C/2020 Q1 (Borisov)

Metadata

Parameter Value
Designation C/2020 Q1 (Borisov)
Type C
Perihelion (tp_cal, UTC) 2020-08-14T15:47:50.138880Z
Orbit solution date (soln_date, UTC) 2022-06-07T21:44:52Z
Obs used 280
NEO -
M1 11.700
K1 41.250
PC 0.030
Discovery observation (MPC, UTC) 2020-08-17T23:14:45.312000Z
Discovery magnitude (MPC) 17.80 R
Discovery observatory (MPC) L51 · MARGO, Nauchnyi
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2020-09-06.0000000
e 0.97788684
q (au) 1.314974
a (au) 59.465667
i (deg) 142.923814
Ω (om, deg) 52.379273
ω (w, deg) 9.884895
M (ma, deg) 0.048020

Magnitude

C/2020 Q1 (Borisov) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (15.650 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 15.650
n 6.000
gf 1.000
gb -1.000
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

Ephemeris

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-06-01 00:00 16:37:54.10 -08:49:09.6 HIP 81360 14.89
2026-06-01 12:00 16:37:45.80 -08:48:59.4 HIP 81360 12.99
2026-06-02 00:00 16:37:37.52 -08:48:49.3 HIP 81360 11.13
2026-06-02 12:00 16:37:29.23 -08:48:39.4 HIP 81360 9.37
2026-06-03 00:00 16:37:20.95 -08:48:29.8 HIP 81360 7.74
2026-06-03 12:00 16:37:12.67 -08:48:20.4 HIP 81360 6.36
2026-06-04 00:00 16:37:04.40 -08:48:11.1 HIP 81360 5.42
2026-06-04 12:00 16:36:56.13 -08:48:02.1 HIP 81360 5.16
2026-06-05 00:00 16:36:47.87 -08:47:53.4 HIP 81318 5.27
2026-06-05 12:00 16:36:39.62 -08:47:44.8 HIP 81318 4.04
2026-06-06 00:00 16:36:31.38 -08:47:36.5 HIP 81318 3.63
2026-06-06 12:00 16:36:23.14 -08:47:28.3 HIP 81318 4.29
2026-06-07 00:00 16:36:14.91 -08:47:20.4 HIP 81318 5.64
2026-06-07 12:00 16:36:06.69 -08:47:12.8 HIP 81318 7.32
2026-06-08 00:00 16:35:58.49 -08:47:05.3 HIP 81318 9.13
2026-06-08 12:00 16:35:50.29 -08:46:58.1 HIP 81318 11.02
2026-06-09 00:00 16:35:42.10 -08:46:51.1 HIP 81318 12.95
2026-06-09 12:00 16:35:33.93 -08:46:44.3 HIP 81318 14.90
2026-06-10 00:00 16:35:25.77 -08:46:37.8 HIP 81318 16.86
2026-06-10 12:00 16:35:17.62 -08:46:31.5 HIP 81318 18.83
2026-06-11 00:00 16:35:09.48 -08:46:25.4 HIP 81318 20.81
2026-06-11 12:00 16:35:01.37 -08:46:19.5 HIP 81318 22.78
2026-06-12 00:00 16:34:53.26 -08:46:13.9 HIP 81318 24.76
2026-06-12 12:00 16:34:45.17 -08:46:08.5 HIP 81318 26.74
2026-06-13 00:00 16:34:37.10 -08:46:03.4 HIP 81318 28.71
2026-06-13 12:00 16:34:29.05 -08:45:58.5 HIP 81318 30.69
2026-06-14 00:00 16:34:21.01 -08:45:53.8 HIP 81318 32.66
2026-06-14 12:00 16:34:12.99 -08:45:49.3 HIP 81318 34.62
2026-06-15 00:00 16:34:04.99 -08:45:45.1 HIP 81318 36.59
2026-06-15 12:00 16:33:57.02 -08:45:41.2 HIP 81159 37.83
2026-06-16 00:00 16:33:49.06 -08:45:37.4 HIP 81159 38.29
2026-06-16 12:00 16:33:41.12 -08:45:34.0 HIP 81159 38.85
2026-06-17 00:00 16:33:33.21 -08:45:30.7 HIP 81159 39.50
2026-06-17 12:00 16:33:25.31 -08:45:27.7 HIP 81159 40.23
2026-06-18 00:00 16:33:17.44 -08:45:24.9 HIP 81159 41.05
2026-06-18 12:00 16:33:09.60 -08:45:22.4 HIP 80873 40.33
2026-06-19 00:00 16:33:01.78 -08:45:20.1 HIP 80873 38.70
2026-06-19 12:00 16:32:53.98 -08:45:18.1 HIP 80873 37.11
2026-06-20 00:00 16:32:46.21 -08:45:16.3 HIP 80873 35.55
2026-06-20 12:00 16:32:38.46 -08:45:14.7 HIP 80873 34.03
2026-06-21 00:00 16:32:30.75 -08:45:13.4 HIP 80873 32.56
2026-06-21 12:00 16:32:23.06 -08:45:12.3 HIP 80873 31.13
2026-06-22 00:00 16:32:15.39 -08:45:11.5 HIP 80873 29.76