| 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) |
| 2026-09-20 00:00 |
11:27:04.04 |
+03:43:26.9 |
HIP 55852 |
9.20 |
| 2026-09-20 12:00 |
11:27:43.53 |
+03:39:08.3 |
HIP 55852 |
18.60 |
| 2026-09-21 00:00 |
11:28:22.97 |
+03:34:49.8 |
HIP 56073 |
21.76 |
| 2026-09-21 12:00 |
11:29:02.34 |
+03:30:31.6 |
HIP 56073 |
18.29 |
| 2026-09-22 00:00 |
11:29:41.67 |
+03:26:13.6 |
HIP 56102 |
14.56 |
| 2026-09-22 12:00 |
11:30:20.94 |
+03:21:55.8 |
HIP 56102 |
11.09 |
| 2026-09-23 00:00 |
11:31:00.15 |
+03:17:38.3 |
HIP 56209 |
15.04 |
| 2026-09-23 12:00 |
11:31:39.31 |
+03:13:21.0 |
HIP 56209 |
10.38 |
| 2026-09-24 00:00 |
11:32:18.41 |
+03:09:04.0 |
HIP 56209 |
14.73 |
| 2026-09-24 12:00 |
11:32:57.45 |
+03:04:47.1 |
HIP 56371 |
17.85 |
| 2026-09-25 00:00 |
11:33:36.44 |
+03:00:30.6 |
HIP 56445 |
11.81 |
| 2026-09-25 12:00 |
11:34:15.38 |
+02:56:14.3 |
HIP 56445 |
7.57 |
| 2026-09-26 00:00 |
11:34:54.25 |
+02:51:58.3 |
HIP 56513 |
3.74 |
| 2026-09-26 12:00 |
11:35:33.07 |
+02:47:42.5 |
HIP 56513 |
6.91 |
| 2026-09-27 00:00 |
11:36:11.84 |
+02:43:27.0 |
HIP 56513 |
17.47 |
| 2026-09-27 12:00 |
11:36:50.54 |
+02:39:11.7 |
HIP 56682 |
9.16 |
| 2026-09-28 00:00 |
11:37:29.19 |
+02:34:56.7 |
HIP 56682 |
2.57 |
| 2026-09-28 12:00 |
11:38:07.79 |
+02:30:42.0 |
HIP 56682 |
12.30 |
| 2026-09-29 00:00 |
11:38:46.32 |
+02:26:27.6 |
HIP 56682 |
22.74 |
| 2026-09-29 12:00 |
11:39:24.80 |
+02:22:13.5 |
HIP 56859 |
28.57 |
| 2026-09-30 00:00 |
11:40:03.22 |
+02:17:59.7 |
HIP 56859 |
33.91 |
| 2026-09-30 12:00 |
11:40:41.58 |
+02:13:46.1 |
HIP 57107 |
27.17 |
| 2026-10-01 00:00 |
11:41:19.89 |
+02:09:32.9 |
HIP 57107 |
20.44 |
| 2026-10-01 12:00 |
11:41:58.13 |
+02:05:19.9 |
HIP 57107 |
17.77 |
| 2026-10-02 00:00 |
11:42:36.32 |
+02:01:07.3 |
HIP 57107 |
20.78 |
| 2026-10-02 12:00 |
11:43:14.45 |
+01:56:54.9 |
HIP 57107 |
27.66 |
| 2026-10-03 00:00 |
11:43:52.52 |
+01:52:42.9 |
HIP 57315 |
25.63 |
| 2026-10-03 12:00 |
11:44:30.53 |
+01:48:31.2 |
HIP 57315 |
16.34 |
| 2026-10-04 00:00 |
11:45:08.48 |
+01:44:19.8 |
HIP 57315 |
9.64 |
| 2026-10-04 12:00 |
11:45:46.38 |
+01:40:08.8 |
HIP 57315 |
11.56 |
| 2026-10-05 00:00 |
11:46:24.21 |
+01:35:58.1 |
HIP 57315 |
19.70 |
| 2026-10-05 12:00 |
11:47:01.98 |
+01:31:47.7 |
HIP 57315 |
29.25 |
| 2026-10-06 00:00 |
11:47:39.69 |
+01:27:37.7 |
HIP 57525 |
33.35 |
| 2026-10-06 12:00 |
11:48:17.33 |
+01:23:28.0 |
HIP 57548 |
35.99 |
| 2026-10-07 00:00 |
11:48:54.92 |
+01:19:18.7 |
HIP 57548 |
35.58 |
| 2026-10-07 12:00 |
11:49:32.44 |
+01:15:09.7 |
HIP 57757 |
35.25 |
| 2026-10-08 00:00 |
11:50:09.90 |
+01:11:01.1 |
HIP 57757 |
35.77 |
| 2026-10-08 12:00 |
11:50:47.30 |
+01:06:52.9 |
HIP 57658 |
36.22 |
| 2026-10-09 00:00 |
11:51:24.63 |
+01:02:45.1 |
HIP 57658 |
39.17 |
| 2026-10-09 12:00 |
11:52:01.90 |
+00:58:37.7 |
HIP 58002 |
37.21 |
| 2026-10-10 00:00 |
11:52:39.10 |
+00:54:30.6 |
HIP 58002 |
27.82 |
| 2026-10-10 12:00 |
11:53:16.24 |
+00:50:24.0 |
HIP 58002 |
19.26 |
| 2026-10-11 00:00 |
11:53:53.31 |
+00:46:17.8 |
HIP 58002 |
13.19 |