C/2019 F1 (ATLAS-Africano)

Metadata

Parameter Value
Designation C/2019 F1 (ATLAS-Africano)
Type C
Perihelion (tp_cal, UTC) 2021-06-22T19:03:30.551040Z
Orbit solution date (soln_date, UTC) 2024-04-13T16:42:29Z
Obs used 1964
NEO -
M1 9.600
K1 5.500
PC -
Discovery observation (MPC, UTC) 2019-03-29T10:03:21.600000Z
Discovery magnitude (MPC) 18.40 G
Discovery observatory (MPC) G96 · Mt. Lemmon Survey
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2020-10-21.0000000
e 1.00348898
q (au) 3.595914
a (au) -1030.647736
i (deg) 54.175708
Ω (om, deg) 38.726260
ω (w, deg) 251.113825
M (ma, deg) -0.007292

Magnitude

C/2019 F1 (ATLAS-Africano) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (8.031 + 2.895\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 8.031
n 2.895
gf 0.914
gb -0.906
k 1.000
δ90 1.000
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

Residuals (Piecewise)

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

Start (UTC) End (UTC) a b
2019-02-08 2019-10-14 +8.8747 -7.840
2019-10-14 2020-05-26 -6.5457 +4.593
2020-05-26 2021-06-18 -3.0290 +1.838
2021-06-27 2022-08-28 +0.5643 +0.081
2022-08-28 2022-12-25 -8.8752 +7.089
2022-12-25 2024-01-31 +9.9762 -7.455

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

Ephemeris

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-03-26 00:00 02:25:48.17 +21:10:48.0 HIP 11315 34.89
2026-03-26 12:00 02:25:55.89 +21:11:38.1 HIP 11315 34.21
2026-03-27 00:00 02:26:03.65 +21:12:28.5 HIP 11315 33.63
2026-03-27 12:00 02:26:11.44 +21:13:19.0 HIP 11315 33.15
2026-03-28 00:00 02:26:19.27 +21:14:09.8 HIP 11315 32.79
2026-03-28 12:00 02:26:27.12 +21:15:00.8 HIP 11315 32.55
2026-03-29 00:00 02:26:35.01 +21:15:52.0 HIP 11315 32.44
2026-03-29 12:00 02:26:42.93 +21:16:43.4 HIP 11559 31.22
2026-03-30 00:00 02:26:50.87 +21:17:35.0 HIP 11559 29.56
2026-03-30 12:00 02:26:58.85 +21:18:26.8 HIP 11559 27.95
2026-03-31 00:00 02:27:06.86 +21:19:18.8 HIP 11559 26.40
2026-03-31 12:00 02:27:14.89 +21:20:11.0 HIP 11559 24.91
2026-04-01 00:00 02:27:22.96 +21:21:03.5 HIP 11559 23.51
2026-04-01 12:00 02:27:31.05 +21:21:56.1 HIP 11559 22.21
2026-04-02 00:00 02:27:39.17 +21:22:48.9 HIP 11559 21.03
2026-04-02 12:00 02:27:47.31 +21:23:41.8 HIP 11559 19.99
2026-04-03 00:00 02:27:55.48 +21:24:35.0 HIP 11559 19.13
2026-04-03 12:00 02:28:03.68 +21:25:28.4 HIP 11559 18.47
2026-04-04 00:00 02:28:11.91 +21:26:21.9 HIP 11584 17.84
2026-04-04 12:00 02:28:20.16 +21:27:15.7 HIP 11584 15.74
2026-04-05 00:00 02:28:28.43 +21:28:09.6 HIP 11584 13.63
2026-04-05 12:00 02:28:36.73 +21:29:03.7 HIP 11584 11.53
2026-04-06 00:00 02:28:45.05 +21:29:57.9 HIP 11584 9.43
2026-04-06 12:00 02:28:53.40 +21:30:52.4 HIP 11584 7.34
2026-04-07 00:00 02:29:01.76 +21:31:47.0 HIP 11584 5.30
2026-04-07 12:00 02:29:10.16 +21:32:41.8 HIP 11584 3.39
2026-04-08 00:00 02:29:18.57 +21:33:36.8 HIP 11584 2.04
2026-04-08 12:00 02:29:27.00 +21:34:31.9 HIP 11584 2.48
2026-04-09 00:00 02:29:35.46 +21:35:27.2 HIP 11584 4.19
2026-04-09 12:00 02:29:43.94 +21:36:22.7 HIP 11584 6.20
2026-04-10 00:00 02:29:52.43 +21:37:18.3 HIP 11584 8.30
2026-04-10 12:00 02:30:00.95 +21:38:14.1 HIP 11584 10.44
2026-04-11 00:00 02:30:09.49 +21:39:10.1 HIP 11584 12.60
2026-04-11 12:00 02:30:18.04 +21:40:06.2 HIP 11584 14.77
2026-04-12 00:00 02:30:26.61 +21:41:02.4 HIP 11584 16.96
2026-04-12 12:00 02:30:35.20 +21:41:58.9 HIP 11584 19.15
2026-04-13 00:00 02:30:43.81 +21:42:55.4 HIP 11584 21.35
2026-04-13 12:00 02:30:52.44 +21:43:52.1 HIP 11728 22.60
2026-04-14 00:00 02:31:01.08 +21:44:49.0 HIP 11728 21.11
2026-04-14 12:00 02:31:09.74 +21:45:46.0 HIP 11728 19.75
2026-04-15 00:00 02:31:18.41 +21:46:43.2 HIP 11797 18.52
2026-04-15 12:00 02:31:27.10 +21:47:40.4 HIP 11797 16.48
2026-04-16 00:00 02:31:35.80 +21:48:37.9 HIP 11797 14.49