| Parameter |
Value |
| Designation |
C/2021 L3 (Borisov) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2022-02-13T15:37:30.763200Z |
| Orbit solution date (soln_date, UTC) |
2024-04-20T20:42:18Z |
| Obs used |
215 |
| NEO |
- |
| M1 |
9.500 |
| K1 |
6.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2021-06-08T21:44:52.224000Z |
| Discovery magnitude (MPC) |
20.20 R |
| Discovery observatory (MPC) |
L51 · MARGO, Nauchnyi |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2022-03-04.0000000 |
| e |
1.00141430 |
| q (au) |
8.457762 |
| a (au) |
-5980.195992 |
| i (deg) |
78.580039 |
| Ω (om, deg) |
344.969335 |
| ω (w, deg) |
91.593885 |
| M (ma, deg) |
0.000039 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.235 + 2.109\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.235 |
| n |
2.109 |
| gf |
1.000 |
| gb |
-0.975 |
| k |
1.000 |
| δ90 |
9.999 |
| 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) |
| 2026-09-20 00:00 |
11:21:46.53 |
+21:34:15.1 |
HIP 55543 |
20.14 |
| 2026-09-20 12:00 |
11:21:54.29 |
+21:32:52.7 |
HIP 55543 |
17.99 |
| 2026-09-21 00:00 |
11:22:02.05 |
+21:31:30.7 |
HIP 55543 |
15.88 |
| 2026-09-21 12:00 |
11:22:09.79 |
+21:30:09.0 |
HIP 55543 |
13.83 |
| 2026-09-22 00:00 |
11:22:17.51 |
+21:28:47.7 |
HIP 55543 |
11.86 |
| 2026-09-22 12:00 |
11:22:25.23 |
+21:27:26.8 |
HIP 55543 |
10.01 |
| 2026-09-23 00:00 |
11:22:32.93 |
+21:26:06.2 |
HIP 55543 |
8.37 |
| 2026-09-23 12:00 |
11:22:40.61 |
+21:24:46.0 |
HIP 55543 |
7.08 |
| 2026-09-24 00:00 |
11:22:48.28 |
+21:23:26.1 |
HIP 55543 |
6.33 |
| 2026-09-24 12:00 |
11:22:55.93 |
+21:22:06.7 |
HIP 55543 |
6.33 |
| 2026-09-25 00:00 |
11:23:03.57 |
+21:20:47.6 |
HIP 55543 |
7.06 |
| 2026-09-25 12:00 |
11:23:11.20 |
+21:19:28.9 |
HIP 55543 |
8.33 |
| 2026-09-26 00:00 |
11:23:18.80 |
+21:18:10.6 |
HIP 55543 |
9.93 |
| 2026-09-26 12:00 |
11:23:26.39 |
+21:16:52.6 |
HIP 55543 |
11.73 |
| 2026-09-27 00:00 |
11:23:33.96 |
+21:15:35.0 |
HIP 55543 |
13.63 |
| 2026-09-27 12:00 |
11:23:41.51 |
+21:14:17.8 |
HIP 55543 |
15.61 |
| 2026-09-28 00:00 |
11:23:49.05 |
+21:13:01.0 |
HIP 55543 |
17.63 |
| 2026-09-28 12:00 |
11:23:56.56 |
+21:11:44.6 |
HIP 55543 |
19.67 |
| 2026-09-29 00:00 |
11:24:04.06 |
+21:10:28.6 |
HIP 55543 |
21.73 |
| 2026-09-29 12:00 |
11:24:11.53 |
+21:09:13.0 |
HIP 55543 |
23.81 |
| 2026-09-30 00:00 |
11:24:18.99 |
+21:07:57.7 |
HIP 55543 |
25.88 |
| 2026-09-30 12:00 |
11:24:26.43 |
+21:06:42.9 |
HIP 55543 |
27.97 |
| 2026-10-01 00:00 |
11:24:33.84 |
+21:05:28.4 |
HIP 55677 |
28.22 |
| 2026-10-01 12:00 |
11:24:41.23 |
+21:04:14.4 |
HIP 55677 |
27.12 |
| 2026-10-02 00:00 |
11:24:48.60 |
+21:03:00.8 |
HIP 55677 |
26.14 |
| 2026-10-02 12:00 |
11:24:55.95 |
+21:01:47.5 |
HIP 55677 |
25.32 |
| 2026-10-03 00:00 |
11:25:03.27 |
+21:00:34.7 |
HIP 55677 |
24.65 |
| 2026-10-03 12:00 |
11:25:10.58 |
+20:59:22.3 |
HIP 55677 |
24.14 |
| 2026-10-04 00:00 |
11:25:17.85 |
+20:58:10.2 |
HIP 55677 |
23.82 |
| 2026-10-04 12:00 |
11:25:25.11 |
+20:56:58.6 |
HIP 55677 |
23.68 |
| 2026-10-05 00:00 |
11:25:32.33 |
+20:55:47.5 |
HIP 55677 |
23.72 |
| 2026-10-05 12:00 |
11:25:39.54 |
+20:54:36.7 |
HIP 55677 |
23.94 |
| 2026-10-06 00:00 |
11:25:46.71 |
+20:53:26.4 |
HIP 55823 |
24.27 |
| 2026-10-06 12:00 |
11:25:53.86 |
+20:52:16.4 |
HIP 55823 |
22.57 |
| 2026-10-07 00:00 |
11:26:00.98 |
+20:51:06.9 |
HIP 55823 |
20.94 |
| 2026-10-07 12:00 |
11:26:08.08 |
+20:49:57.9 |
HIP 55823 |
19.39 |
| 2026-10-08 00:00 |
11:26:15.14 |
+20:48:49.2 |
HIP 55823 |
17.95 |
| 2026-10-08 12:00 |
11:26:22.18 |
+20:47:41.0 |
HIP 55823 |
16.63 |
| 2026-10-09 00:00 |
11:26:29.19 |
+20:46:33.3 |
HIP 55823 |
15.46 |
| 2026-10-09 12:00 |
11:26:36.17 |
+20:45:25.9 |
HIP 55823 |
14.49 |
| 2026-10-10 00:00 |
11:26:43.12 |
+20:44:19.0 |
HIP 55823 |
13.73 |
| 2026-10-10 12:00 |
11:26:50.03 |
+20:43:12.6 |
HIP 55823 |
13.23 |
| 2026-10-11 00:00 |
11:26:56.92 |
+20:42:06.6 |
HIP 55823 |
13.02 |