P/2020 V4 (Rankin)

Metadata

Parameter Value
Designation P/2020 V4 (Rankin)
Type P
Perihelion (tp_cal, UTC) 2021-07-17T22:00:33.958080Z
Orbit solution date (soln_date, UTC) 2025-09-09T12:42:49Z
Obs used 619
NEO -
M1 6.900
K1 12.250
PC -
Discovery observation (MPC, UTC) 2020-11-15T08:54:34.099200Z
Discovery magnitude (MPC) 19.23 G
Discovery observatory (MPC) G96 · University of Arizona Mt. Lemmon Survey
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2021-07-15.0000000
e 0.44887531
q (au) 5.148536
a (au) 9.341871
i (deg) 14.243119
Ω (om, deg) 203.507931
ω (w, deg) 256.995659
M (ma, deg) 359.899307

Magnitude

P/2020 V4 (Rankin) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (3.987 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 3.987
n 6.000
gf 0.897
gb -0.891
k 1.000
δ90 4.953
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

Residuals (Piecewise)

$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$

Start (UTC) End (UTC) a b
2015-10-10 2019-11-02 -11.2590 +10.593
2019-11-02 2021-04-21 +31.2873 -22.459
2021-08-30 2023-03-21 +28.4984 -21.118
2023-03-21 2024-03-17 -8.3408 +7.841

log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)

Ephemeris

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-07-29 00:00 13:55:00.89 -08:27:04.0 HIP 67967 10.40
2026-07-29 12:00 13:55:05.90 -08:27:27.8 HIP 67967 9.90
2026-07-30 00:00 13:55:10.99 -08:27:52.1 HIP 67967 9.54
2026-07-30 12:00 13:55:16.17 -08:28:16.8 HIP 67967 9.36
2026-07-31 00:00 13:55:21.44 -08:28:42.0 HIP 67967 9.36
2026-07-31 12:00 13:55:26.79 -08:29:07.7 HIP 67967 9.57
2026-08-01 00:00 13:55:32.24 -08:29:33.8 HIP 67967 9.98
2026-08-01 12:00 13:55:37.77 -08:30:00.5 HIP 67967 10.57
2026-08-02 00:00 13:55:43.39 -08:30:27.6 HIP 67967 11.33
2026-08-02 12:00 13:55:49.09 -08:30:55.1 HIP 67967 12.23
2026-08-03 00:00 13:55:54.89 -08:31:23.2 HIP 67967 13.25
2026-08-03 12:00 13:56:00.76 -08:31:51.7 HIP 67967 14.37
2026-08-04 00:00 13:56:06.73 -08:32:20.6 HIP 67967 15.58
2026-08-04 12:00 13:56:12.78 -08:32:50.0 HIP 67967 16.87
2026-08-05 00:00 13:56:18.91 -08:33:19.9 HIP 67967 18.22
2026-08-05 12:00 13:56:25.14 -08:33:50.2 HIP 67967 19.62
2026-08-06 00:00 13:56:31.44 -08:34:20.9 HIP 67967 21.08
2026-08-06 12:00 13:56:37.83 -08:34:52.1 HIP 67967 22.58
2026-08-07 00:00 13:56:44.31 -08:35:23.8 HIP 67967 24.12
2026-08-07 12:00 13:56:50.86 -08:35:55.9 HIP 67967 25.70
2026-08-08 00:00 13:56:57.51 -08:36:28.4 HIP 67967 27.32
2026-08-08 12:00 13:57:04.23 -08:37:01.4 HIP 67967 28.97
2026-08-09 00:00 13:57:11.04 -08:37:34.7 HIP 68241 29.77
2026-08-09 12:00 13:57:17.93 -08:38:08.6 HIP 68241 28.44
2026-08-10 00:00 13:57:24.90 -08:38:42.8 HIP 68241 27.15
2026-08-10 12:00 13:57:31.96 -08:39:17.5 HIP 68241 25.91
2026-08-11 00:00 13:57:39.10 -08:39:52.6 HIP 68241 24.72
2026-08-11 12:00 13:57:46.31 -08:40:28.1 HIP 68241 23.61
2026-08-12 00:00 13:57:53.61 -08:41:04.0 HIP 68241 22.60
2026-08-12 12:00 13:58:00.99 -08:41:40.3 HIP 68241 21.69
2026-08-13 00:00 13:58:08.45 -08:42:17.1 HIP 68241 20.91
2026-08-13 12:00 13:58:15.99 -08:42:54.2 HIP 68241 20.28
2026-08-14 00:00 13:58:23.61 -08:43:31.7 HIP 68241 19.82
2026-08-14 12:00 13:58:31.31 -08:44:09.7 HIP 68241 19.56
2026-08-15 00:00 13:58:39.09 -08:44:48.0 HIP 68241 19.49
2026-08-15 12:00 13:58:46.94 -08:45:26.7 HIP 68241 19.64
2026-08-16 00:00 13:58:54.87 -08:46:05.8 HIP 68241 20.00
2026-08-16 12:00 13:59:02.88 -08:46:45.3 HIP 68241 20.57
2026-08-17 00:00 13:59:10.96 -08:47:25.2 HIP 68241 21.34
2026-08-17 12:00 13:59:19.13 -08:48:05.4 HIP 68241 22.29
2026-08-18 00:00 13:59:27.36 -08:48:46.0 HIP 68241 23.40
2026-08-18 12:00 13:59:35.67 -08:49:27.0 HIP 68241 24.67
2026-08-19 00:00 13:59:44.06 -08:50:08.3 HIP 68241 26.06