P/2020 V4 (Rankin)
| 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 · 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
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 |
4.956 |
| 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 |
2019-10-26 |
-11.4012 |
+10.731 |
| 2019-10-26 |
2021-04-21 |
+29.3728 |
-21.080 |
| 2021-08-30 |
2023-03-21 |
+28.4984 |
-21.118 |
| 2023-03-21 |
2024-03-17 |
-8.3402 |
+7.840 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
14:19:54.32 |
-12:04:54.4 |
HIP 69945 |
15.96 |
| 2026-02-03 12:00 |
14:19:56.93 |
-12:04:44.7 |
HIP 69945 |
16.59 |
| 2026-02-04 00:00 |
14:19:59.42 |
-12:04:34.4 |
HIP 69945 |
17.19 |
| 2026-02-04 12:00 |
14:20:01.81 |
-12:04:23.5 |
HIP 69945 |
17.77 |
| 2026-02-05 00:00 |
14:20:04.08 |
-12:04:12.0 |
HIP 69945 |
18.32 |
| 2026-02-05 12:00 |
14:20:06.24 |
-12:03:59.9 |
HIP 69945 |
18.84 |
| 2026-02-06 00:00 |
14:20:08.29 |
-12:03:47.2 |
HIP 69945 |
19.34 |
| 2026-02-06 12:00 |
14:20:10.22 |
-12:03:33.9 |
HIP 69945 |
19.82 |
| 2026-02-07 00:00 |
14:20:12.05 |
-12:03:20.1 |
HIP 69945 |
20.26 |
| 2026-02-07 12:00 |
14:20:13.76 |
-12:03:05.6 |
HIP 69945 |
20.69 |
| 2026-02-08 00:00 |
14:20:15.36 |
-12:02:50.5 |
HIP 69945 |
21.09 |
| 2026-02-08 12:00 |
14:20:16.84 |
-12:02:34.9 |
HIP 69945 |
21.47 |
| 2026-02-09 00:00 |
14:20:18.22 |
-12:02:18.6 |
HIP 69945 |
21.82 |
| 2026-02-09 12:00 |
14:20:19.48 |
-12:02:01.8 |
HIP 69945 |
22.15 |
| 2026-02-10 00:00 |
14:20:20.62 |
-12:01:44.3 |
HIP 69945 |
22.45 |
| 2026-02-10 12:00 |
14:20:21.66 |
-12:01:26.3 |
HIP 69945 |
22.73 |
| 2026-02-11 00:00 |
14:20:22.58 |
-12:01:07.6 |
HIP 69945 |
22.99 |
| 2026-02-11 12:00 |
14:20:23.39 |
-12:00:48.4 |
HIP 69945 |
23.23 |
| 2026-02-12 00:00 |
14:20:24.08 |
-12:00:28.6 |
HIP 69945 |
23.44 |
| 2026-02-12 12:00 |
14:20:24.66 |
-12:00:08.2 |
HIP 69945 |
23.63 |
| 2026-02-13 00:00 |
14:20:25.13 |
-11:59:47.2 |
HIP 69945 |
23.80 |
| 2026-02-13 12:00 |
14:20:25.49 |
-11:59:25.6 |
HIP 69945 |
23.95 |
| 2026-02-14 00:00 |
14:20:25.73 |
-11:59:03.4 |
HIP 69945 |
24.08 |
| 2026-02-14 12:00 |
14:20:25.86 |
-11:58:40.6 |
HIP 69945 |
24.19 |
| 2026-02-15 00:00 |
14:20:25.87 |
-11:58:17.3 |
HIP 69945 |
24.28 |
| 2026-02-15 12:00 |
14:20:25.77 |
-11:57:53.3 |
HIP 69945 |
24.35 |
| 2026-02-16 00:00 |
14:20:25.56 |
-11:57:28.8 |
HIP 69945 |
24.40 |
| 2026-02-16 12:00 |
14:20:25.24 |
-11:57:03.7 |
HIP 69945 |
24.44 |
| 2026-02-17 00:00 |
14:20:24.81 |
-11:56:38.0 |
HIP 69945 |
24.46 |
| 2026-02-17 12:00 |
14:20:24.26 |
-11:56:11.7 |
HIP 69945 |
24.46 |
| 2026-02-18 00:00 |
14:20:23.60 |
-11:55:44.8 |
HIP 69945 |
24.45 |
| 2026-02-18 12:00 |
14:20:22.82 |
-11:55:17.4 |
HIP 69945 |
24.43 |
| 2026-02-19 00:00 |
14:20:21.94 |
-11:54:49.3 |
HIP 69945 |
24.39 |
| 2026-02-19 12:00 |
14:20:20.94 |
-11:54:20.8 |
HIP 69945 |
24.35 |
| 2026-02-20 00:00 |
14:20:19.83 |
-11:53:51.6 |
HIP 69945 |
24.29 |
| 2026-02-20 12:00 |
14:20:18.61 |
-11:53:21.8 |
HIP 69945 |
24.23 |
| 2026-02-21 00:00 |
14:20:17.28 |
-11:52:51.5 |
HIP 69945 |
24.16 |
| 2026-02-21 12:00 |
14:20:15.84 |
-11:52:20.7 |
HIP 69945 |
24.09 |
| 2026-02-22 00:00 |
14:20:14.29 |
-11:51:49.2 |
HIP 69945 |
24.01 |
| 2026-02-22 12:00 |
14:20:12.63 |
-11:51:17.2 |
HIP 69945 |
23.94 |
| 2026-02-23 00:00 |
14:20:10.85 |
-11:50:44.7 |
HIP 69945 |
23.86 |
| 2026-02-23 12:00 |
14:20:08.97 |
-11:50:11.6 |
HIP 69945 |
23.79 |
| 2026-02-24 00:00 |
14:20:06.98 |
-11:49:37.9 |
HIP 69945 |
23.72 |