| 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
$$
M_a = (10.899 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.899 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.713 |
| k |
0.800 |
| δ90 |
9.975 |
| 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 |
11:56:44.80 |
-06:26:40.3 |
HIP 58289 |
32.87 |
| 2026-09-20 12:00 |
11:57:05.17 |
-06:29:01.7 |
HIP 58289 |
29.72 |
| 2026-09-21 00:00 |
11:57:25.55 |
-06:31:23.3 |
HIP 58440 |
24.97 |
| 2026-09-21 12:00 |
11:57:45.93 |
-06:33:45.2 |
HIP 58440 |
19.43 |
| 2026-09-22 00:00 |
11:58:06.32 |
-06:36:07.2 |
HIP 58440 |
13.93 |
| 2026-09-22 12:00 |
11:58:26.71 |
-06:38:29.3 |
HIP 58440 |
8.55 |
| 2026-09-23 00:00 |
11:58:47.10 |
-06:40:51.7 |
HIP 58440 |
3.83 |
| 2026-09-23 12:00 |
11:59:07.49 |
-06:43:14.3 |
HIP 58440 |
4.32 |
| 2026-09-24 00:00 |
11:59:27.89 |
-06:45:37.0 |
HIP 58440 |
9.24 |
| 2026-09-24 12:00 |
11:59:48.28 |
-06:48:00.0 |
HIP 58440 |
14.65 |
| 2026-09-25 00:00 |
12:00:08.67 |
-06:50:23.0 |
HIP 58440 |
20.16 |
| 2026-09-25 12:00 |
12:00:29.07 |
-06:52:46.2 |
HIP 58440 |
25.72 |
| 2026-09-26 00:00 |
12:00:49.46 |
-06:55:09.6 |
HIP 58440 |
31.28 |
| 2026-09-26 12:00 |
12:01:09.85 |
-06:57:33.2 |
HIP 58440 |
36.86 |
| 2026-09-27 00:00 |
12:01:30.24 |
-06:59:56.9 |
HIP 58824 |
35.71 |
| 2026-09-27 12:00 |
12:01:50.63 |
-07:02:20.8 |
HIP 58824 |
31.11 |
| 2026-09-28 00:00 |
12:02:11.01 |
-07:04:44.8 |
HIP 58824 |
26.90 |
| 2026-09-28 12:00 |
12:02:31.40 |
-07:07:09.0 |
HIP 58824 |
23.28 |
| 2026-09-29 00:00 |
12:02:51.77 |
-07:09:33.3 |
HIP 58824 |
20.57 |
| 2026-09-29 12:00 |
12:03:12.15 |
-07:11:57.7 |
HIP 58824 |
19.16 |
| 2026-09-30 00:00 |
12:03:32.52 |
-07:14:22.3 |
HIP 58824 |
19.34 |
| 2026-09-30 12:00 |
12:03:52.88 |
-07:16:47.1 |
HIP 58824 |
21.06 |
| 2026-10-01 00:00 |
12:04:13.24 |
-07:19:11.9 |
HIP 58824 |
24.00 |
| 2026-10-01 12:00 |
12:04:33.59 |
-07:21:36.9 |
HIP 58824 |
27.77 |
| 2026-10-02 00:00 |
12:04:53.94 |
-07:24:02.1 |
HIP 58824 |
32.08 |
| 2026-10-02 12:00 |
12:05:14.27 |
-07:26:27.3 |
HIP 58898 |
33.00 |
| 2026-10-03 00:00 |
12:05:34.60 |
-07:28:52.7 |
HIP 58898 |
32.24 |
| 2026-10-03 12:00 |
12:05:54.93 |
-07:31:18.1 |
HIP 58898 |
32.44 |
| 2026-10-04 00:00 |
12:06:15.24 |
-07:33:43.7 |
HIP 58898 |
33.58 |
| 2026-10-04 12:00 |
12:06:35.54 |
-07:36:09.4 |
HIP 58898 |
35.57 |
| 2026-10-05 00:00 |
12:06:55.84 |
-07:38:35.2 |
HIP 58898 |
38.27 |
| 2026-10-05 12:00 |
12:07:16.12 |
-07:41:01.1 |
HIP 58898 |
41.54 |
| 2026-10-06 00:00 |
12:07:36.39 |
-07:43:27.1 |
HIP 59346 |
42.42 |
| 2026-10-06 12:00 |
12:07:56.65 |
-07:45:53.2 |
HIP 59346 |
37.29 |
| 2026-10-07 00:00 |
12:08:16.90 |
-07:48:19.4 |
HIP 59346 |
32.33 |
| 2026-10-07 12:00 |
12:08:37.13 |
-07:50:45.7 |
HIP 59346 |
27.60 |
| 2026-10-08 00:00 |
12:08:57.35 |
-07:53:12.0 |
HIP 59346 |
23.25 |
| 2026-10-08 12:00 |
12:09:17.56 |
-07:55:38.4 |
HIP 59346 |
19.55 |
| 2026-10-09 00:00 |
12:09:37.75 |
-07:58:04.9 |
HIP 59346 |
16.89 |
| 2026-10-09 12:00 |
12:09:57.93 |
-08:00:31.5 |
HIP 59346 |
15.84 |
| 2026-10-10 00:00 |
12:10:18.08 |
-08:02:58.1 |
HIP 59346 |
16.68 |
| 2026-10-10 12:00 |
12:10:38.22 |
-08:05:24.8 |
HIP 59346 |
19.17 |
| 2026-10-11 00:00 |
12:10:58.35 |
-08:07:51.5 |
HIP 59346 |
22.76 |