| Parameter |
Value |
| Designation |
C/2015 F3 (SWAN) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-03-09T08:31:54.042240Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:09Z |
| Obs used |
316 |
| NEO |
- |
| M1 |
14.200 |
| K1 |
8.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-04-16.0000000 |
| e |
0.99638676 |
| q (au) |
0.834438 |
| a (au) |
230.939218 |
| i (deg) |
73.386412 |
| Ω (om, deg) |
31.639644 |
| ω (w, deg) |
57.566073 |
| M (ma, deg) |
0.010572 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.649 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.649 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.999 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2015-03-24 |
2015-05-30 |
+6.9369 |
-1.877 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
13:38:26.05 |
-50:52:07.2 |
HIP 66442 |
11.41 |
| 2026-05-12 12:00 |
13:38:19.96 |
-50:51:35.4 |
HIP 66442 |
10.38 |
| 2026-05-13 00:00 |
13:38:13.91 |
-50:51:03.4 |
HIP 66442 |
9.37 |
| 2026-05-13 12:00 |
13:38:07.88 |
-50:50:31.0 |
HIP 66442 |
8.38 |
| 2026-05-14 00:00 |
13:38:01.88 |
-50:49:58.3 |
HIP 66442 |
7.42 |
| 2026-05-14 12:00 |
13:37:55.90 |
-50:49:25.4 |
HIP 66442 |
6.52 |
| 2026-05-15 00:00 |
13:37:49.96 |
-50:48:52.2 |
HIP 66442 |
5.69 |
| 2026-05-15 12:00 |
13:37:44.05 |
-50:48:18.7 |
HIP 66442 |
4.96 |
| 2026-05-16 00:00 |
13:37:38.16 |
-50:47:45.0 |
HIP 66442 |
4.39 |
| 2026-05-16 12:00 |
13:37:32.31 |
-50:47:11.0 |
HIP 66442 |
4.04 |
| 2026-05-17 00:00 |
13:37:26.49 |
-50:46:36.7 |
HIP 66442 |
3.98 |
| 2026-05-17 12:00 |
13:37:20.70 |
-50:46:02.2 |
HIP 66442 |
4.21 |
| 2026-05-18 00:00 |
13:37:14.95 |
-50:45:27.4 |
HIP 66442 |
4.68 |
| 2026-05-18 12:00 |
13:37:09.22 |
-50:44:52.4 |
HIP 66442 |
5.34 |
| 2026-05-19 00:00 |
13:37:03.53 |
-50:44:17.2 |
HIP 66442 |
6.12 |
| 2026-05-19 12:00 |
13:36:57.88 |
-50:43:41.7 |
HIP 66442 |
6.98 |
| 2026-05-20 00:00 |
13:36:52.25 |
-50:43:05.9 |
HIP 66442 |
7.90 |
| 2026-05-20 12:00 |
13:36:46.67 |
-50:42:29.9 |
HIP 66442 |
8.85 |
| 2026-05-21 00:00 |
13:36:41.11 |
-50:41:53.7 |
HIP 66442 |
9.82 |
| 2026-05-21 12:00 |
13:36:35.59 |
-50:41:17.3 |
HIP 66442 |
10.81 |
| 2026-05-22 00:00 |
13:36:30.11 |
-50:40:40.6 |
HIP 66442 |
11.82 |
| 2026-05-22 12:00 |
13:36:24.67 |
-50:40:03.7 |
HIP 66442 |
12.83 |
| 2026-05-23 00:00 |
13:36:19.26 |
-50:39:26.6 |
HIP 66442 |
13.85 |
| 2026-05-23 12:00 |
13:36:13.88 |
-50:38:49.3 |
HIP 66442 |
14.87 |
| 2026-05-24 00:00 |
13:36:08.55 |
-50:38:11.8 |
HIP 66259 |
15.57 |
| 2026-05-24 12:00 |
13:36:03.25 |
-50:37:34.1 |
HIP 66259 |
15.31 |
| 2026-05-25 00:00 |
13:35:57.99 |
-50:36:56.2 |
HIP 66259 |
15.13 |
| 2026-05-25 12:00 |
13:35:52.77 |
-50:36:18.0 |
HIP 66259 |
15.02 |
| 2026-05-26 00:00 |
13:35:47.59 |
-50:35:39.7 |
HIP 66259 |
14.99 |
| 2026-05-26 12:00 |
13:35:42.44 |
-50:35:01.2 |
HIP 66268 |
14.12 |
| 2026-05-27 00:00 |
13:35:37.34 |
-50:34:22.5 |
HIP 66268 |
13.14 |
| 2026-05-27 12:00 |
13:35:32.27 |
-50:33:43.7 |
HIP 66268 |
12.18 |
| 2026-05-28 00:00 |
13:35:27.25 |
-50:33:04.6 |
HIP 66268 |
11.23 |
| 2026-05-28 12:00 |
13:35:22.27 |
-50:32:25.4 |
HIP 66268 |
10.29 |
| 2026-05-29 00:00 |
13:35:17.32 |
-50:31:46.0 |
HIP 66268 |
9.38 |
| 2026-05-29 12:00 |
13:35:12.42 |
-50:31:06.4 |
HIP 66268 |
8.49 |
| 2026-05-30 00:00 |
13:35:07.56 |
-50:30:26.7 |
HIP 66268 |
7.63 |
| 2026-05-30 12:00 |
13:35:02.74 |
-50:29:46.8 |
HIP 66268 |
6.81 |
| 2026-05-31 00:00 |
13:34:57.96 |
-50:29:06.7 |
HIP 66268 |
6.05 |
| 2026-05-31 12:00 |
13:34:53.22 |
-50:28:26.5 |
HIP 66268 |
5.37 |
| 2026-06-01 00:00 |
13:34:48.53 |
-50:27:46.2 |
HIP 66268 |
4.81 |
| 2026-06-01 12:00 |
13:34:43.87 |
-50:27:05.7 |
HIP 66268 |
4.40 |
| 2026-06-02 00:00 |
13:34:39.26 |
-50:26:25.0 |
HIP 66268 |
4.18 |