| 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 |
0.999 |
| 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) |
| 2026-03-26 00:00 |
03:27:20.22 |
-32:37:51.2 |
HIP 16125 |
23.78 |
| 2026-03-26 12:00 |
03:27:23.68 |
-32:37:02.7 |
HIP 16125 |
22.86 |
| 2026-03-27 00:00 |
03:27:27.17 |
-32:36:14.5 |
HIP 16125 |
21.95 |
| 2026-03-27 12:00 |
03:27:30.70 |
-32:35:26.5 |
HIP 16125 |
21.07 |
| 2026-03-28 00:00 |
03:27:34.25 |
-32:34:38.8 |
HIP 16125 |
20.20 |
| 2026-03-28 12:00 |
03:27:37.83 |
-32:33:51.4 |
HIP 16125 |
19.37 |
| 2026-03-29 00:00 |
03:27:41.44 |
-32:33:04.2 |
HIP 16125 |
18.57 |
| 2026-03-29 12:00 |
03:27:45.08 |
-32:32:17.2 |
HIP 16125 |
17.80 |
| 2026-03-30 00:00 |
03:27:48.75 |
-32:31:30.5 |
HIP 16125 |
17.08 |
| 2026-03-30 12:00 |
03:27:52.44 |
-32:30:44.1 |
HIP 16125 |
16.40 |
| 2026-03-31 00:00 |
03:27:56.17 |
-32:29:57.9 |
HIP 16125 |
15.77 |
| 2026-03-31 12:00 |
03:27:59.92 |
-32:29:12.0 |
HIP 16125 |
15.21 |
| 2026-04-01 00:00 |
03:28:03.70 |
-32:28:26.4 |
HIP 16125 |
14.71 |
| 2026-04-01 12:00 |
03:28:07.51 |
-32:27:41.1 |
HIP 16125 |
14.28 |
| 2026-04-02 00:00 |
03:28:11.34 |
-32:26:56.0 |
HIP 16125 |
13.94 |
| 2026-04-02 12:00 |
03:28:15.21 |
-32:26:11.2 |
HIP 16125 |
13.68 |
| 2026-04-03 00:00 |
03:28:19.09 |
-32:25:26.7 |
HIP 16125 |
13.52 |
| 2026-04-03 12:00 |
03:28:23.01 |
-32:24:42.4 |
HIP 16125 |
13.45 |
| 2026-04-04 00:00 |
03:28:26.95 |
-32:23:58.4 |
HIP 16125 |
13.49 |
| 2026-04-04 12:00 |
03:28:30.92 |
-32:23:14.8 |
HIP 16125 |
13.62 |
| 2026-04-05 00:00 |
03:28:34.91 |
-32:22:31.4 |
HIP 16125 |
13.84 |
| 2026-04-05 12:00 |
03:28:38.93 |
-32:21:48.3 |
HIP 16125 |
14.16 |
| 2026-04-06 00:00 |
03:28:42.97 |
-32:21:05.5 |
HIP 16125 |
14.56 |
| 2026-04-06 12:00 |
03:28:47.04 |
-32:20:22.9 |
HIP 16125 |
15.05 |
| 2026-04-07 00:00 |
03:28:51.13 |
-32:19:40.7 |
HIP 16125 |
15.60 |
| 2026-04-07 12:00 |
03:28:55.24 |
-32:18:58.8 |
HIP 16125 |
16.22 |
| 2026-04-08 00:00 |
03:28:59.38 |
-32:18:17.2 |
HIP 16125 |
16.89 |
| 2026-04-08 12:00 |
03:29:03.55 |
-32:17:35.9 |
HIP 16125 |
17.62 |
| 2026-04-09 00:00 |
03:29:07.73 |
-32:16:54.9 |
HIP 16125 |
18.39 |
| 2026-04-09 12:00 |
03:29:11.94 |
-32:16:14.2 |
HIP 16125 |
19.20 |
| 2026-04-10 00:00 |
03:29:16.18 |
-32:15:33.8 |
HIP 16125 |
20.04 |
| 2026-04-10 12:00 |
03:29:20.43 |
-32:14:53.7 |
HIP 16125 |
20.92 |
| 2026-04-11 00:00 |
03:29:24.71 |
-32:14:14.0 |
HIP 16125 |
21.82 |
| 2026-04-11 12:00 |
03:29:29.01 |
-32:13:34.5 |
HIP 16125 |
22.75 |
| 2026-04-12 00:00 |
03:29:33.33 |
-32:12:55.4 |
HIP 16125 |
23.70 |
| 2026-04-12 12:00 |
03:29:37.67 |
-32:12:16.6 |
HIP 16366 |
23.72 |
| 2026-04-13 00:00 |
03:29:42.04 |
-32:11:38.1 |
HIP 16366 |
23.64 |
| 2026-04-13 12:00 |
03:29:46.42 |
-32:11:00.0 |
HIP 16366 |
23.60 |
| 2026-04-14 00:00 |
03:29:50.83 |
-32:10:22.2 |
HIP 16366 |
23.61 |
| 2026-04-14 12:00 |
03:29:55.25 |
-32:09:44.7 |
HIP 16366 |
23.67 |
| 2026-04-15 00:00 |
03:29:59.70 |
-32:09:07.5 |
HIP 16366 |
23.77 |
| 2026-04-15 12:00 |
03:30:04.16 |
-32:08:30.7 |
HIP 16366 |
23.91 |
| 2026-04-16 00:00 |
03:30:08.64 |
-32:07:54.3 |
HIP 16366 |
24.11 |