| 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) |
| 2026-09-20 00:00 |
03:44:33.26 |
-33:49:11.3 |
HIP 17429 |
15.64 |
| 2026-09-20 12:00 |
03:44:30.78 |
-33:49:59.5 |
HIP 17429 |
14.69 |
| 2026-09-21 00:00 |
03:44:28.27 |
-33:50:47.6 |
HIP 17429 |
13.75 |
| 2026-09-21 12:00 |
03:44:25.72 |
-33:51:35.5 |
HIP 17429 |
12.81 |
| 2026-09-22 00:00 |
03:44:23.12 |
-33:52:23.2 |
HIP 17429 |
11.88 |
| 2026-09-22 12:00 |
03:44:20.49 |
-33:53:10.8 |
HIP 17429 |
10.94 |
| 2026-09-23 00:00 |
03:44:17.82 |
-33:53:58.2 |
HIP 17429 |
10.01 |
| 2026-09-23 12:00 |
03:44:15.11 |
-33:54:45.4 |
HIP 17429 |
9.10 |
| 2026-09-24 00:00 |
03:44:12.36 |
-33:55:32.5 |
HIP 17429 |
8.19 |
| 2026-09-24 12:00 |
03:44:09.58 |
-33:56:19.4 |
HIP 17429 |
7.30 |
| 2026-09-25 00:00 |
03:44:06.75 |
-33:57:06.0 |
HIP 17429 |
6.44 |
| 2026-09-25 12:00 |
03:44:03.89 |
-33:57:52.5 |
HIP 17429 |
5.61 |
| 2026-09-26 00:00 |
03:44:00.98 |
-33:58:38.8 |
HIP 17429 |
4.85 |
| 2026-09-26 12:00 |
03:43:58.04 |
-33:59:24.9 |
HIP 17429 |
4.18 |
| 2026-09-27 00:00 |
03:43:55.07 |
-34:00:10.8 |
HIP 17429 |
3.66 |
| 2026-09-27 12:00 |
03:43:52.05 |
-34:00:56.5 |
HIP 17429 |
3.37 |
| 2026-09-28 00:00 |
03:43:49.00 |
-34:01:42.0 |
HIP 17429 |
3.36 |
| 2026-09-28 12:00 |
03:43:45.91 |
-34:02:27.3 |
HIP 17429 |
3.63 |
| 2026-09-29 00:00 |
03:43:42.78 |
-34:03:12.4 |
HIP 17429 |
4.14 |
| 2026-09-29 12:00 |
03:43:39.62 |
-34:03:57.2 |
HIP 17429 |
4.81 |
| 2026-09-30 00:00 |
03:43:36.42 |
-34:04:41.8 |
HIP 17429 |
5.58 |
| 2026-09-30 12:00 |
03:43:33.19 |
-34:05:26.2 |
HIP 17429 |
6.42 |
| 2026-10-01 00:00 |
03:43:29.91 |
-34:06:10.4 |
HIP 17429 |
7.31 |
| 2026-10-01 12:00 |
03:43:26.61 |
-34:06:54.3 |
HIP 17429 |
8.22 |
| 2026-10-02 00:00 |
03:43:23.26 |
-34:07:38.0 |
HIP 17429 |
9.16 |
| 2026-10-02 12:00 |
03:43:19.88 |
-34:08:21.4 |
HIP 17429 |
10.12 |
| 2026-10-03 00:00 |
03:43:16.47 |
-34:09:04.6 |
HIP 17429 |
11.09 |
| 2026-10-03 12:00 |
03:43:13.02 |
-34:09:47.5 |
HIP 17429 |
12.07 |
| 2026-10-04 00:00 |
03:43:09.54 |
-34:10:30.2 |
HIP 17429 |
13.06 |
| 2026-10-04 12:00 |
03:43:06.02 |
-34:11:12.6 |
HIP 17429 |
14.05 |
| 2026-10-05 00:00 |
03:43:02.47 |
-34:11:54.8 |
HIP 17429 |
15.05 |
| 2026-10-05 12:00 |
03:42:58.88 |
-34:12:36.7 |
HIP 17429 |
16.06 |
| 2026-10-06 00:00 |
03:42:55.26 |
-34:13:18.3 |
HIP 17295 |
15.29 |
| 2026-10-06 12:00 |
03:42:51.60 |
-34:13:59.7 |
HIP 17295 |
14.28 |
| 2026-10-07 00:00 |
03:42:47.92 |
-34:14:40.7 |
HIP 17295 |
13.27 |
| 2026-10-07 12:00 |
03:42:44.19 |
-34:15:21.5 |
HIP 17295 |
12.27 |
| 2026-10-08 00:00 |
03:42:40.44 |
-34:16:02.0 |
HIP 17295 |
11.27 |
| 2026-10-08 12:00 |
03:42:36.66 |
-34:16:42.2 |
HIP 17295 |
10.27 |
| 2026-10-09 00:00 |
03:42:32.84 |
-34:17:22.1 |
HIP 17295 |
9.29 |
| 2026-10-09 12:00 |
03:42:28.99 |
-34:18:01.7 |
HIP 17295 |
8.31 |
| 2026-10-10 00:00 |
03:42:25.11 |
-34:18:41.0 |
HIP 17295 |
7.36 |
| 2026-10-10 12:00 |
03:42:21.19 |
-34:19:20.0 |
HIP 17295 |
6.43 |
| 2026-10-11 00:00 |
03:42:17.25 |
-34:19:58.7 |
HIP 17295 |
5.54 |