| Parameter |
Value |
| Designation |
C/2024 D1 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2027-12-03T06:05:49.574400Z |
| Orbit solution date (soln_date, UTC) |
2026-03-07T11:42:49Z |
| Obs used |
66 |
| NEO |
- |
| M1 |
6.300 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2024-02-16T07:22:35.817600Z |
| Discovery magnitude (MPC) |
21.96 G |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2024-09-21.0000000 |
| e |
0.99896066 |
| q (au) |
6.696435 |
| a (au) |
6442.985621 |
| i (deg) |
132.456585 |
| Ω (om, deg) |
179.677442 |
| ω (w, deg) |
125.750357 |
| M (ma, deg) |
359.997774 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.875 + 2.854\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.875 |
| n |
2.854 |
| gf |
0.879 |
| gb |
-0.591 |
| k |
1.000 |
| δ90 |
1.001 |
| 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) |
| 2026-05-12 00:00 |
06:10:01.89 |
+66:53:23.8 |
HIP 29164 |
5.90 |
| 2026-05-12 12:00 |
06:10:10.95 |
+66:51:45.9 |
HIP 29164 |
7.47 |
| 2026-05-13 00:00 |
06:10:20.19 |
+66:50:08.9 |
HIP 29207 |
8.41 |
| 2026-05-13 12:00 |
06:10:29.60 |
+66:48:32.9 |
HIP 29207 |
7.72 |
| 2026-05-14 00:00 |
06:10:39.19 |
+66:46:57.8 |
HIP 29207 |
7.47 |
| 2026-05-14 12:00 |
06:10:48.95 |
+66:45:23.7 |
HIP 29207 |
7.69 |
| 2026-05-15 00:00 |
06:10:58.87 |
+66:43:50.6 |
HIP 29207 |
8.34 |
| 2026-05-15 12:00 |
06:11:08.96 |
+66:42:18.5 |
HIP 29207 |
9.33 |
| 2026-05-16 00:00 |
06:11:19.22 |
+66:40:47.4 |
HIP 29207 |
10.56 |
| 2026-05-16 12:00 |
06:11:29.63 |
+66:39:17.2 |
HIP 29207 |
11.96 |
| 2026-05-17 00:00 |
06:11:40.21 |
+66:37:48.1 |
HIP 29207 |
13.47 |
| 2026-05-17 12:00 |
06:11:50.94 |
+66:36:19.9 |
HIP 29207 |
15.05 |
| 2026-05-18 00:00 |
06:12:01.83 |
+66:34:52.7 |
HIP 29207 |
16.69 |
| 2026-05-18 12:00 |
06:12:12.87 |
+66:33:26.5 |
HIP 29207 |
18.37 |
| 2026-05-19 00:00 |
06:12:24.05 |
+66:32:01.3 |
HIP 29207 |
20.07 |
| 2026-05-19 12:00 |
06:12:35.39 |
+66:30:37.1 |
HIP 29207 |
21.79 |
| 2026-05-20 00:00 |
06:12:46.87 |
+66:29:13.9 |
HIP 29207 |
23.53 |
| 2026-05-20 12:00 |
06:12:58.49 |
+66:27:51.8 |
HIP 29720 |
24.70 |
| 2026-05-21 00:00 |
06:13:10.25 |
+66:26:30.6 |
HIP 29720 |
22.91 |
| 2026-05-21 12:00 |
06:13:22.15 |
+66:25:10.4 |
HIP 29720 |
21.12 |
| 2026-05-22 00:00 |
06:13:34.19 |
+66:23:51.2 |
HIP 29720 |
19.34 |
| 2026-05-22 12:00 |
06:13:46.36 |
+66:22:33.1 |
HIP 29720 |
17.56 |
| 2026-05-23 00:00 |
06:13:58.66 |
+66:21:15.9 |
HIP 29720 |
15.78 |
| 2026-05-23 12:00 |
06:14:11.09 |
+66:19:59.8 |
HIP 29720 |
14.01 |
| 2026-05-24 00:00 |
06:14:23.64 |
+66:18:44.6 |
HIP 29720 |
12.25 |
| 2026-05-24 12:00 |
06:14:36.33 |
+66:17:30.5 |
HIP 29720 |
10.50 |
| 2026-05-25 00:00 |
06:14:49.13 |
+66:16:17.4 |
HIP 29720 |
8.77 |
| 2026-05-25 12:00 |
06:15:02.06 |
+66:15:05.3 |
HIP 29720 |
7.07 |
| 2026-05-26 00:00 |
06:15:15.10 |
+66:13:54.2 |
HIP 29720 |
5.43 |
| 2026-05-26 12:00 |
06:15:28.26 |
+66:12:44.1 |
HIP 29720 |
3.91 |
| 2026-05-27 00:00 |
06:15:41.54 |
+66:11:35.0 |
HIP 29720 |
2.73 |
| 2026-05-27 12:00 |
06:15:54.93 |
+66:10:26.9 |
HIP 29720 |
2.44 |
| 2026-05-28 00:00 |
06:16:08.44 |
+66:09:19.9 |
HIP 29737 |
2.66 |
| 2026-05-28 12:00 |
06:16:22.05 |
+66:08:13.9 |
HIP 29737 |
3.75 |
| 2026-05-29 00:00 |
06:16:35.77 |
+66:07:08.9 |
HIP 29737 |
5.23 |
| 2026-05-29 12:00 |
06:16:49.60 |
+66:06:04.9 |
HIP 29737 |
6.85 |
| 2026-05-30 00:00 |
06:17:03.54 |
+66:05:01.9 |
HIP 29737 |
8.53 |
| 2026-05-30 12:00 |
06:17:17.57 |
+66:04:00.0 |
HIP 29737 |
10.24 |
| 2026-05-31 00:00 |
06:17:31.71 |
+66:02:59.0 |
HIP 29737 |
11.97 |
| 2026-05-31 12:00 |
06:17:45.95 |
+66:01:59.0 |
HIP 29737 |
13.71 |
| 2026-06-01 00:00 |
06:18:00.29 |
+66:01:00.1 |
HIP 29737 |
15.45 |
| 2026-06-01 12:00 |
06:18:14.72 |
+66:00:02.2 |
HIP 29737 |
17.20 |
| 2026-06-02 00:00 |
06:18:29.25 |
+65:59:05.3 |
HIP 29737 |
18.95 |