
-08:31:58.8 |
HIP 100235 |
13.46 |
| 2026-08-14 12:00 |
20:18:52.73 |
-08:32:09.3 |
HIP 100235 |
14.05 |
| 2026-08-15 00:00 |
20:18:50.44 |
-08:32:19.9 |
HIP 100235 |
14.64 |
| 2026-08-15 12:00 |
20:18:48.16 |
-08:32:30.4 |
HIP 100235 |
15.24 |
| 2026-08-16 00:00 |
20:18:45.88 |
-08:32:41.0 |
HIP 100235 |
15.82 |
| 2026-08-16 12:00 |
20:18:43.62 |
-08:32:51.7 |
HIP 100235 |
16.41 |
| 2026-08-17 00:00 |
20:18:41.36 |
-08:33:02.3 |
HIP 100235 |
17.00 |
| 2026-08-17 12:00 |
20:18:39.11 |
-08:33:13.0 |
HIP 100235 |
17.58 |
| 2026-08-18 00:00 |
20:18:36.87 |
-08:33:23.7 |
HIP 100235 |
18.16 |
| 2026-08-18 12:00 |
20:18:34.64 |
-08:33:34.5 |
HIP 100235 |
18.74 |
| 2026-08-19 00:00 |
20:18:32.42 |
-08:33:45.2 |
HIP 100235 |
19.32 |