| Parameter |
Value |
| Designation |
C/2015 P3 (SWAN) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-07-27T19:07:02.274240Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:13Z |
| Obs used |
132 |
| NEO |
- |
| M1 |
16.300 |
| K1 |
10.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-08-17.0000000 |
| e |
0.99710074 |
| q (au) |
0.715220 |
| a (au) |
246.691015 |
| i (deg) |
58.183707 |
| Ω (om, deg) |
88.145306 |
| ω (w, deg) |
132.872099 |
| M (ma, deg) |
0.005139 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.714 + 5.525\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.714 |
| n |
5.525 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.800 |
| 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) |
| 2026-07-29 00:00 |
03:44:54.76 |
-32:23:14.8 |
HIP 17569 |
12.12 |
| 2026-07-29 12:00 |
03:44:56.74 |
-32:23:56.8 |
HIP 17569 |
11.44 |
| 2026-07-30 00:00 |
03:44:58.69 |
-32:24:39.0 |
HIP 17569 |
10.77 |
| 2026-07-30 12:00 |
03:45:00.59 |
-32:25:21.5 |
HIP 17569 |
10.13 |
| 2026-07-31 00:00 |
03:45:02.46 |
-32:26:04.3 |
HIP 17569 |
9.53 |
| 2026-07-31 12:00 |
03:45:04.29 |
-32:26:47.2 |
HIP 17569 |
8.97 |
| 2026-08-01 00:00 |
03:45:06.08 |
-32:27:30.4 |
HIP 17569 |
8.46 |
| 2026-08-01 12:00 |
03:45:07.83 |
-32:28:13.9 |
HIP 17569 |
8.00 |
| 2026-08-02 00:00 |
03:45:09.54 |
-32:28:57.5 |
HIP 17569 |
7.61 |
| 2026-08-02 12:00 |
03:45:11.22 |
-32:29:41.4 |
HIP 17569 |
7.30 |
| 2026-08-03 00:00 |
03:45:12.85 |
-32:30:25.5 |
HIP 17569 |
7.09 |
| 2026-08-03 12:00 |
03:45:14.44 |
-32:31:09.8 |
HIP 17569 |
6.96 |
| 2026-08-04 00:00 |
03:45:16.00 |
-32:31:54.4 |
HIP 17542 |
6.51 |
| 2026-08-04 12:00 |
03:45:17.51 |
-32:32:39.1 |
HIP 17542 |
5.71 |
| 2026-08-05 00:00 |
03:45:18.99 |
-32:33:24.0 |
HIP 17542 |
4.92 |
| 2026-08-05 12:00 |
03:45:20.43 |
-32:34:09.2 |
HIP 17542 |
4.13 |
| 2026-08-06 00:00 |
03:45:21.82 |
-32:34:54.6 |
HIP 17542 |
3.34 |
| 2026-08-06 12:00 |
03:45:23.18 |
-32:35:40.1 |
HIP 17542 |
2.57 |
| 2026-08-07 00:00 |
03:45:24.49 |
-32:36:25.9 |
HIP 17542 |
1.83 |
| 2026-08-07 12:00 |
03:45:25.76 |
-32:37:11.8 |
HIP 17542 |
1.18 |
| 2026-08-08 00:00 |
03:45:27.00 |
-32:37:58.0 |
HIP 17542 |
0.85 |
| 2026-08-08 12:00 |
03:45:28.19 |
-32:38:44.3 |
HIP 17542 |
1.17 |
| 2026-08-09 00:00 |
03:45:29.34 |
-32:39:30.8 |
HIP 17542 |
1.82 |
| 2026-08-09 12:00 |
03:45:30.45 |
-32:40:17.5 |
HIP 17542 |
2.56 |
| 2026-08-10 00:00 |
03:45:31.52 |
-32:41:04.4 |
HIP 17542 |
3.33 |
| 2026-08-10 12:00 |
03:45:32.54 |
-32:41:51.4 |
HIP 17542 |
4.12 |
| 2026-08-11 00:00 |
03:45:33.53 |
-32:42:38.6 |
HIP 17542 |
4.91 |
| 2026-08-11 12:00 |
03:45:34.47 |
-32:43:26.0 |
HIP 17542 |
5.71 |
| 2026-08-12 00:00 |
03:45:35.37 |
-32:44:13.6 |
HIP 17542 |
6.51 |
| 2026-08-12 12:00 |
03:45:36.23 |
-32:45:01.3 |
HIP 17542 |
7.32 |
| 2026-08-13 00:00 |
03:45:37.05 |
-32:45:49.1 |
HIP 17542 |
8.12 |
| 2026-08-13 12:00 |
03:45:37.82 |
-32:46:37.2 |
HIP 17542 |
8.93 |
| 2026-08-14 00:00 |
03:45:38.55 |
-32:47:25.3 |
HIP 17542 |
9.74 |
| 2026-08-14 12:00 |
03:45:39.24 |
-32:48:13.6 |
HIP 17542 |
10.54 |
| 2026-08-15 00:00 |
03:45:39.89 |
-32:49:02.1 |
HIP 17542 |
11.35 |
| 2026-08-15 12:00 |
03:45:40.49 |
-32:49:50.6 |
HIP 17542 |
12.16 |
| 2026-08-16 00:00 |
03:45:41.05 |
-32:50:39.4 |
HIP 17542 |
12.97 |
| 2026-08-16 12:00 |
03:45:41.57 |
-32:51:28.2 |
HIP 17542 |
13.78 |
| 2026-08-17 00:00 |
03:45:42.05 |
-32:52:17.2 |
HIP 17542 |
14.60 |
| 2026-08-17 12:00 |
03:45:42.48 |
-32:53:06.2 |
HIP 17542 |
15.41 |
| 2026-08-18 00:00 |
03:45:42.87 |
-32:53:55.4 |
HIP 17542 |
16.22 |
| 2026-08-18 12:00 |
03:45:43.22 |
-32:54:44.8 |
HIP 17542 |
17.04 |
| 2026-08-19 00:00 |
03:45:43.52 |
-32:55:34.2 |
HIP 17542 |
17.85 |