C/2020 T5 (Lemmon)
| Parameter |
Value |
| Designation |
C/2020 T5 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-10-09T14:55:40.877760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:34:15Z |
| Obs used |
111 |
| NEO |
- |
| M1 |
16.200 |
| K1 |
10.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2020-10-05T02:23:25.872000Z |
| Discovery magnitude (MPC) |
20.59 G |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-10-12.0000000 |
| e |
0.99797054 |
| q (au) |
1.889011 |
| a (au) |
930.795662 |
| i (deg) |
66.603879 |
| Ω (om, deg) |
237.861698 |
| ω (w, deg) |
90.292383 |
| M (ma, deg) |
0.000083 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.381 + 4.112\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.381 |
| n |
4.112 |
| gf |
1.000 |
| gb |
-0.998 |
| k |
1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
05:25:47.15 |
-22:44:36.3 |
HIP 25395 |
2.51 |
| 2026-02-03 12:00 |
05:25:42.53 |
-22:43:42.9 |
HIP 25395 |
3.65 |
| 2026-02-04 00:00 |
05:25:37.97 |
-22:42:49.1 |
HIP 25395 |
4.91 |
| 2026-02-04 12:00 |
05:25:33.48 |
-22:41:54.9 |
HIP 25395 |
6.21 |
| 2026-02-05 00:00 |
05:25:29.05 |
-22:41:00.3 |
HIP 25395 |
7.52 |
| 2026-02-05 12:00 |
05:25:24.69 |
-22:40:05.2 |
HIP 25395 |
8.85 |
| 2026-02-06 00:00 |
05:25:20.39 |
-22:39:09.7 |
HIP 25395 |
10.17 |
| 2026-02-06 12:00 |
05:25:16.17 |
-22:38:13.7 |
HIP 25395 |
11.49 |
| 2026-02-07 00:00 |
05:25:12.00 |
-22:37:17.4 |
HIP 25395 |
12.81 |
| 2026-02-07 12:00 |
05:25:07.91 |
-22:36:20.7 |
HIP 25395 |
14.13 |
| 2026-02-08 00:00 |
05:25:03.88 |
-22:35:23.5 |
HIP 25395 |
15.44 |
| 2026-02-08 12:00 |
05:24:59.92 |
-22:34:26.0 |
HIP 25395 |
16.74 |
| 2026-02-09 00:00 |
05:24:56.03 |
-22:33:28.1 |
HIP 25395 |
18.04 |
| 2026-02-09 12:00 |
05:24:52.21 |
-22:32:29.8 |
HIP 25395 |
19.33 |
| 2026-02-10 00:00 |
05:24:48.45 |
-22:31:31.1 |
HIP 25395 |
20.62 |
| 2026-02-10 12:00 |
05:24:44.77 |
-22:30:32.1 |
HIP 25218 |
19.55 |
| 2026-02-11 00:00 |
05:24:41.15 |
-22:29:32.7 |
HIP 25218 |
18.29 |
| 2026-02-11 12:00 |
05:24:37.60 |
-22:28:33.0 |
HIP 25218 |
17.04 |
| 2026-02-12 00:00 |
05:24:34.12 |
-22:27:32.9 |
HIP 25218 |
15.80 |
| 2026-02-12 12:00 |
05:24:30.71 |
-22:26:32.5 |
HIP 25218 |
14.58 |
| 2026-02-13 00:00 |
05:24:27.38 |
-22:25:31.7 |
HIP 25218 |
13.39 |
| 2026-02-13 12:00 |
05:24:24.11 |
-22:24:30.7 |
HIP 25218 |
12.22 |
| 2026-02-14 00:00 |
05:24:20.91 |
-22:23:29.3 |
HIP 25218 |
11.08 |
| 2026-02-14 12:00 |
05:24:17.78 |
-22:22:27.6 |
HIP 25218 |
9.99 |
| 2026-02-15 00:00 |
05:24:14.73 |
-22:21:25.6 |
HIP 25218 |
8.95 |
| 2026-02-15 12:00 |
05:24:11.74 |
-22:20:23.3 |
HIP 25218 |
8.00 |
| 2026-02-16 00:00 |
05:24:08.83 |
-22:19:20.7 |
HIP 25218 |
7.15 |
| 2026-02-16 12:00 |
05:24:05.98 |
-22:18:17.8 |
HIP 25218 |
6.44 |
| 2026-02-17 00:00 |
05:24:03.21 |
-22:17:14.6 |
HIP 25218 |
5.93 |
| 2026-02-17 12:00 |
05:24:00.51 |
-22:16:11.2 |
HIP 25218 |
5.66 |
| 2026-02-18 00:00 |
05:23:57.88 |
-22:15:07.5 |
HIP 25218 |
5.67 |
| 2026-02-18 12:00 |
05:23:55.33 |
-22:14:03.5 |
HIP 25218 |
5.94 |
| 2026-02-19 00:00 |
05:23:52.84 |
-22:12:59.3 |
HIP 25218 |
6.46 |
| 2026-02-19 12:00 |
05:23:50.43 |
-22:11:54.9 |
HIP 25218 |
7.15 |
| 2026-02-20 00:00 |
05:23:48.09 |
-22:10:50.2 |
HIP 25218 |
7.98 |
| 2026-02-20 12:00 |
05:23:45.82 |
-22:09:45.3 |
HIP 25212 |
8.90 |
| 2026-02-21 00:00 |
05:23:43.63 |
-22:08:40.2 |
HIP 25212 |
9.86 |
| 2026-02-21 12:00 |
05:23:41.50 |
-22:07:34.9 |
HIP 25212 |
10.88 |
| 2026-02-22 00:00 |
05:23:39.45 |
-22:06:29.4 |
HIP 25212 |
11.94 |
| 2026-02-22 12:00 |
05:23:37.47 |
-22:05:23.6 |
HIP 25212 |
13.02 |
| 2026-02-23 00:00 |
05:23:35.57 |
-22:04:17.7 |
HIP 25212 |
14.12 |
| 2026-02-23 12:00 |
05:23:33.74 |
-22:03:11.6 |
HIP 25212 |
15.24 |
| 2026-02-24 00:00 |
05:23:31.97 |
-22:02:05.3 |
HIP 25212 |
16.36 |