C/2012 E2 (SWAN)
| Parameter |
Value |
| Designation |
C/2012 E2 (SWAN) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2012-03-15T00:41:51.241920Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:04Z |
| Obs used |
43 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-03-13.0000000 |
| e |
1.00049131 |
| q (au) |
0.006962 |
| a (au) |
-14.169573 |
| i (deg) |
144.430741 |
| Ω (om, deg) |
6.576461 |
| ω (w, deg) |
82.412294 |
| M (ma, deg) |
-0.037494 |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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) |
| 2026-02-03 00:00 |
06:59:25.52 |
-13:10:32.2 |
HIP 33664 |
10.72 |
| 2026-02-03 12:00 |
06:59:22.77 |
-13:10:15.0 |
HIP 33664 |
10.63 |
| 2026-02-04 00:00 |
06:59:20.03 |
-13:09:57.7 |
HIP 33664 |
10.58 |
| 2026-02-04 12:00 |
06:59:17.31 |
-13:09:40.1 |
HIP 33664 |
10.58 |
| 2026-02-05 00:00 |
06:59:14.60 |
-13:09:22.4 |
HIP 33664 |
10.62 |
| 2026-02-05 12:00 |
06:59:11.91 |
-13:09:04.5 |
HIP 33664 |
10.71 |
| 2026-02-06 00:00 |
06:59:09.23 |
-13:08:46.4 |
HIP 33664 |
10.84 |
| 2026-02-06 12:00 |
06:59:06.57 |
-13:08:28.1 |
HIP 33664 |
11.01 |
| 2026-02-07 00:00 |
06:59:03.92 |
-13:08:09.7 |
HIP 33664 |
11.22 |
| 2026-02-07 12:00 |
06:59:01.30 |
-13:07:51.0 |
HIP 33664 |
11.47 |
| 2026-02-08 00:00 |
06:58:58.68 |
-13:07:32.3 |
HIP 33560 |
11.32 |
| 2026-02-08 12:00 |
06:58:56.09 |
-13:07:13.3 |
HIP 33560 |
10.65 |
| 2026-02-09 00:00 |
06:58:53.51 |
-13:06:54.2 |
HIP 33560 |
9.99 |
| 2026-02-09 12:00 |
06:58:50.95 |
-13:06:34.9 |
HIP 33560 |
9.34 |
| 2026-02-10 00:00 |
06:58:48.41 |
-13:06:15.4 |
HIP 33560 |
8.69 |
| 2026-02-10 12:00 |
06:58:45.89 |
-13:05:55.8 |
HIP 33560 |
8.06 |
| 2026-02-11 00:00 |
06:58:43.38 |
-13:05:36.0 |
HIP 33560 |
7.43 |
| 2026-02-11 12:00 |
06:58:40.89 |
-13:05:16.0 |
HIP 33560 |
6.82 |
| 2026-02-12 00:00 |
06:58:38.42 |
-13:04:55.9 |
HIP 33560 |
6.23 |
| 2026-02-12 12:00 |
06:58:35.97 |
-13:04:35.6 |
HIP 33560 |
5.65 |
| 2026-02-13 00:00 |
06:58:33.53 |
-13:04:15.2 |
HIP 33560 |
5.10 |
| 2026-02-13 12:00 |
06:58:31.12 |
-13:03:54.6 |
HIP 33560 |
4.59 |
| 2026-02-14 00:00 |
06:58:28.72 |
-13:03:33.9 |
HIP 33560 |
4.13 |
| 2026-02-14 12:00 |
06:58:26.35 |
-13:03:13.0 |
HIP 33560 |
3.73 |
| 2026-02-15 00:00 |
06:58:23.99 |
-13:02:52.0 |
HIP 33560 |
3.41 |
| 2026-02-15 12:00 |
06:58:21.65 |
-13:02:30.8 |
HIP 33560 |
3.21 |
| 2026-02-16 00:00 |
06:58:19.34 |
-13:02:09.4 |
HIP 33560 |
3.13 |
| 2026-02-16 12:00 |
06:58:17.04 |
-13:01:48.0 |
HIP 33560 |
3.18 |
| 2026-02-17 00:00 |
06:58:14.76 |
-13:01:26.4 |
HIP 33560 |
3.37 |
| 2026-02-17 12:00 |
06:58:12.51 |
-13:01:04.6 |
HIP 33560 |
3.65 |
| 2026-02-18 00:00 |
06:58:10.27 |
-13:00:42.7 |
HIP 33560 |
4.03 |
| 2026-02-18 12:00 |
06:58:08.05 |
-13:00:20.7 |
HIP 33560 |
4.46 |
| 2026-02-19 00:00 |
06:58:05.86 |
-12:59:58.5 |
HIP 33560 |
4.93 |
| 2026-02-19 12:00 |
06:58:03.69 |
-12:59:36.3 |
HIP 33560 |
5.44 |
| 2026-02-20 00:00 |
06:58:01.53 |
-12:59:13.8 |
HIP 33560 |
5.97 |
| 2026-02-20 12:00 |
06:57:59.40 |
-12:58:51.3 |
HIP 33560 |
6.51 |
| 2026-02-21 00:00 |
06:57:57.29 |
-12:58:28.6 |
HIP 33560 |
7.07 |
| 2026-02-21 12:00 |
06:57:55.21 |
-12:58:05.9 |
HIP 33560 |
7.63 |
| 2026-02-22 00:00 |
06:57:53.14 |
-12:57:42.9 |
HIP 33560 |
8.20 |
| 2026-02-22 12:00 |
06:57:51.10 |
-12:57:19.9 |
HIP 33560 |
8.78 |
| 2026-02-23 00:00 |
06:57:49.07 |
-12:56:56.8 |
HIP 33560 |
9.35 |
| 2026-02-23 12:00 |
06:57:47.08 |
-12:56:33.5 |
HIP 33560 |
9.93 |
| 2026-02-24 00:00 |
06:57:45.10 |
-12:56:10.2 |
HIP 33560 |
10.51 |