| Parameter |
Value |
| Designation |
C/2023 X2 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2025-12-28T00:06:50.875200Z |
| Orbit solution date (soln_date, UTC) |
2026-07-28T14:12:17Z |
| Obs used |
604 |
| NEO |
- |
| M1 |
7.500 |
| K1 |
10.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2023-12-04T08:26:50.467200Z |
| Discovery magnitude (MPC) |
19.74 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2025-04-02.0000000 |
| e |
1.00032753 |
| q (au) |
5.089207 |
| a (au) |
-15538.191312 |
| i (deg) |
76.985839 |
| Ω (om, deg) |
66.305837 |
| ω (w, deg) |
64.744135 |
| M (ma, deg) |
-0.000137 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.873 + 5.071\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.873 |
| n |
5.071 |
| gf |
0.999 |
| gb |
-0.774 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
13:47:14.44 |
+70:24:32.1 |
HIP 67080 |
25.51 |
| 2026-07-29 12:00 |
13:47:44.39 |
+70:16:52.0 |
HIP 67080 |
33.52 |
| 2026-07-30 00:00 |
13:48:14.43 |
+70:09:12.0 |
HIP 67507 |
31.29 |
| 2026-07-30 12:00 |
13:48:44.56 |
+70:01:32.1 |
HIP 67507 |
23.22 |
| 2026-07-31 00:00 |
13:49:14.77 |
+69:53:52.4 |
HIP 67507 |
15.14 |
| 2026-07-31 12:00 |
13:49:45.06 |
+69:46:12.9 |
HIP 67507 |
7.09 |
| 2026-08-01 00:00 |
13:50:15.43 |
+69:38:33.5 |
HIP 67507 |
1.56 |
| 2026-08-01 12:00 |
13:50:45.88 |
+69:30:54.2 |
HIP 67507 |
9.27 |
| 2026-08-02 00:00 |
13:51:16.40 |
+69:23:15.1 |
HIP 67583 |
14.20 |
| 2026-08-02 12:00 |
13:51:47.01 |
+69:15:36.3 |
HIP 67583 |
7.99 |
| 2026-08-03 00:00 |
13:52:17.68 |
+69:07:57.6 |
HIP 67583 |
7.63 |
| 2026-08-03 12:00 |
13:52:48.44 |
+69:00:19.1 |
HIP 67583 |
13.60 |
| 2026-08-04 00:00 |
13:53:19.26 |
+68:52:40.8 |
HIP 67583 |
21.08 |
| 2026-08-04 12:00 |
13:53:50.16 |
+68:45:02.8 |
HIP 67826 |
28.92 |
| 2026-08-05 00:00 |
13:54:21.12 |
+68:37:25.0 |
HIP 67609 |
24.82 |
| 2026-08-05 12:00 |
13:54:52.16 |
+68:29:47.4 |
HIP 67609 |
22.60 |
| 2026-08-06 00:00 |
13:55:23.26 |
+68:22:10.1 |
HIP 68111 |
19.20 |
| 2026-08-06 12:00 |
13:55:54.43 |
+68:14:33.0 |
HIP 68111 |
11.06 |
| 2026-08-07 00:00 |
13:56:25.66 |
+68:06:56.3 |
HIP 68111 |
2.93 |
| 2026-08-07 12:00 |
13:56:56.96 |
+67:59:19.8 |
HIP 68111 |
5.26 |
| 2026-08-08 00:00 |
13:57:28.33 |
+67:51:43.7 |
HIP 68084 |
6.57 |
| 2026-08-08 12:00 |
13:57:59.76 |
+67:44:07.8 |
HIP 68084 |
13.68 |
| 2026-08-09 00:00 |
13:58:31.25 |
+67:36:32.3 |
HIP 68084 |
21.56 |
| 2026-08-09 12:00 |
13:59:02.80 |
+67:28:57.1 |
HIP 68377 |
27.06 |
| 2026-08-10 00:00 |
13:59:34.41 |
+67:21:22.2 |
HIP 68377 |
19.17 |
| 2026-08-10 12:00 |
14:00:06.08 |
+67:13:47.8 |
HIP 68377 |
11.69 |
| 2026-08-11 00:00 |
14:00:37.81 |
+67:06:13.7 |
HIP 68377 |
6.30 |
| 2026-08-11 12:00 |
14:01:09.60 |
+66:58:40.0 |
HIP 68377 |
8.76 |
| 2026-08-12 00:00 |
14:01:41.44 |
+66:51:06.7 |
HIP 68404 |
10.63 |
| 2026-08-12 12:00 |
14:02:13.34 |
+66:43:33.8 |
HIP 68404 |
12.17 |
| 2026-08-13 00:00 |
14:02:45.29 |
+66:36:01.3 |
HIP 68404 |
17.83 |
| 2026-08-13 12:00 |
14:03:17.30 |
+66:28:29.3 |
HIP 68812 |
12.10 |
| 2026-08-14 00:00 |
14:03:49.35 |
+66:20:57.7 |
HIP 68798 |
6.91 |
| 2026-08-14 12:00 |
14:04:21.46 |
+66:13:26.6 |
HIP 68798 |
7.83 |
| 2026-08-15 00:00 |
14:04:53.62 |
+66:05:55.9 |
HIP 68798 |
14.43 |
| 2026-08-15 12:00 |
14:05:25.82 |
+65:58:25.8 |
HIP 68798 |
22.10 |
| 2026-08-16 00:00 |
14:05:58.07 |
+65:50:56.2 |
HIP 69146 |
27.11 |
| 2026-08-16 12:00 |
14:06:30.37 |
+65:43:27.0 |
HIP 69146 |
20.11 |
| 2026-08-17 00:00 |
14:07:02.72 |
+65:35:58.4 |
HIP 69146 |
14.39 |
| 2026-08-17 12:00 |
14:07:35.10 |
+65:28:30.3 |
HIP 69146 |
11.96 |
| 2026-08-18 00:00 |
14:08:07.53 |
+65:21:02.8 |
HIP 69146 |
14.55 |
| 2026-08-18 12:00 |
14:08:40.00 |
+65:13:35.8 |
HIP 69167 |
16.33 |
| 2026-08-19 00:00 |
14:09:12.52 |
+65:06:09.4 |
HIP 69167 |
8.23 |