C/1981 M1 (Gonzalez)

Metadata

Parameter Value
Designation C/1981 M1 (Gonzalez)
Type C
Perihelion (tp_cal, UTC) 1981-03-25T15:42:23.296320Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:29:29Z
Obs used 20
NEO -
M1 -
K1 -
PC 0.030
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 1981-08-07.0000000
e 0.99935134
q (au) 2.333585
a (au) 3597.566450
i (deg) 107.144868
Ω (om, deg) 143.968785
ω (w, deg) 181.611922
M (ma, deg) 0.000614

Magnitude

C/1981 M1 (Gonzalez) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (8.178 + 2.822\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 8.178
n 2.822
gf 1.000
gb -0.998
k 1.000
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)
2026-03-26 00:00 09:40:05.62 -05:55:37.9 HIP 47539 35.19
2026-03-26 12:00 09:40:04.39 -05:55:25.2 HIP 47539 35.55
2026-03-27 00:00 09:40:03.16 -05:55:12.5 HIP 47539 35.90
2026-03-27 12:00 09:40:01.95 -05:54:59.7 HIP 47539 36.26
2026-03-28 00:00 09:40:00.75 -05:54:47.0 HIP 47539 36.61
2026-03-28 12:00 09:39:59.55 -05:54:34.2 HIP 47539 36.96
2026-03-29 00:00 09:39:58.37 -05:54:21.4 HIP 47539 37.31
2026-03-29 12:00 09:39:57.19 -05:54:08.7 HIP 47539 37.66
2026-03-30 00:00 09:39:56.03 -05:53:55.9 HIP 47539 38.00
2026-03-30 12:00 09:39:54.88 -05:53:43.1 HIP 47539 38.35
2026-03-31 00:00 09:39:53.74 -05:53:30.4 HIP 47539 38.69
2026-03-31 12:00 09:39:52.61 -05:53:17.6 HIP 47539 39.03
2026-04-01 00:00 09:39:51.49 -05:53:04.9 HIP 47539 39.37
2026-04-01 12:00 09:39:50.38 -05:52:52.1 HIP 47539 39.71
2026-04-02 00:00 09:39:49.28 -05:52:39.3 HIP 47539 40.05
2026-04-02 12:00 09:39:48.19 -05:52:26.6 HIP 47539 40.39
2026-04-03 00:00 09:39:47.11 -05:52:13.8 HIP 47539 40.72
2026-04-03 12:00 09:39:46.05 -05:52:01.1 HIP 47539 41.05
2026-04-04 00:00 09:39:44.99 -05:51:48.4 HIP 47539 41.38
2026-04-04 12:00 09:39:43.95 -05:51:35.7 HIP 47539 41.71
2026-04-05 00:00 09:39:42.92 -05:51:22.9 HIP 47539 42.04
2026-04-05 12:00 09:39:41.90 -05:51:10.2 HIP 47539 42.37
2026-04-06 00:00 09:39:40.89 -05:50:57.6 HIP 47539 42.69
2026-04-06 12:00 09:39:39.89 -05:50:44.9 HIP 47539 43.01
2026-04-07 00:00 09:39:38.91 -05:50:32.2 HIP 47539 43.33
2026-04-07 12:00 09:39:37.93 -05:50:19.6 HIP 47539 43.65
2026-04-08 00:00 09:39:36.97 -05:50:06.9 HIP 47539 43.96
2026-04-08 12:00 09:39:36.02 -05:49:54.3 HIP 47539 44.28
2026-04-09 00:00 09:39:35.08 -05:49:41.7 HIP 47539 44.59
2026-04-09 12:00 09:39:34.15 -05:49:29.1 HIP 47284 44.46
2026-04-10 00:00 09:39:33.24 -05:49:16.5 HIP 47284 44.17
2026-04-10 12:00 09:39:32.33 -05:49:04.0 HIP 47284 43.88
2026-04-11 00:00 09:39:31.44 -05:48:51.4 HIP 47284 43.60
2026-04-11 12:00 09:39:30.57 -05:48:38.9 HIP 47284 43.31
2026-04-12 00:00 09:39:29.70 -05:48:26.4 HIP 47284 43.03
2026-04-12 12:00 09:39:28.85 -05:48:13.9 HIP 47284 42.75
2026-04-13 00:00 09:39:28.00 -05:48:01.5 HIP 47284 42.47
2026-04-13 12:00 09:39:27.18 -05:47:49.1 HIP 47284 42.19
2026-04-14 00:00 09:39:26.36 -05:47:36.7 HIP 47284 41.92
2026-04-14 12:00 09:39:25.56 -05:47:24.3 HIP 47284 41.64
2026-04-15 00:00 09:39:24.76 -05:47:11.9 HIP 47284 41.37
2026-04-15 12:00 09:39:23.99 -05:46:59.6 HIP 47284 41.10
2026-04-16 00:00 09:39:23.22 -05:46:47.3 HIP 47284 40.83