| Parameter |
Value |
| Designation |
C/2023 F2 (SOHO) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-03-21T03:59:23.654400Z |
| Orbit solution date (soln_date, UTC) |
2025-02-28T10:03:47Z |
| Obs used |
82 |
| NEO |
- |
| M1 |
20.800 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2023-03-21T00:06:17.568000Z |
| Discovery magnitude (MPC) |
4.90 V |
| Discovery observatory (MPC) |
249 · SOHO |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-03-21.0000000 |
| e |
1.01189649 |
| q (au) |
0.034240 |
| a (au) |
-2.878182 |
| i (deg) |
72.567452 |
| Ω (om, deg) |
71.422437 |
| ω (w, deg) |
57.765098 |
| M (ma, deg) |
-0.033557 |
Magnitude
Scatter + Global Linear
$$
M_a = (20.000 + 3.781\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
20.000 |
| n |
3.781 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
0.800 |
| δ90 |
1.000 |
| 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 |
18:34:59.01 |
-68:06:28.6 |
HIP 90986 |
19.97 |
| 2026-03-26 12:00 |
18:34:59.63 |
-68:07:49.4 |
HIP 90986 |
21.23 |
| 2026-03-27 00:00 |
18:35:00.07 |
-68:09:10.4 |
HIP 90986 |
22.49 |
| 2026-03-27 12:00 |
18:35:00.35 |
-68:10:31.4 |
HIP 90815 |
23.50 |
| 2026-03-28 00:00 |
18:35:00.45 |
-68:11:52.4 |
HIP 90815 |
24.28 |
| 2026-03-28 12:00 |
18:35:00.38 |
-68:13:13.6 |
HIP 90815 |
25.11 |
| 2026-03-29 00:00 |
18:35:00.14 |
-68:14:34.7 |
HIP 90815 |
25.96 |
| 2026-03-29 12:00 |
18:34:59.72 |
-68:15:55.9 |
HIP 90815 |
26.85 |
| 2026-03-30 00:00 |
18:34:59.13 |
-68:17:17.2 |
HIP 90815 |
27.76 |
| 2026-03-30 12:00 |
18:34:58.36 |
-68:18:38.4 |
HIP 90815 |
28.69 |
| 2026-03-31 00:00 |
18:34:57.42 |
-68:19:59.7 |
HIP 90815 |
29.65 |
| 2026-03-31 12:00 |
18:34:56.31 |
-68:21:21.0 |
HIP 90815 |
30.63 |
| 2026-04-01 00:00 |
18:34:55.01 |
-68:22:42.3 |
HIP 90815 |
31.63 |
| 2026-04-01 12:00 |
18:34:53.55 |
-68:24:03.7 |
HIP 90815 |
32.65 |
| 2026-04-02 00:00 |
18:34:51.90 |
-68:25:25.0 |
HIP 90815 |
33.68 |
| 2026-04-02 12:00 |
18:34:50.08 |
-68:26:46.3 |
HIP 90815 |
34.72 |
| 2026-04-03 00:00 |
18:34:48.08 |
-68:28:07.6 |
HIP 90675 |
33.91 |
| 2026-04-03 12:00 |
18:34:45.90 |
-68:29:28.9 |
HIP 90675 |
32.88 |
| 2026-04-04 00:00 |
18:34:43.54 |
-68:30:50.2 |
HIP 90675 |
31.86 |
| 2026-04-04 12:00 |
18:34:41.01 |
-68:32:11.4 |
HIP 90675 |
30.86 |
| 2026-04-05 00:00 |
18:34:38.30 |
-68:33:32.6 |
HIP 90675 |
29.88 |
| 2026-04-05 12:00 |
18:34:35.40 |
-68:34:53.8 |
HIP 90675 |
28.91 |
| 2026-04-06 00:00 |
18:34:32.33 |
-68:36:14.9 |
HIP 90675 |
27.97 |
| 2026-04-06 12:00 |
18:34:29.08 |
-68:37:36.0 |
HIP 90675 |
27.05 |
| 2026-04-07 00:00 |
18:34:25.65 |
-68:38:56.9 |
HIP 90675 |
26.16 |
| 2026-04-07 12:00 |
18:34:22.03 |
-68:40:17.9 |
HIP 90675 |
25.30 |
| 2026-04-08 00:00 |
18:34:18.24 |
-68:41:38.7 |
HIP 90675 |
24.47 |
| 2026-04-08 12:00 |
18:34:14.26 |
-68:42:59.5 |
HIP 90675 |
23.68 |
| 2026-04-09 00:00 |
18:34:10.11 |
-68:44:20.2 |
HIP 90675 |
22.93 |
| 2026-04-09 12:00 |
18:34:05.77 |
-68:45:40.7 |
HIP 90675 |
22.23 |
| 2026-04-10 00:00 |
18:34:01.25 |
-68:47:01.2 |
HIP 90675 |
21.59 |
| 2026-04-10 12:00 |
18:33:56.54 |
-68:48:21.6 |
HIP 90675 |
21.00 |
| 2026-04-11 00:00 |
18:33:51.66 |
-68:49:41.9 |
HIP 90675 |
20.47 |
| 2026-04-11 12:00 |
18:33:46.59 |
-68:51:02.0 |
HIP 90675 |
20.02 |
| 2026-04-12 00:00 |
18:33:41.34 |
-68:52:22.0 |
HIP 91221 |
19.58 |
| 2026-04-12 12:00 |
18:33:35.90 |
-68:53:41.9 |
HIP 91221 |
19.14 |
| 2026-04-13 00:00 |
18:33:30.28 |
-68:55:01.6 |
HIP 91221 |
18.82 |
| 2026-04-13 12:00 |
18:33:24.48 |
-68:56:21.2 |
HIP 90672 |
18.59 |
| 2026-04-14 00:00 |
18:33:18.49 |
-68:57:40.6 |
HIP 90672 |
18.38 |
| 2026-04-14 12:00 |
18:33:12.32 |
-68:58:59.8 |
HIP 90672 |
18.26 |
| 2026-04-15 00:00 |
18:33:05.97 |
-69:00:18.9 |
HIP 90672 |
18.23 |
| 2026-04-15 12:00 |
18:32:59.43 |
-69:01:37.8 |
HIP 90672 |
18.31 |
| 2026-04-16 00:00 |
18:32:52.71 |
-69:02:56.5 |
HIP 90672 |
18.48 |