| 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) |
| 2026-07-29 00:00 |
05:17:41.77 |
-44:53:17.0 |
HIP 24765 |
15.13 |
| 2026-07-29 12:00 |
05:18:09.22 |
-44:57:25.5 |
HIP 24765 |
9.03 |
| 2026-07-30 00:00 |
05:18:36.55 |
-45:01:35.0 |
HIP 24765 |
3.92 |
| 2026-07-30 12:00 |
05:19:03.76 |
-45:05:45.8 |
HIP 24765 |
5.50 |
| 2026-07-31 00:00 |
05:19:30.84 |
-45:09:57.6 |
HIP 24765 |
11.21 |
| 2026-07-31 12:00 |
05:19:57.80 |
-45:14:10.6 |
HIP 25020 |
16.77 |
| 2026-08-01 00:00 |
05:20:24.63 |
-45:18:24.7 |
HIP 25020 |
11.01 |
| 2026-08-01 12:00 |
05:20:51.34 |
-45:22:39.9 |
HIP 25020 |
6.50 |
| 2026-08-02 00:00 |
05:21:17.92 |
-45:26:56.3 |
HIP 25020 |
6.62 |
| 2026-08-02 12:00 |
05:21:44.37 |
-45:31:13.7 |
HIP 25020 |
11.22 |
| 2026-08-03 00:00 |
05:22:10.69 |
-45:35:32.2 |
HIP 25122 |
11.97 |
| 2026-08-03 12:00 |
05:22:36.87 |
-45:39:51.8 |
HIP 25122 |
15.20 |
| 2026-08-04 00:00 |
05:23:02.93 |
-45:44:12.5 |
HIP 25122 |
19.97 |
| 2026-08-04 12:00 |
05:23:28.85 |
-45:48:34.3 |
HIP 25122 |
25.43 |
| 2026-08-05 00:00 |
05:23:54.64 |
-45:52:57.1 |
HIP 25080 |
30.01 |
| 2026-08-05 12:00 |
05:24:20.30 |
-45:57:21.0 |
HIP 25080 |
29.86 |
| 2026-08-06 00:00 |
05:24:45.81 |
-46:01:45.9 |
HIP 25506 |
26.30 |
| 2026-08-06 12:00 |
05:25:11.19 |
-46:06:11.9 |
HIP 25506 |
21.60 |
| 2026-08-07 00:00 |
05:25:36.43 |
-46:10:38.8 |
HIP 25506 |
17.92 |
| 2026-08-07 12:00 |
05:26:01.53 |
-46:15:06.9 |
HIP 25506 |
15.96 |
| 2026-08-08 00:00 |
05:26:26.49 |
-46:19:35.9 |
HIP 25506 |
16.35 |
| 2026-08-08 12:00 |
05:26:51.30 |
-46:24:05.9 |
HIP 25506 |
18.93 |
| 2026-08-09 00:00 |
05:27:15.97 |
-46:28:37.0 |
HIP 25506 |
22.97 |
| 2026-08-09 12:00 |
05:27:40.49 |
-46:33:09.0 |
HIP 25506 |
27.83 |
| 2026-08-10 00:00 |
05:28:04.87 |
-46:37:42.0 |
HIP 25746 |
32.34 |
| 2026-08-10 12:00 |
05:28:29.10 |
-46:42:16.0 |
HIP 25746 |
26.26 |
| 2026-08-11 00:00 |
05:28:53.17 |
-46:46:50.9 |
HIP 25746 |
20.22 |
| 2026-08-11 12:00 |
05:29:17.10 |
-46:51:26.7 |
HIP 25746 |
14.29 |
| 2026-08-12 00:00 |
05:29:40.87 |
-46:56:03.5 |
HIP 25746 |
8.66 |
| 2026-08-12 12:00 |
05:30:04.49 |
-47:00:41.3 |
HIP 25768 |
4.04 |
| 2026-08-13 00:00 |
05:30:27.95 |
-47:05:19.9 |
HIP 25768 |
3.22 |
| 2026-08-13 12:00 |
05:30:51.26 |
-47:09:59.4 |
HIP 25797 |
3.96 |
| 2026-08-14 00:00 |
05:31:14.41 |
-47:14:39.8 |
HIP 25797 |
7.77 |
| 2026-08-14 12:00 |
05:31:37.39 |
-47:19:21.1 |
HIP 25963 |
11.72 |
| 2026-08-15 00:00 |
05:32:00.22 |
-47:24:03.2 |
HIP 25963 |
5.64 |
| 2026-08-15 12:00 |
05:32:22.89 |
-47:28:46.2 |
HIP 25963 |
0.47 |
| 2026-08-16 00:00 |
05:32:45.39 |
-47:33:30.0 |
HIP 25963 |
6.51 |
| 2026-08-16 12:00 |
05:33:07.73 |
-47:38:14.6 |
HIP 26022 |
1.51 |
| 2026-08-17 00:00 |
05:33:29.90 |
-47:43:00.0 |
HIP 26022 |
4.89 |
| 2026-08-17 12:00 |
05:33:51.91 |
-47:47:46.3 |
HIP 26040 |
10.18 |
| 2026-08-18 00:00 |
05:34:13.75 |
-47:52:33.3 |
HIP 26040 |
10.04 |
| 2026-08-18 12:00 |
05:34:35.42 |
-47:57:21.1 |
HIP 26040 |
13.02 |
| 2026-08-19 00:00 |
05:34:56.92 |
-48:02:09.6 |
HIP 26040 |
17.60 |