| 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 |
-0.998 |
| 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) |
| 2026-06-01 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 |
| 2026-06-02 12:00 |
13:34:34.70 |
-50:25:44.2 |
HIP 66268 |
4.20 |
| 2026-06-03 00:00 |
13:34:30.18 |
-50:25:03.3 |
HIP 66268 |
4.44 |
| 2026-06-03 12:00 |
13:34:25.70 |
-50:24:22.2 |
HIP 66268 |
4.86 |
| 2026-06-04 00:00 |
13:34:21.27 |
-50:23:41.0 |
HIP 66268 |
5.43 |
| 2026-06-04 12:00 |
13:34:16.88 |
-50:22:59.7 |
HIP 66268 |
6.10 |
| 2026-06-05 00:00 |
13:34:12.53 |
-50:22:18.3 |
HIP 66268 |
6.83 |
| 2026-06-05 12:00 |
13:34:08.23 |
-50:21:36.7 |
HIP 66268 |
7.62 |
| 2026-06-06 00:00 |
13:34:03.97 |
-50:20:55.1 |
HIP 66268 |
8.44 |
| 2026-06-06 12:00 |
13:33:59.77 |
-50:20:13.3 |
HIP 66268 |
9.28 |
| 2026-06-07 00:00 |
13:33:55.60 |
-50:19:31.4 |
HIP 66268 |
10.14 |
| 2026-06-07 12:00 |
13:33:51.48 |
-50:18:49.4 |
HIP 66268 |
11.01 |
| 2026-06-08 00:00 |
13:33:47.41 |
-50:18:07.3 |
HIP 66268 |
11.88 |
| 2026-06-08 12:00 |
13:33:43.39 |
-50:17:25.1 |
HIP 66268 |
12.77 |
| 2026-06-09 00:00 |
13:33:39.41 |
-50:16:42.8 |
HIP 66268 |
13.66 |
| 2026-06-09 12:00 |
13:33:35.48 |
-50:16:00.5 |
HIP 66268 |
14.55 |
| 2026-06-10 00:00 |
13:33:31.59 |
-50:15:18.0 |
HIP 66268 |
15.44 |
| 2026-06-10 12:00 |
13:33:27.76 |
-50:14:35.5 |
HIP 66268 |
16.33 |
| 2026-06-11 00:00 |
13:33:23.97 |
-50:13:52.8 |
HIP 66268 |
17.22 |
| 2026-06-11 12:00 |
13:33:20.23 |
-50:13:10.1 |
HIP 66268 |
18.10 |
| 2026-06-12 00:00 |
13:33:16.53 |
-50:12:27.4 |
HIP 66268 |
18.99 |
| 2026-06-12 12:00 |
13:33:12.89 |
-50:11:44.6 |
HIP 66268 |
19.88 |
| 2026-06-13 00:00 |
13:33:09.30 |
-50:11:01.7 |
HIP 66268 |
20.76 |
| 2026-06-13 12:00 |
13:33:05.75 |
-50:10:18.7 |
HIP 66268 |
21.64 |
| 2026-06-14 00:00 |
13:33:02.25 |
-50:09:35.7 |
HIP 66268 |
22.52 |
| 2026-06-14 12:00 |
13:32:58.81 |
-50:08:52.7 |
HIP 66242 |
23.14 |
| 2026-06-15 00:00 |
13:32:55.41 |
-50:08:09.6 |
HIP 66242 |
23.00 |
| 2026-06-15 12:00 |
13:32:52.06 |
-50:07:26.4 |
HIP 66242 |
22.90 |
| 2026-06-16 00:00 |
13:32:48.76 |
-50:06:43.2 |
HIP 66242 |
22.83 |
| 2026-06-16 12:00 |
13:32:45.52 |
-50:06:00.0 |
HIP 66242 |
22.78 |
| 2026-06-17 00:00 |
13:32:42.32 |
-50:05:16.8 |
HIP 66242 |
22.76 |
| 2026-06-17 12:00 |
13:32:39.17 |
-50:04:33.5 |
HIP 66242 |
22.77 |
| 2026-06-18 00:00 |
13:32:36.08 |
-50:03:50.2 |
HIP 66242 |
22.80 |
| 2026-06-18 12:00 |
13:32:33.03 |
-50:03:06.9 |
HIP 66242 |
22.87 |
| 2026-06-19 00:00 |
13:32:30.04 |
-50:02:23.6 |
HIP 66242 |
22.96 |
| 2026-06-19 12:00 |
13:32:27.10 |
-50:01:40.3 |
HIP 66242 |
23.07 |
| 2026-06-20 00:00 |
13:32:24.21 |
-50:00:57.0 |
HIP 66242 |
23.21 |
| 2026-06-20 12:00 |
13:32:21.37 |
-50:00:13.6 |
HIP 66242 |
23.37 |
| 2026-06-21 00:00 |
13:32:18.58 |
-49:59:30.3 |
HIP 66242 |
23.55 |
| 2026-06-21 12:00 |
13:32:15.85 |
-49:58:47.0 |
HIP 66242 |
23.75 |
| 2026-06-22 00:00 |
13:32:13.16 |
-49:58:03.6 |
HIP 66242 |
23.98 |