| Parameter |
Value |
| Designation |
C/2015 C2 (SWAN) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-03-04T13:33:59.673600Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:06Z |
| Obs used |
151 |
| NEO |
- |
| M1 |
12.700 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-04-26.0000000 |
| e |
0.99851030 |
| q (au) |
0.711377 |
| a (au) |
477.531702 |
| i (deg) |
94.501074 |
| Ω (om, deg) |
49.529700 |
| ω (w, deg) |
334.134062 |
| M (ma, deg) |
0.004952 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.217 + 3.643\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.217 |
| n |
3.643 |
| 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) |
| 2026-06-01 00:00 |
16:08:19.27 |
+25:32:20.2 |
HIP 79225 |
24.38 |
| 2026-06-01 12:00 |
16:08:14.45 |
+25:32:20.6 |
HIP 79225 |
25.46 |
| 2026-06-02 00:00 |
16:08:09.64 |
+25:32:20.5 |
HIP 79225 |
26.54 |
| 2026-06-02 12:00 |
16:08:04.83 |
+25:32:20.0 |
HIP 79225 |
27.62 |
| 2026-06-03 00:00 |
16:08:00.03 |
+25:32:19.1 |
HIP 79225 |
28.69 |
| 2026-06-03 12:00 |
16:07:55.24 |
+25:32:17.8 |
HIP 79225 |
29.77 |
| 2026-06-04 00:00 |
16:07:50.45 |
+25:32:16.0 |
HIP 79225 |
30.84 |
| 2026-06-04 12:00 |
16:07:45.67 |
+25:32:13.8 |
HIP 79225 |
31.91 |
| 2026-06-05 00:00 |
16:07:40.90 |
+25:32:11.3 |
HIP 79225 |
32.97 |
| 2026-06-05 12:00 |
16:07:36.14 |
+25:32:08.3 |
HIP 79225 |
34.04 |
| 2026-06-06 00:00 |
16:07:31.39 |
+25:32:04.9 |
HIP 79225 |
35.10 |
| 2026-06-06 12:00 |
16:07:26.64 |
+25:32:01.0 |
HIP 79225 |
36.17 |
| 2026-06-07 00:00 |
16:07:21.91 |
+25:31:56.8 |
HIP 79225 |
37.23 |
| 2026-06-07 12:00 |
16:07:17.19 |
+25:31:52.1 |
HIP 78994 |
37.43 |
| 2026-06-08 00:00 |
16:07:12.47 |
+25:31:47.0 |
HIP 78760 |
36.71 |
| 2026-06-08 12:00 |
16:07:07.77 |
+25:31:41.5 |
HIP 78760 |
35.73 |
| 2026-06-09 00:00 |
16:07:03.08 |
+25:31:35.6 |
HIP 78760 |
34.75 |
| 2026-06-09 12:00 |
16:06:58.40 |
+25:31:29.3 |
HIP 78760 |
33.78 |
| 2026-06-10 00:00 |
16:06:53.73 |
+25:31:22.5 |
HIP 78760 |
32.81 |
| 2026-06-10 12:00 |
16:06:49.07 |
+25:31:15.4 |
HIP 78760 |
31.85 |
| 2026-06-11 00:00 |
16:06:44.43 |
+25:31:07.8 |
HIP 78760 |
30.89 |
| 2026-06-11 12:00 |
16:06:39.79 |
+25:30:59.8 |
HIP 78760 |
29.94 |
| 2026-06-12 00:00 |
16:06:35.18 |
+25:30:51.4 |
HIP 78760 |
28.99 |
| 2026-06-12 12:00 |
16:06:30.57 |
+25:30:42.6 |
HIP 78760 |
28.05 |
| 2026-06-13 00:00 |
16:06:25.98 |
+25:30:33.4 |
HIP 78760 |
27.11 |
| 2026-06-13 12:00 |
16:06:21.40 |
+25:30:23.8 |
HIP 78760 |
26.19 |
| 2026-06-14 00:00 |
16:06:16.84 |
+25:30:13.7 |
HIP 78760 |
25.27 |
| 2026-06-14 12:00 |
16:06:12.29 |
+25:30:03.3 |
HIP 78760 |
24.36 |
| 2026-06-15 00:00 |
16:06:07.76 |
+25:29:52.4 |
HIP 78760 |
23.45 |
| 2026-06-15 12:00 |
16:06:03.25 |
+25:29:41.1 |
HIP 78760 |
22.56 |
| 2026-06-16 00:00 |
16:05:58.75 |
+25:29:29.4 |
HIP 78760 |
21.68 |
| 2026-06-16 12:00 |
16:05:54.27 |
+25:29:17.4 |
HIP 78760 |
20.81 |
| 2026-06-17 00:00 |
16:05:49.80 |
+25:29:04.9 |
HIP 78760 |
19.96 |
| 2026-06-17 12:00 |
16:05:45.35 |
+25:28:52.0 |
HIP 78760 |
19.11 |
| 2026-06-18 00:00 |
16:05:40.92 |
+25:28:38.7 |
HIP 78760 |
18.29 |
| 2026-06-18 12:00 |
16:05:36.51 |
+25:28:25.0 |
HIP 78760 |
17.48 |
| 2026-06-19 00:00 |
16:05:32.11 |
+25:28:10.9 |
HIP 78760 |
16.70 |
| 2026-06-19 12:00 |
16:05:27.74 |
+25:27:56.4 |
HIP 78760 |
15.93 |
| 2026-06-20 00:00 |
16:05:23.38 |
+25:27:41.5 |
HIP 78760 |
15.20 |
| 2026-06-20 12:00 |
16:05:19.04 |
+25:27:26.2 |
HIP 78760 |
14.49 |
| 2026-06-21 00:00 |
16:05:14.72 |
+25:27:10.6 |
HIP 78760 |
13.82 |
| 2026-06-21 12:00 |
16:05:10.43 |
+25:26:54.5 |
HIP 78760 |
13.19 |
| 2026-06-22 00:00 |
16:05:06.15 |
+25:26:38.0 |
HIP 78760 |
12.60 |