| Parameter |
Value |
| Designation |
C/2005 P3 (SWAN) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2005-08-09T17:53:55.314240Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:51Z |
| Obs used |
78 |
| NEO |
- |
| M1 |
13.000 |
| K1 |
9.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2005-09-05.0000000 |
| e |
0.98765964 |
| q (au) |
0.525760 |
| a (au) |
42.604934 |
| i (deg) |
89.706006 |
| Ω (om, deg) |
242.778577 |
| ω (w, deg) |
32.144830 |
| M (ma, deg) |
0.093049 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.682 + 2.791\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.682 |
| n |
2.791 |
| gf |
0.803 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
10.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
04:18:34.80 |
-00:20:44.8 |
HIP 19925 |
33.97 |
| 2026-05-12 12:00 |
04:18:37.70 |
-00:20:34.5 |
HIP 20073 |
34.68 |
| 2026-05-13 00:00 |
04:18:40.61 |
-00:20:24.2 |
HIP 20073 |
34.64 |
| 2026-05-13 12:00 |
04:18:43.53 |
-00:20:14.2 |
HIP 20073 |
34.62 |
| 2026-05-14 00:00 |
04:18:46.45 |
-00:20:04.2 |
HIP 20073 |
34.62 |
| 2026-05-14 12:00 |
04:18:49.38 |
-00:19:54.4 |
HIP 20073 |
34.63 |
| 2026-05-15 00:00 |
04:18:52.31 |
-00:19:44.7 |
HIP 20073 |
34.67 |
| 2026-05-15 12:00 |
04:18:55.25 |
-00:19:35.1 |
HIP 20073 |
34.72 |
| 2026-05-16 00:00 |
04:18:58.19 |
-00:19:25.6 |
HIP 20073 |
34.79 |
| 2026-05-16 12:00 |
04:19:01.14 |
-00:19:16.3 |
HIP 20073 |
34.88 |
| 2026-05-17 00:00 |
04:19:04.09 |
-00:19:07.1 |
HIP 20073 |
34.99 |
| 2026-05-17 12:00 |
04:19:07.05 |
-00:18:58.1 |
HIP 20282 |
34.83 |
| 2026-05-18 00:00 |
04:19:10.01 |
-00:18:49.2 |
HIP 20282 |
34.19 |
| 2026-05-18 12:00 |
04:19:12.98 |
-00:18:40.4 |
HIP 20282 |
33.55 |
| 2026-05-19 00:00 |
04:19:15.95 |
-00:18:31.7 |
HIP 20282 |
32.91 |
| 2026-05-19 12:00 |
04:19:18.92 |
-00:18:23.2 |
HIP 20282 |
32.29 |
| 2026-05-20 00:00 |
04:19:21.90 |
-00:18:14.8 |
HIP 20282 |
31.67 |
| 2026-05-20 12:00 |
04:19:24.88 |
-00:18:06.6 |
HIP 20282 |
31.06 |
| 2026-05-21 00:00 |
04:19:27.86 |
-00:17:58.5 |
HIP 20282 |
30.45 |
| 2026-05-21 12:00 |
04:19:30.84 |
-00:17:50.5 |
HIP 20282 |
29.85 |
| 2026-05-22 00:00 |
04:19:33.83 |
-00:17:42.7 |
HIP 20282 |
29.27 |
| 2026-05-22 12:00 |
04:19:36.82 |
-00:17:34.9 |
HIP 20282 |
28.69 |
| 2026-05-23 00:00 |
04:19:39.81 |
-00:17:27.4 |
HIP 20282 |
28.12 |
| 2026-05-23 12:00 |
04:19:42.81 |
-00:17:20.0 |
HIP 20282 |
27.56 |
| 2026-05-24 00:00 |
04:19:45.80 |
-00:17:12.7 |
HIP 20282 |
27.02 |
| 2026-05-24 12:00 |
04:19:48.80 |
-00:17:05.5 |
HIP 20282 |
26.48 |
| 2026-05-25 00:00 |
04:19:51.80 |
-00:16:58.5 |
HIP 20282 |
25.96 |
| 2026-05-25 12:00 |
04:19:54.80 |
-00:16:51.6 |
HIP 20282 |
25.45 |
| 2026-05-26 00:00 |
04:19:57.80 |
-00:16:44.9 |
HIP 20341 |
24.82 |
| 2026-05-26 12:00 |
04:20:00.80 |
-00:16:38.3 |
HIP 20341 |
24.10 |
| 2026-05-27 00:00 |
04:20:03.80 |
-00:16:31.9 |
HIP 20341 |
23.38 |
| 2026-05-27 12:00 |
04:20:06.81 |
-00:16:25.6 |
HIP 20341 |
22.67 |
| 2026-05-28 00:00 |
04:20:09.81 |
-00:16:19.4 |
HIP 20341 |
21.96 |
| 2026-05-28 12:00 |
04:20:12.81 |
-00:16:13.4 |
HIP 20341 |
21.25 |
| 2026-05-29 00:00 |
04:20:15.81 |
-00:16:07.5 |
HIP 20341 |
20.55 |
| 2026-05-29 12:00 |
04:20:18.81 |
-00:16:01.8 |
HIP 20341 |
19.85 |
| 2026-05-30 00:00 |
04:20:21.82 |
-00:15:56.2 |
HIP 20341 |
19.16 |
| 2026-05-30 12:00 |
04:20:24.82 |
-00:15:50.7 |
HIP 20341 |
18.48 |
| 2026-05-31 00:00 |
04:20:27.82 |
-00:15:45.4 |
HIP 20341 |
17.80 |
| 2026-05-31 12:00 |
04:20:30.81 |
-00:15:40.2 |
HIP 20341 |
17.14 |
| 2026-06-01 00:00 |
04:20:33.81 |
-00:15:35.2 |
HIP 20341 |
16.48 |
| 2026-06-01 12:00 |
04:20:36.81 |
-00:15:30.4 |
HIP 20341 |
15.83 |
| 2026-06-02 00:00 |
04:20:39.80 |
-00:15:25.6 |
HIP 20341 |
15.19 |