| 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
$$
M_a = (10.875 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.875 |
| n |
2.000 |
| gf |
0.857 |
| gb |
-0.713 |
| k |
0.800 |
| δ90 |
7.952 |
| 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) |
| 2026-07-29 00:00 |
11:23:02.37 |
-02:48:00.7 |
HIP 55632 |
16.32 |
| 2026-07-29 12:00 |
11:23:19.15 |
-02:49:40.6 |
HIP 55632 |
15.12 |
| 2026-07-30 00:00 |
11:23:35.99 |
-02:51:21.1 |
HIP 55632 |
15.22 |
| 2026-07-30 12:00 |
11:23:52.90 |
-02:53:02.1 |
HIP 55632 |
16.62 |
| 2026-07-31 00:00 |
11:24:09.87 |
-02:54:43.7 |
HIP 55632 |
19.04 |
| 2026-07-31 12:00 |
11:24:26.90 |
-02:56:25.9 |
HIP 55632 |
22.16 |
| 2026-08-01 00:00 |
11:24:43.99 |
-02:58:08.6 |
HIP 55632 |
25.73 |
| 2026-08-01 12:00 |
11:25:01.14 |
-02:59:51.9 |
HIP 55609 |
27.77 |
| 2026-08-02 00:00 |
11:25:18.35 |
-03:01:35.7 |
HIP 55609 |
30.29 |
| 2026-08-02 12:00 |
11:25:35.62 |
-03:03:20.1 |
HIP 55609 |
33.27 |
| 2026-08-03 00:00 |
11:25:52.95 |
-03:05:05.0 |
HIP 55609 |
36.62 |
| 2026-08-03 12:00 |
11:26:10.34 |
-03:06:50.5 |
HIP 55609 |
40.24 |
| 2026-08-04 00:00 |
11:26:27.78 |
-03:08:36.5 |
HIP 56006 |
35.61 |
| 2026-08-04 12:00 |
11:26:45.28 |
-03:10:23.1 |
HIP 56006 |
30.89 |
| 2026-08-05 00:00 |
11:27:02.84 |
-03:12:10.1 |
HIP 56006 |
26.16 |
| 2026-08-05 12:00 |
11:27:20.46 |
-03:13:57.8 |
HIP 56006 |
21.41 |
| 2026-08-06 00:00 |
11:27:38.13 |
-03:15:45.9 |
HIP 56006 |
16.65 |
| 2026-08-06 12:00 |
11:27:55.86 |
-03:17:34.6 |
HIP 56006 |
11.88 |
| 2026-08-07 00:00 |
11:28:13.64 |
-03:19:23.8 |
HIP 56006 |
7.09 |
| 2026-08-07 12:00 |
11:28:31.47 |
-03:21:13.5 |
HIP 56006 |
2.33 |
| 2026-08-08 00:00 |
11:28:49.36 |
-03:23:03.7 |
HIP 56006 |
2.65 |
| 2026-08-08 12:00 |
11:29:07.30 |
-03:24:54.4 |
HIP 56006 |
7.44 |
| 2026-08-09 00:00 |
11:29:25.30 |
-03:26:45.7 |
HIP 56006 |
12.29 |
| 2026-08-09 12:00 |
11:29:43.34 |
-03:28:37.5 |
HIP 56006 |
17.16 |
| 2026-08-10 00:00 |
11:30:01.44 |
-03:30:29.7 |
HIP 56006 |
22.05 |
| 2026-08-10 12:00 |
11:30:19.59 |
-03:32:22.5 |
HIP 56006 |
26.95 |
| 2026-08-11 00:00 |
11:30:37.79 |
-03:34:15.8 |
HIP 56006 |
31.86 |
| 2026-08-11 12:00 |
11:30:56.04 |
-03:36:09.5 |
HIP 56006 |
36.80 |
| 2026-08-12 00:00 |
11:31:14.33 |
-03:38:03.8 |
HIP 56367 |
33.60 |
| 2026-08-12 12:00 |
11:31:32.68 |
-03:39:58.5 |
HIP 56367 |
30.45 |
| 2026-08-13 00:00 |
11:31:51.07 |
-03:41:53.8 |
HIP 56367 |
27.82 |
| 2026-08-13 12:00 |
11:32:09.51 |
-03:43:49.5 |
HIP 56367 |
25.90 |
| 2026-08-14 00:00 |
11:32:28.00 |
-03:45:45.6 |
HIP 56367 |
24.84 |
| 2026-08-14 12:00 |
11:32:46.53 |
-03:47:42.3 |
HIP 56367 |
24.77 |
| 2026-08-15 00:00 |
11:33:05.11 |
-03:49:39.4 |
HIP 56419 |
25.07 |
| 2026-08-15 12:00 |
11:33:23.73 |
-03:51:37.0 |
HIP 56419 |
20.92 |
| 2026-08-16 00:00 |
11:33:42.40 |
-03:53:35.0 |
HIP 56419 |
17.25 |
| 2026-08-16 12:00 |
11:34:01.10 |
-03:55:33.5 |
HIP 56419 |
14.43 |
| 2026-08-17 00:00 |
11:34:19.86 |
-03:57:32.4 |
HIP 56419 |
13.04 |
| 2026-08-17 12:00 |
11:34:38.65 |
-03:59:31.8 |
HIP 56419 |
13.54 |
| 2026-08-18 00:00 |
11:34:57.48 |
-04:01:31.6 |
HIP 56419 |
15.77 |
| 2026-08-18 12:00 |
11:35:16.36 |
-04:03:31.8 |
HIP 56500 |
18.65 |
| 2026-08-19 00:00 |
11:35:35.27 |
-04:05:32.5 |
HIP 56500 |
18.50 |