| Parameter |
Value |
| Designation |
C/2023 A2 (SWAN) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-01-20T09:20:12.062400Z |
| Orbit solution date (soln_date, UTC) |
2026-03-12T09:30:38Z |
| Obs used |
159 |
| NEO |
- |
| M1 |
12.800 |
| K1 |
20.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2023-01-06T00:00:00Z |
| Discovery magnitude (MPC) |
- |
| Discovery observatory (MPC) |
249 · SOHO |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-03-06.0000000 |
| e |
0.99829132 |
| q (au) |
0.947460 |
| a (au) |
554.499318 |
| i (deg) |
94.708355 |
| Ω (om, deg) |
94.471088 |
| ω (w, deg) |
142.583308 |
| M (ma, deg) |
0.003367 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.826 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.826 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-1.000 |
| k |
0.840 |
| 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) |
| 2026-03-26 00:00 |
06:04:58.31 |
-47:27:33.9 |
HIP 28768 |
4.89 |
| 2026-03-26 12:00 |
06:04:59.79 |
-47:24:45.5 |
HIP 28768 |
6.44 |
| 2026-03-27 00:00 |
06:05:01.39 |
-47:21:57.5 |
HIP 28768 |
8.66 |
| 2026-03-27 12:00 |
06:05:03.12 |
-47:19:09.7 |
HIP 28768 |
11.16 |
| 2026-03-28 00:00 |
06:05:04.98 |
-47:16:22.2 |
HIP 28768 |
13.79 |
| 2026-03-28 12:00 |
06:05:06.97 |
-47:13:35.1 |
HIP 28768 |
16.48 |
| 2026-03-29 00:00 |
06:05:09.09 |
-47:10:48.3 |
HIP 28845 |
13.96 |
| 2026-03-29 12:00 |
06:05:11.32 |
-47:08:01.9 |
HIP 28845 |
11.16 |
| 2026-03-30 00:00 |
06:05:13.69 |
-47:05:15.8 |
HIP 28845 |
8.36 |
| 2026-03-30 12:00 |
06:05:16.18 |
-47:02:30.1 |
HIP 28845 |
5.57 |
| 2026-03-31 00:00 |
06:05:18.79 |
-46:59:44.7 |
HIP 28845 |
2.79 |
| 2026-03-31 12:00 |
06:05:21.52 |
-46:56:59.8 |
HIP 28845 |
0.40 |
| 2026-04-01 00:00 |
06:05:24.38 |
-46:54:15.2 |
HIP 28845 |
2.84 |
| 2026-04-01 12:00 |
06:05:27.36 |
-46:51:31.0 |
HIP 28845 |
5.61 |
| 2026-04-02 00:00 |
06:05:30.46 |
-46:48:47.2 |
HIP 28845 |
8.39 |
| 2026-04-02 12:00 |
06:05:33.67 |
-46:46:03.8 |
HIP 28845 |
11.17 |
| 2026-04-03 00:00 |
06:05:37.01 |
-46:43:20.9 |
HIP 28845 |
13.94 |
| 2026-04-03 12:00 |
06:05:40.47 |
-46:40:38.4 |
HIP 28845 |
16.71 |
| 2026-04-04 00:00 |
06:05:44.04 |
-46:37:56.3 |
HIP 28845 |
19.48 |
| 2026-04-04 12:00 |
06:05:47.73 |
-46:35:14.7 |
HIP 28845 |
22.25 |
| 2026-04-05 00:00 |
06:05:51.53 |
-46:32:33.5 |
HIP 28987 |
23.41 |
| 2026-04-05 12:00 |
06:05:55.45 |
-46:29:52.8 |
HIP 28987 |
20.77 |
| 2026-04-06 00:00 |
06:05:59.49 |
-46:27:12.6 |
HIP 28987 |
18.16 |
| 2026-04-06 12:00 |
06:06:03.64 |
-46:24:32.9 |
HIP 28987 |
15.60 |
| 2026-04-07 00:00 |
06:06:07.90 |
-46:21:53.6 |
HIP 28987 |
13.11 |
| 2026-04-07 12:00 |
06:06:12.28 |
-46:19:14.9 |
HIP 28987 |
10.74 |
| 2026-04-08 00:00 |
06:06:16.77 |
-46:16:36.6 |
HIP 28987 |
8.59 |
| 2026-04-08 12:00 |
06:06:21.37 |
-46:13:58.9 |
HIP 28987 |
6.86 |
| 2026-04-09 00:00 |
06:06:26.08 |
-46:11:21.7 |
HIP 28987 |
5.92 |
| 2026-04-09 12:00 |
06:06:30.90 |
-46:08:45.1 |
HIP 28987 |
6.16 |
| 2026-04-10 00:00 |
06:06:35.82 |
-46:06:08.9 |
HIP 28987 |
7.45 |
| 2026-04-10 12:00 |
06:06:40.86 |
-46:03:33.4 |
HIP 28987 |
9.37 |
| 2026-04-11 00:00 |
06:06:46.01 |
-46:00:58.3 |
HIP 28987 |
11.61 |
| 2026-04-11 12:00 |
06:06:51.26 |
-45:58:23.9 |
HIP 28913 |
11.71 |
| 2026-04-12 00:00 |
06:06:56.62 |
-45:55:50.0 |
HIP 28913 |
10.44 |
| 2026-04-12 12:00 |
06:07:02.08 |
-45:53:16.7 |
HIP 28913 |
9.81 |
| 2026-04-13 00:00 |
06:07:07.65 |
-45:50:44.0 |
HIP 28913 |
9.94 |
| 2026-04-13 12:00 |
06:07:13.32 |
-45:48:11.9 |
HIP 28913 |
10.79 |
| 2026-04-14 00:00 |
06:07:19.10 |
-45:45:40.4 |
HIP 28913 |
12.22 |
| 2026-04-14 12:00 |
06:07:24.98 |
-45:43:09.5 |
HIP 28913 |
14.06 |
| 2026-04-15 00:00 |
06:07:30.96 |
-45:40:39.3 |
HIP 28913 |
16.15 |
| 2026-04-15 12:00 |
06:07:37.04 |
-45:38:09.6 |
HIP 28913 |
18.41 |
| 2026-04-16 00:00 |
06:07:43.22 |
-45:35:40.6 |
HIP 28913 |
20.79 |