| Parameter |
Value |
| Designation |
29P/Schwassmann-Wachmann 1 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2019-04-16T10:13:18.243840Z |
| Orbit solution date (soln_date, UTC) |
2025-04-14T15:28:00Z |
| Obs used |
739 |
| NEO |
- |
| M1 |
10.100 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2022-10-14.0000000 |
| e |
0.04479814 |
| q (au) |
5.775128 |
| a (au) |
6.045977 |
| i (deg) |
9.364771 |
| Ω (om, deg) |
312.390917 |
| ω (w, deg) |
50.662700 |
| M (ma, deg) |
84.635081 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.133 + 2.001\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.133 |
| n |
2.001 |
| gf |
0.913 |
| gb |
-0.737 |
| k |
0.800 |
| δ90 |
5.626 |
| 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 |
11:09:56.31 |
-02:17:15.2 |
HIP 54455 |
25.39 |
| 2026-03-26 12:00 |
11:09:44.29 |
-02:16:05.5 |
HIP 54455 |
22.23 |
| 2026-03-27 00:00 |
11:09:32.34 |
-02:14:55.9 |
HIP 54455 |
19.10 |
| 2026-03-27 12:00 |
11:09:20.46 |
-02:13:46.4 |
HIP 54455 |
16.02 |
| 2026-03-28 00:00 |
11:09:08.65 |
-02:12:36.9 |
HIP 54455 |
12.99 |
| 2026-03-28 12:00 |
11:08:56.91 |
-02:11:27.6 |
HIP 54455 |
10.08 |
| 2026-03-29 00:00 |
11:08:45.25 |
-02:10:18.3 |
HIP 54455 |
7.37 |
| 2026-03-29 12:00 |
11:08:33.67 |
-02:09:09.2 |
HIP 54455 |
5.17 |
| 2026-03-30 00:00 |
11:08:22.16 |
-02:08:00.2 |
HIP 54455 |
4.31 |
| 2026-03-30 12:00 |
11:08:10.73 |
-02:06:51.3 |
HIP 54455 |
5.42 |
| 2026-03-31 00:00 |
11:07:59.39 |
-02:05:42.6 |
HIP 54455 |
7.67 |
| 2026-03-31 12:00 |
11:07:48.12 |
-02:04:34.0 |
HIP 54371 |
8.08 |
| 2026-04-01 00:00 |
11:07:36.95 |
-02:03:25.7 |
HIP 54371 |
7.70 |
| 2026-04-01 12:00 |
11:07:25.85 |
-02:02:17.5 |
HIP 54371 |
8.45 |
| 2026-04-02 00:00 |
11:07:14.85 |
-02:01:09.5 |
HIP 54371 |
10.06 |
| 2026-04-02 12:00 |
11:07:03.94 |
-02:00:01.8 |
HIP 54371 |
12.19 |
| 2026-04-03 00:00 |
11:06:53.11 |
-01:58:54.2 |
HIP 54371 |
14.58 |
| 2026-04-03 12:00 |
11:06:42.38 |
-01:57:46.9 |
HIP 54371 |
17.13 |
| 2026-04-04 00:00 |
11:06:31.74 |
-01:56:39.9 |
HIP 54371 |
19.75 |
| 2026-04-04 12:00 |
11:06:21.20 |
-01:55:33.1 |
HIP 54371 |
22.42 |
| 2026-04-05 00:00 |
11:06:10.75 |
-01:54:26.5 |
HIP 54371 |
25.11 |
| 2026-04-05 12:00 |
11:06:00.40 |
-01:53:20.3 |
HIP 54371 |
27.81 |
| 2026-04-06 00:00 |
11:05:50.15 |
-01:52:14.3 |
HIP 54371 |
30.50 |
| 2026-04-06 12:00 |
11:05:40.00 |
-01:51:08.7 |
HIP 54371 |
33.19 |
| 2026-04-07 00:00 |
11:05:29.95 |
-01:50:03.3 |
HIP 54371 |
35.86 |
| 2026-04-07 12:00 |
11:05:20.01 |
-01:48:58.3 |
HIP 54041 |
33.72 |
| 2026-04-08 00:00 |
11:05:10.17 |
-01:47:53.6 |
HIP 54041 |
31.10 |
| 2026-04-08 12:00 |
11:05:00.44 |
-01:46:49.3 |
HIP 54041 |
28.52 |
| 2026-04-09 00:00 |
11:04:50.81 |
-01:45:45.3 |
HIP 54041 |
25.98 |
| 2026-04-09 12:00 |
11:04:41.29 |
-01:44:41.7 |
HIP 54041 |
23.49 |
| 2026-04-10 00:00 |
11:04:31.89 |
-01:43:38.4 |
HIP 54041 |
21.04 |
| 2026-04-10 12:00 |
11:04:22.59 |
-01:42:35.6 |
HIP 54041 |
18.66 |
| 2026-04-11 00:00 |
11:04:13.41 |
-01:41:33.2 |
HIP 54041 |
16.34 |
| 2026-04-11 12:00 |
11:04:04.34 |
-01:40:31.1 |
HIP 54041 |
14.12 |
| 2026-04-12 00:00 |
11:03:55.39 |
-01:39:29.5 |
HIP 54041 |
12.03 |
| 2026-04-12 12:00 |
11:03:46.55 |
-01:38:28.3 |
HIP 54041 |
10.13 |
| 2026-04-13 00:00 |
11:03:37.83 |
-01:37:27.6 |
HIP 54041 |
8.50 |
| 2026-04-13 12:00 |
11:03:29.23 |
-01:36:27.3 |
HIP 54041 |
7.33 |
| 2026-04-14 00:00 |
11:03:20.75 |
-01:35:27.5 |
HIP 54041 |
6.81 |
| 2026-04-14 12:00 |
11:03:12.39 |
-01:34:28.2 |
HIP 54041 |
7.06 |
| 2026-04-15 00:00 |
11:03:04.15 |
-01:33:29.3 |
HIP 54041 |
7.98 |
| 2026-04-15 12:00 |
11:02:56.04 |
-01:32:30.9 |
HIP 54041 |
9.34 |
| 2026-04-16 00:00 |
11:02:48.05 |
-01:31:33.1 |
HIP 54041 |
10.98 |