C/2021 J1 (Maury-Attard)

Metadata

Parameter Value
Designation C/2021 J1 (Maury-Attard)
Type C
Perihelion (tp_cal, UTC) 2021-02-19T11:39:16.738560Z
Orbit solution date (soln_date, UTC) 2022-02-03T20:43:07Z
Obs used 106
NEO -
M1 17.100
K1 5.250
PC -
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2021-04-27.0000000
e 0.93438376
q (au) 1.740634
a (au) 26.527482
i (deg) 92.719322
Ω (om, deg) 88.320215
ω (w, deg) 147.329778
M (ma, deg) 0.479817

Magnitude

C/2021 J1 (Maury-Attard) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (16.232 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 16.232
n 2.000
gf 1.000
gb -0.512
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)
2026-06-01 00:00 06:02:44.29 -40:45:29.9 HIP 28631 23.95
2026-06-01 12:00 06:02:54.08 -40:44:38.9 HIP 28631 24.90
2026-06-02 00:00 06:03:03.90 -40:43:48.7 HIP 28631 25.97
2026-06-02 12:00 06:03:13.74 -40:42:59.4 HIP 28631 27.14
2026-06-03 00:00 06:03:23.60 -40:42:10.9 HIP 28631 28.39
2026-06-03 12:00 06:03:33.48 -40:41:23.2 HIP 28745 28.90
2026-06-04 00:00 06:03:43.38 -40:40:36.3 HIP 28745 29.22
2026-06-04 12:00 06:03:53.29 -40:39:50.3 HIP 28745 29.66
2026-06-05 00:00 06:04:03.23 -40:39:05.1 HIP 28745 30.21
2026-06-05 12:00 06:04:13.18 -40:38:20.7 HIP 28745 30.88
2026-06-06 00:00 06:04:23.14 -40:37:37.2 HIP 28745 31.64
2026-06-06 12:00 06:04:33.13 -40:36:54.5 HIP 28745 32.50
2026-06-07 00:00 06:04:43.13 -40:36:12.6 HIP 28745 33.45
2026-06-07 12:00 06:04:53.14 -40:35:31.6 HIP 28857 32.65
2026-06-08 00:00 06:05:03.17 -40:34:51.4 HIP 28857 31.63
2026-06-08 12:00 06:05:13.21 -40:34:12.0 HIP 28857 30.73
2026-06-09 00:00 06:05:23.27 -40:33:33.5 HIP 28857 29.95
2026-06-09 12:00 06:05:33.34 -40:32:55.8 HIP 28857 29.30
2026-06-10 00:00 06:05:43.42 -40:32:19.0 HIP 28857 28.79
2026-06-10 12:00 06:05:53.51 -40:31:43.0 HIP 28857 28.44
2026-06-11 00:00 06:06:03.62 -40:31:07.9 HIP 28857 28.23
2026-06-11 12:00 06:06:13.73 -40:30:33.6 HIP 28857 28.19
2026-06-12 00:00 06:06:23.86 -40:30:00.2 HIP 28857 28.30
2026-06-12 12:00 06:06:33.99 -40:29:27.6 HIP 28857 28.56
2026-06-13 00:00 06:06:44.14 -40:28:55.8 HIP 28857 28.98
2026-06-13 12:00 06:06:54.29 -40:28:24.9 HIP 28857 29.54
2026-06-14 00:00 06:07:04.45 -40:27:54.9 HIP 28857 30.24
2026-06-14 12:00 06:07:14.62 -40:27:25.7 HIP 28857 31.06
2026-06-15 00:00 06:07:24.79 -40:26:57.3 HIP 28857 32.00
2026-06-15 12:00 06:07:34.97 -40:26:29.8 HIP 29263 30.06
2026-06-16 00:00 06:07:45.15 -40:26:03.2 HIP 29263 28.08
2026-06-16 12:00 06:07:55.34 -40:25:37.4 HIP 29263 26.09
2026-06-17 00:00 06:08:05.53 -40:25:12.5 HIP 29263 24.11
2026-06-17 12:00 06:08:15.73 -40:24:48.4 HIP 29263 22.13
2026-06-18 00:00 06:08:25.92 -40:24:25.1 HIP 29263 20.15
2026-06-18 12:00 06:08:36.12 -40:24:02.7 HIP 29263 18.18
2026-06-19 00:00 06:08:46.32 -40:23:41.2 HIP 29263 16.20
2026-06-19 12:00 06:08:56.53 -40:23:20.5 HIP 29263 14.23
2026-06-20 00:00 06:09:06.73 -40:23:00.7 HIP 29263 12.26
2026-06-20 12:00 06:09:16.93 -40:22:41.7 HIP 29263 10.29
2026-06-21 00:00 06:09:27.13 -40:22:23.5 HIP 29263 8.33
2026-06-21 12:00 06:09:37.33 -40:22:06.2 HIP 29263 6.36
2026-06-22 00:00 06:09:47.53 -40:21:49.7 HIP 29263 4.40