| Parameter |
Value |
| Designation |
C/2024 J2 (Wierzchos) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2025-03-19T18:36:17.582400Z |
| Orbit solution date (soln_date, UTC) |
2026-03-11T21:13:02Z |
| Obs used |
451 |
| NEO |
- |
| M1 |
11.600 |
| K1 |
10.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2024-05-11T06:26:33.302400Z |
| Discovery magnitude (MPC) |
21.29 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2025-02-11.0000000 |
| e |
0.98760800 |
| q (au) |
1.810945 |
| a (au) |
146.138176 |
| i (deg) |
79.296967 |
| Ω (om, deg) |
189.059198 |
| ω (w, deg) |
143.153599 |
| M (ma, deg) |
359.979483 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.357 + 4.797\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.357 |
| n |
4.797 |
| gf |
0.995 |
| gb |
-0.712 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2024-03-12 |
2024-11-30 |
+3.8464 |
-1.845 |
| 2024-11-30 |
2025-02-05 |
-14.5390 |
+4.355 |
| 2025-06-26 |
2025-11-28 |
-5.8288 |
+2.402 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
05:50:59.70 |
-53:26:01.4 |
HIP 27599 |
3.46 |
| 2026-09-20 12:00 |
05:51:07.27 |
-53:31:09.2 |
HIP 27599 |
7.56 |
| 2026-09-21 00:00 |
05:51:14.58 |
-53:36:16.7 |
HIP 27671 |
3.72 |
| 2026-09-21 12:00 |
05:51:21.64 |
-53:41:24.0 |
HIP 27671 |
2.32 |
| 2026-09-22 00:00 |
05:51:28.43 |
-53:46:30.9 |
HIP 27671 |
7.18 |
| 2026-09-22 12:00 |
05:51:34.95 |
-53:51:37.5 |
HIP 27671 |
12.32 |
| 2026-09-23 00:00 |
05:51:41.21 |
-53:56:43.8 |
HIP 27671 |
17.49 |
| 2026-09-23 12:00 |
05:51:47.21 |
-54:01:49.8 |
HIP 27671 |
22.66 |
| 2026-09-24 00:00 |
05:51:52.94 |
-54:06:55.3 |
HIP 27671 |
27.81 |
| 2026-09-24 12:00 |
05:51:58.40 |
-54:12:00.5 |
HIP 27671 |
32.96 |
| 2026-09-25 00:00 |
05:52:03.59 |
-54:17:05.3 |
HIP 28091 |
37.65 |
| 2026-09-25 12:00 |
05:52:08.51 |
-54:22:09.6 |
HIP 28091 |
38.21 |
| 2026-09-26 00:00 |
05:52:13.16 |
-54:27:13.5 |
HIP 27515 |
35.57 |
| 2026-09-26 12:00 |
05:52:17.53 |
-54:32:17.0 |
HIP 27515 |
32.27 |
| 2026-09-27 00:00 |
05:52:21.63 |
-54:37:19.9 |
HIP 27515 |
29.46 |
| 2026-09-27 12:00 |
05:52:25.46 |
-54:42:22.4 |
HIP 27874 |
26.52 |
| 2026-09-28 00:00 |
05:52:29.01 |
-54:47:24.3 |
HIP 27874 |
21.95 |
| 2026-09-28 12:00 |
05:52:32.28 |
-54:52:25.7 |
HIP 27874 |
17.68 |
| 2026-09-29 00:00 |
05:52:35.27 |
-54:57:26.6 |
HIP 27874 |
13.97 |
| 2026-09-29 12:00 |
05:52:37.98 |
-55:02:26.8 |
HIP 27874 |
11.38 |
| 2026-09-30 00:00 |
05:52:40.41 |
-55:07:26.5 |
HIP 27874 |
10.73 |
| 2026-09-30 12:00 |
05:52:42.55 |
-55:12:25.5 |
HIP 27874 |
12.31 |
| 2026-10-01 00:00 |
05:52:44.42 |
-55:17:24.0 |
HIP 27874 |
15.44 |
| 2026-10-01 12:00 |
05:52:45.99 |
-55:22:21.7 |
HIP 27874 |
19.37 |
| 2026-10-02 00:00 |
05:52:47.28 |
-55:27:18.8 |
HIP 27977 |
23.21 |
| 2026-10-02 12:00 |
05:52:48.28 |
-55:32:15.2 |
HIP 27556 |
22.88 |
| 2026-10-03 00:00 |
05:52:49.00 |
-55:37:10.9 |
HIP 27923 |
19.70 |
| 2026-10-03 12:00 |
05:52:49.42 |
-55:42:05.8 |
HIP 27923 |
16.66 |
| 2026-10-04 00:00 |
05:52:49.55 |
-55:47:00.0 |
HIP 27923 |
14.72 |
| 2026-10-04 12:00 |
05:52:49.38 |
-55:51:53.4 |
HIP 27923 |
14.32 |
| 2026-10-05 00:00 |
05:52:48.92 |
-55:56:46.0 |
HIP 27757 |
15.54 |
| 2026-10-05 12:00 |
05:52:48.17 |
-56:01:37.8 |
HIP 27757 |
10.77 |
| 2026-10-06 00:00 |
05:52:47.12 |
-56:06:28.7 |
HIP 27757 |
6.14 |
| 2026-10-06 12:00 |
05:52:45.77 |
-56:11:18.8 |
HIP 27757 |
2.51 |
| 2026-10-07 00:00 |
05:52:44.13 |
-56:16:07.9 |
HIP 27757 |
4.63 |
| 2026-10-07 12:00 |
05:52:42.18 |
-56:20:56.2 |
HIP 27732 |
7.63 |
| 2026-10-08 00:00 |
05:52:39.94 |
-56:25:43.5 |
HIP 27732 |
3.69 |
| 2026-10-08 12:00 |
05:52:37.39 |
-56:30:29.8 |
HIP 27732 |
3.84 |
| 2026-10-09 00:00 |
05:52:34.54 |
-56:35:15.2 |
HIP 27732 |
7.83 |
| 2026-10-09 12:00 |
05:52:31.39 |
-56:39:59.5 |
HIP 27855 |
8.86 |
| 2026-10-10 00:00 |
05:52:27.94 |
-56:44:42.8 |
HIP 27855 |
10.34 |
| 2026-10-10 12:00 |
05:52:24.18 |
-56:49:25.1 |
HIP 27855 |
13.45 |
| 2026-10-11 00:00 |
05:52:20.11 |
-56:54:06.2 |
HIP 27737 |
15.26 |