C/2015 F5 (SWAN-Xingming)
| 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
$$
M_a = (17.038 + 4.264\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.038 |
| n |
4.264 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
0.800 |
| δ90 |
3.167 |
| 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 |
-3.5160 |
-1.615 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
06:49:07.96 |
+19:57:42.7 |
HIP 32852 |
24.10 |
| 2026-02-03 12:00 |
06:49:02.68 |
+19:57:49.7 |
HIP 32852 |
25.33 |
| 2026-02-04 00:00 |
06:48:57.43 |
+19:57:56.8 |
HIP 32852 |
26.55 |
| 2026-02-04 12:00 |
06:48:52.22 |
+19:58:03.9 |
HIP 32852 |
27.77 |
| 2026-02-05 00:00 |
06:48:47.03 |
+19:58:10.9 |
HIP 32852 |
28.98 |
| 2026-02-05 12:00 |
06:48:41.88 |
+19:58:17.9 |
HIP 32852 |
30.19 |
| 2026-02-06 00:00 |
06:48:36.76 |
+19:58:25.0 |
HIP 32852 |
31.39 |
| 2026-02-06 12:00 |
06:48:31.67 |
+19:58:31.9 |
HIP 32852 |
32.58 |
| 2026-02-07 00:00 |
06:48:26.62 |
+19:58:38.9 |
HIP 32852 |
33.76 |
| 2026-02-07 12:00 |
06:48:21.60 |
+19:58:45.9 |
HIP 32852 |
34.94 |
| 2026-02-08 00:00 |
06:48:16.62 |
+19:58:52.8 |
HIP 32852 |
36.10 |
| 2026-02-08 12:00 |
06:48:11.67 |
+19:58:59.7 |
HIP 32676 |
36.44 |
| 2026-02-09 00:00 |
06:48:06.76 |
+19:59:06.6 |
HIP 32676 |
36.68 |
| 2026-02-09 12:00 |
06:48:01.88 |
+19:59:13.5 |
HIP 32676 |
36.96 |
| 2026-02-10 00:00 |
06:47:57.04 |
+19:59:20.3 |
HIP 32676 |
37.27 |
| 2026-02-10 12:00 |
06:47:52.23 |
+19:59:27.2 |
HIP 32676 |
37.60 |
| 2026-02-11 00:00 |
06:47:47.46 |
+19:59:34.0 |
HIP 32676 |
37.97 |
| 2026-02-11 12:00 |
06:47:42.73 |
+19:59:40.8 |
HIP 32676 |
38.36 |
| 2026-02-12 00:00 |
06:47:38.04 |
+19:59:47.5 |
HIP 32676 |
38.77 |
| 2026-02-12 12:00 |
06:47:33.38 |
+19:59:54.3 |
HIP 32676 |
39.21 |
| 2026-02-13 00:00 |
06:47:28.76 |
+20:00:01.0 |
HIP 32676 |
39.67 |
| 2026-02-13 12:00 |
06:47:24.19 |
+20:00:07.7 |
HIP 32302 |
38.93 |
| 2026-02-14 00:00 |
06:47:19.65 |
+20:00:14.4 |
HIP 32302 |
37.86 |
| 2026-02-14 12:00 |
06:47:15.14 |
+20:00:21.0 |
HIP 32302 |
36.81 |
| 2026-02-15 00:00 |
06:47:10.68 |
+20:00:27.6 |
HIP 32302 |
35.77 |
| 2026-02-15 12:00 |
06:47:06.26 |
+20:00:34.2 |
HIP 32302 |
34.73 |
| 2026-02-16 00:00 |
06:47:01.88 |
+20:00:40.8 |
HIP 32302 |
33.71 |
| 2026-02-16 12:00 |
06:46:57.54 |
+20:00:47.3 |
HIP 32302 |
32.69 |
| 2026-02-17 00:00 |
06:46:53.24 |
+20:00:53.8 |
HIP 32302 |
31.69 |
| 2026-02-17 12:00 |
06:46:48.98 |
+20:01:00.3 |
HIP 32302 |
30.70 |
| 2026-02-18 00:00 |
06:46:44.77 |
+20:01:06.7 |
HIP 32302 |
29.71 |
| 2026-02-18 12:00 |
06:46:40.59 |
+20:01:13.2 |
HIP 32302 |
28.74 |
| 2026-02-19 00:00 |
06:46:36.46 |
+20:01:19.5 |
HIP 32302 |
27.78 |
| 2026-02-19 12:00 |
06:46:32.37 |
+20:01:25.9 |
HIP 32302 |
26.83 |
| 2026-02-20 00:00 |
06:46:28.32 |
+20:01:32.2 |
HIP 32302 |
25.89 |
| 2026-02-20 12:00 |
06:46:24.32 |
+20:01:38.5 |
HIP 32302 |
24.97 |
| 2026-02-21 00:00 |
06:46:20.36 |
+20:01:44.8 |
HIP 32302 |
24.05 |
| 2026-02-21 12:00 |
06:46:16.44 |
+20:01:51.0 |
HIP 32302 |
23.15 |
| 2026-02-22 00:00 |
06:46:12.57 |
+20:01:57.2 |
HIP 32302 |
22.26 |
| 2026-02-22 12:00 |
06:46:08.74 |
+20:02:03.4 |
HIP 32302 |
21.38 |
| 2026-02-23 00:00 |
06:46:04.96 |
+20:02:09.5 |
HIP 32302 |
20.51 |
| 2026-02-23 12:00 |
06:46:01.22 |
+20:02:15.6 |
HIP 32302 |
19.66 |
| 2026-02-24 00:00 |
06:45:57.52 |
+20:02:21.7 |
HIP 32302 |
18.81 |