| Parameter |
Value |
| Designation |
C/2015 F5 (SWAN-Xingming) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-03-28T02:23:27.029760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:09Z |
| Obs used |
209 |
| NEO |
Yes |
| M1 |
14.100 |
| K1 |
4.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-04-22.0000000 |
| e |
0.97774875 |
| q (au) |
0.346004 |
| a (au) |
15.549862 |
| i (deg) |
149.256648 |
| Ω (om, deg) |
287.739679 |
| ω (w, deg) |
13.393236 |
| M (ma, deg) |
0.400240 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.117 + 4.165\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.117 |
| n |
4.165 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2015-04-04 |
2015-06-07 |
-4.5612 |
-1.918 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
06:58:03.12 |
+19:51:16.4 |
HIP 33477 |
10.29 |
| 2026-07-29 12:00 |
06:58:07.79 |
+19:51:06.8 |
HIP 33477 |
10.97 |
| 2026-07-30 00:00 |
06:58:12.46 |
+19:50:57.3 |
HIP 33477 |
11.70 |
| 2026-07-30 12:00 |
06:58:17.10 |
+19:50:47.7 |
HIP 33477 |
12.49 |
| 2026-07-31 00:00 |
06:58:21.73 |
+19:50:38.1 |
HIP 33477 |
13.32 |
| 2026-07-31 12:00 |
06:58:26.34 |
+19:50:28.5 |
HIP 33477 |
14.18 |
| 2026-08-01 00:00 |
06:58:30.93 |
+19:50:18.9 |
HIP 33477 |
15.07 |
| 2026-08-01 12:00 |
06:58:35.50 |
+19:50:09.3 |
HIP 33477 |
15.98 |
| 2026-08-02 00:00 |
06:58:40.06 |
+19:49:59.7 |
HIP 33477 |
16.91 |
| 2026-08-02 12:00 |
06:58:44.60 |
+19:49:50.0 |
HIP 33477 |
17.85 |
| 2026-08-03 00:00 |
06:58:49.12 |
+19:49:40.4 |
HIP 33477 |
18.80 |
| 2026-08-03 12:00 |
06:58:53.61 |
+19:49:30.7 |
HIP 33477 |
19.76 |
| 2026-08-04 00:00 |
06:58:58.09 |
+19:49:21.0 |
HIP 33477 |
20.73 |
| 2026-08-04 12:00 |
06:59:02.55 |
+19:49:11.3 |
HIP 33477 |
21.70 |
| 2026-08-05 00:00 |
06:59:06.99 |
+19:49:01.6 |
HIP 33477 |
22.68 |
| 2026-08-05 12:00 |
06:59:11.41 |
+19:48:51.9 |
HIP 33477 |
23.65 |
| 2026-08-06 00:00 |
06:59:15.81 |
+19:48:42.2 |
HIP 33477 |
24.63 |
| 2026-08-06 12:00 |
06:59:20.19 |
+19:48:32.5 |
HIP 33477 |
25.61 |
| 2026-08-07 00:00 |
06:59:24.55 |
+19:48:22.8 |
HIP 33477 |
26.59 |
| 2026-08-07 12:00 |
06:59:28.88 |
+19:48:13.1 |
HIP 33477 |
27.57 |
| 2026-08-08 00:00 |
06:59:33.20 |
+19:48:03.4 |
HIP 33477 |
28.55 |
| 2026-08-08 12:00 |
06:59:37.49 |
+19:47:53.6 |
HIP 33477 |
29.52 |
| 2026-08-09 00:00 |
06:59:41.76 |
+19:47:43.9 |
HIP 33477 |
30.49 |
| 2026-08-09 12:00 |
06:59:46.00 |
+19:47:34.2 |
HIP 33477 |
31.47 |
| 2026-08-10 00:00 |
06:59:50.22 |
+19:47:24.4 |
HIP 33861 |
31.53 |
| 2026-08-10 12:00 |
06:59:54.42 |
+19:47:14.7 |
HIP 33861 |
30.76 |
| 2026-08-11 00:00 |
06:59:58.60 |
+19:47:04.9 |
HIP 33861 |
30.02 |
| 2026-08-11 12:00 |
07:00:02.75 |
+19:46:55.2 |
HIP 33861 |
29.29 |
| 2026-08-12 00:00 |
07:00:06.87 |
+19:46:45.5 |
HIP 33861 |
28.58 |
| 2026-08-12 12:00 |
07:00:10.97 |
+19:46:35.7 |
HIP 33861 |
27.90 |
| 2026-08-13 00:00 |
07:00:15.05 |
+19:46:26.0 |
HIP 33861 |
27.24 |
| 2026-08-13 12:00 |
07:00:19.10 |
+19:46:16.3 |
HIP 33861 |
26.60 |
| 2026-08-14 00:00 |
07:00:23.12 |
+19:46:06.6 |
HIP 33861 |
25.99 |
| 2026-08-14 12:00 |
07:00:27.12 |
+19:45:56.8 |
HIP 33861 |
25.40 |
| 2026-08-15 00:00 |
07:00:31.09 |
+19:45:47.1 |
HIP 33861 |
24.84 |
| 2026-08-15 12:00 |
07:00:35.04 |
+19:45:37.4 |
HIP 33861 |
24.31 |
| 2026-08-16 00:00 |
07:00:38.96 |
+19:45:27.7 |
HIP 33861 |
23.81 |
| 2026-08-16 12:00 |
07:00:42.85 |
+19:45:18.0 |
HIP 33861 |
23.34 |
| 2026-08-17 00:00 |
07:00:46.71 |
+19:45:08.3 |
HIP 33861 |
22.90 |
| 2026-08-17 12:00 |
07:00:50.54 |
+19:44:58.7 |
HIP 33861 |
22.49 |
| 2026-08-18 00:00 |
07:00:54.35 |
+19:44:49.0 |
HIP 33861 |
22.12 |
| 2026-08-18 12:00 |
07:00:58.13 |
+19:44:39.4 |
HIP 33861 |
21.78 |
| 2026-08-19 00:00 |
07:01:01.88 |
+19:44:29.7 |
HIP 33861 |
21.48 |