C/2024 D1 (Lemmon)

Metadata

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 · University of Arizona 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

C/2024 D1 (Lemmon) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (3.802 + 4.676\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 3.802
n 4.676
gf 0.997
gb -1.000
k 1.000
δ90 9.995
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)
2026-06-01 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
2026-06-02 12:00 06:18:43.88 +65:58:09.5 HIP 29737 20.71
2026-06-03 00:00 06:18:58.59 +65:57:14.7 HIP 30125 21.38
2026-06-03 12:00 06:19:13.40 +65:56:20.9 HIP 30125 19.99
2026-06-04 00:00 06:19:28.29 +65:55:28.1 HIP 30125 18.67
2026-06-04 12:00 06:19:43.27 +65:54:36.3 HIP 30125 17.44
2026-06-05 00:00 06:19:58.34 +65:53:45.6 HIP 30125 16.33
2026-06-05 12:00 06:20:13.49 +65:52:55.9 HIP 30125 15.36
2026-06-06 00:00 06:20:28.72 +65:52:07.2 HIP 30125 14.55
2026-06-06 12:00 06:20:44.04 +65:51:19.5 HIP 30125 13.94
2026-06-07 00:00 06:20:59.44 +65:50:32.9 HIP 30125 13.55
2026-06-07 12:00 06:21:14.91 +65:49:47.3 HIP 30125 13.40
2026-06-08 00:00 06:21:30.46 +65:49:02.8 HIP 30125 13.51
2026-06-08 12:00 06:21:46.08 +65:48:19.2 HIP 30125 13.86
2026-06-09 00:00 06:22:01.78 +65:47:36.8 HIP 30125 14.43
2026-06-09 12:00 06:22:17.56 +65:46:55.3 HIP 30125 15.21
2026-06-10 00:00 06:22:33.40 +65:46:14.9 HIP 30125 16.16
2026-06-10 12:00 06:22:49.31 +65:45:35.5 HIP 30125 17.25
2026-06-11 00:00 06:23:05.29 +65:44:57.2 HIP 30125 18.46
2026-06-11 12:00 06:23:21.33 +65:44:19.9 HIP 30125 19.77
2026-06-12 00:00 06:23:37.44 +65:43:43.7 HIP 30596 21.01
2026-06-12 12:00 06:23:53.61 +65:43:08.5 HIP 30596 19.51
2026-06-13 00:00 06:24:09.84 +65:42:34.3 HIP 30596 18.07
2026-06-13 12:00 06:24:26.14 +65:42:01.2 HIP 30596 16.71
2026-06-14 00:00 06:24:42.49 +65:41:29.2 HIP 30596 15.44
2026-06-14 12:00 06:24:58.89 +65:40:58.2 HIP 30596 14.29
2026-06-15 00:00 06:25:15.35 +65:40:28.2 HIP 30596 13.30
2026-06-15 12:00 06:25:31.86 +65:39:59.4 HIP 30596 12.50
2026-06-16 00:00 06:25:48.42 +65:39:31.5 HIP 30596 11.92
2026-06-16 12:00 06:26:05.03 +65:39:04.8 HIP 30596 11.62
2026-06-17 00:00 06:26:21.69 +65:38:39.1 HIP 30596 11.59
2026-06-17 12:00 06:26:38.40 +65:38:14.4 HIP 30596 11.86
2026-06-18 00:00 06:26:55.14 +65:37:50.8 HIP 30596 12.39
2026-06-18 12:00 06:27:11.93 +65:37:28.3 HIP 30596 13.16
2026-06-19 00:00 06:27:28.76 +65:37:06.8 HIP 30596 14.13
2026-06-19 12:00 06:27:45.63 +65:36:46.4 HIP 30596 15.26
2026-06-20 00:00 06:28:02.53 +65:36:27.1 HIP 30596 16.52
2026-06-20 12:00 06:28:19.47 +65:36:08.8 HIP 30596 17.88
2026-06-21 00:00 06:28:36.45 +65:35:51.6 HIP 30596 19.32
2026-06-21 12:00 06:28:53.46 +65:35:35.5 HIP 30596 20.82
2026-06-22 00:00 06:29:10.49 +65:35:20.4 HIP 30596 22.38