| Parameter |
Value |
| Designation |
198P/ODAS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2005-05-03T01:37:52.590720Z |
| Orbit solution date (soln_date, UTC) |
2024-11-14T12:12:28Z |
| Obs used |
200 |
| NEO |
- |
| M1 |
15.800 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2003-03-31.0000000 |
| e |
0.44765516 |
| q (au) |
1.979289 |
| a (au) |
3.583430 |
| i (deg) |
1.349850 |
| Ω (om, deg) |
358.743588 |
| ω (w, deg) |
69.062685 |
| M (ma, deg) |
248.983482 |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
07:06:57.65 |
+23:45:10.9 |
HIP 34317 |
13.05 |
| 2026-03-26 12:00 |
07:07:32.86 |
+23:43:51.7 |
HIP 34317 |
17.07 |
| 2026-03-27 00:00 |
07:08:08.30 |
+23:42:31.9 |
HIP 34317 |
23.40 |
| 2026-03-27 12:00 |
07:08:43.95 |
+23:41:11.3 |
HIP 34493 |
24.95 |
| 2026-03-28 00:00 |
07:09:19.81 |
+23:39:50.0 |
HIP 34493 |
24.46 |
| 2026-03-28 12:00 |
07:09:55.89 |
+23:38:28.0 |
HIP 34493 |
26.73 |
| 2026-03-29 00:00 |
07:10:32.17 |
+23:37:05.2 |
HIP 34775 |
22.61 |
| 2026-03-29 12:00 |
07:11:08.65 |
+23:35:41.7 |
HIP 34775 |
15.17 |
| 2026-03-30 00:00 |
07:11:45.34 |
+23:34:17.4 |
HIP 34775 |
9.63 |
| 2026-03-30 12:00 |
07:12:22.22 |
+23:32:52.4 |
HIP 34775 |
10.05 |
| 2026-03-31 00:00 |
07:12:59.30 |
+23:31:26.7 |
HIP 34775 |
16.05 |
| 2026-03-31 12:00 |
07:13:36.57 |
+23:30:00.2 |
HIP 34775 |
23.77 |
| 2026-04-01 00:00 |
07:14:14.04 |
+23:28:32.9 |
HIP 35074 |
19.38 |
| 2026-04-01 12:00 |
07:14:51.68 |
+23:27:04.9 |
HIP 35074 |
13.56 |
| 2026-04-02 00:00 |
07:15:29.52 |
+23:25:36.1 |
HIP 35074 |
12.08 |
| 2026-04-02 12:00 |
07:16:07.53 |
+23:24:06.5 |
HIP 35074 |
16.24 |
| 2026-04-03 00:00 |
07:16:45.73 |
+23:22:36.1 |
HIP 35074 |
23.24 |
| 2026-04-03 12:00 |
07:17:24.10 |
+23:21:05.0 |
HIP 35074 |
31.27 |
| 2026-04-04 00:00 |
07:18:02.64 |
+23:19:33.1 |
HIP 35074 |
39.72 |
| 2026-04-04 12:00 |
07:18:41.36 |
+23:18:00.4 |
HIP 35596 |
34.83 |
| 2026-04-05 00:00 |
07:19:20.25 |
+23:16:26.9 |
HIP 35596 |
29.09 |
| 2026-04-05 12:00 |
07:19:59.30 |
+23:14:52.6 |
HIP 35596 |
25.36 |
| 2026-04-06 00:00 |
07:20:38.52 |
+23:13:17.5 |
HIP 35596 |
24.61 |
| 2026-04-06 12:00 |
07:21:17.90 |
+23:11:41.6 |
HIP 35596 |
27.14 |
| 2026-04-07 00:00 |
07:21:57.44 |
+23:10:04.9 |
HIP 35842 |
24.77 |
| 2026-04-07 12:00 |
07:22:37.14 |
+23:08:27.4 |
HIP 35842 |
16.59 |
| 2026-04-08 00:00 |
07:23:17.00 |
+23:06:49.1 |
HIP 35842 |
10.41 |
| 2026-04-08 12:00 |
07:23:57.01 |
+23:05:10.0 |
HIP 35842 |
10.74 |
| 2026-04-09 00:00 |
07:24:37.18 |
+23:03:30.0 |
HIP 35930 |
8.35 |
| 2026-04-09 12:00 |
07:25:17.49 |
+23:01:49.2 |
HIP 35930 |
13.62 |
| 2026-04-10 00:00 |
07:25:57.95 |
+23:00:07.6 |
HIP 35930 |
21.93 |
| 2026-04-10 12:00 |
07:26:38.56 |
+22:58:25.1 |
HIP 36279 |
28.25 |
| 2026-04-11 00:00 |
07:27:19.31 |
+22:56:41.8 |
HIP 36279 |
20.87 |
| 2026-04-11 12:00 |
07:28:00.21 |
+22:54:57.7 |
HIP 36350 |
13.37 |
| 2026-04-12 00:00 |
07:28:41.24 |
+22:53:12.7 |
HIP 36350 |
4.95 |
| 2026-04-12 12:00 |
07:29:22.41 |
+22:51:26.9 |
HIP 36386 |
4.24 |
| 2026-04-13 00:00 |
07:30:03.72 |
+22:49:40.2 |
HIP 36386 |
10.76 |
| 2026-04-13 12:00 |
07:30:45.16 |
+22:47:52.7 |
HIP 36386 |
20.06 |
| 2026-04-14 00:00 |
07:31:26.74 |
+22:46:04.3 |
HIP 36691 |
20.56 |
| 2026-04-14 12:00 |
07:32:08.45 |
+22:44:15.1 |
HIP 36691 |
13.13 |
| 2026-04-15 00:00 |
07:32:50.28 |
+22:42:25.0 |
HIP 36708 |
9.48 |
| 2026-04-15 12:00 |
07:33:32.24 |
+22:40:34.0 |
HIP 36708 |
9.93 |
| 2026-04-16 00:00 |
07:34:14.33 |
+22:38:42.1 |
HIP 36708 |
17.40 |