C/2021 QM45 (PANSTARRS)

Metadata

Parameter Value
Designation C/2021 QM45 (PANSTARRS)
Type C
Perihelion (tp_cal, UTC) 2022-08-13T10:26:49.989120Z
Orbit solution date (soln_date, UTC) 2023-03-20T19:42:38Z
Obs used 382
NEO -
M1 9.100
K1 15.250
PC -
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2022-08-10.0000000
e 0.99216612
q (au) 2.773251
a (au) 354.007155
i (deg) 22.822373
Ω (om, deg) 354.588581
ω (w, deg) 72.804814
M (ma, deg) 359.999492

Magnitude

C/2021 QM45 (PANSTARRS) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (7.914 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 7.914
n 6.000
gf 1.000
gb -0.501
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)
2026-09-20 00:00 12:22:30.88 -08:41:39.4 HIP 60315 10.52
2026-09-20 12:00 12:22:40.39 -08:42:48.9 HIP 60315 12.94
2026-09-21 00:00 12:22:49.90 -08:43:58.5 HIP 60315 15.43
2026-09-21 12:00 12:22:59.41 -08:45:08.2 HIP 60315 17.95
2026-09-22 00:00 12:23:08.93 -08:46:18.0 HIP 60315 20.51
2026-09-22 12:00 12:23:18.45 -08:47:28.0 HIP 60315 23.08
2026-09-23 00:00 12:23:27.98 -08:48:38.1 HIP 60315 25.66
2026-09-23 12:00 12:23:37.51 -08:49:48.3 HIP 60479 28.02
2026-09-24 00:00 12:23:47.04 -08:50:58.6 HIP 60479 28.92
2026-09-24 12:00 12:23:56.57 -08:52:09.0 HIP 60479 30.03
2026-09-25 00:00 12:24:06.11 -08:53:19.6 HIP 60479 31.32
2026-09-25 12:00 12:24:15.65 -08:54:30.2 HIP 60479 32.77
2026-09-26 00:00 12:24:25.18 -08:55:40.9 HIP 60479 34.37
2026-09-26 12:00 12:24:34.72 -08:56:51.8 HIP 60479 36.09
2026-09-27 00:00 12:24:44.26 -08:58:02.7 HIP 60745 34.27
2026-09-27 12:00 12:24:53.80 -08:59:13.7 HIP 60745 32.31
2026-09-28 00:00 12:25:03.34 -09:00:24.9 HIP 60745 30.46
2026-09-28 12:00 12:25:12.87 -09:01:36.1 HIP 60745 28.73
2026-09-29 00:00 12:25:22.41 -09:02:47.4 HIP 60745 27.15
2026-09-29 12:00 12:25:31.94 -09:03:58.8 HIP 60745 25.75
2026-09-30 00:00 12:25:41.47 -09:05:10.2 HIP 60745 24.55
2026-09-30 12:00 12:25:51.00 -09:06:21.8 HIP 60745 23.59
2026-10-01 00:00 12:26:00.52 -09:07:33.4 HIP 60745 22.89
2026-10-01 12:00 12:26:10.04 -09:08:45.1 HIP 60745 22.49
2026-10-02 00:00 12:26:19.56 -09:09:56.9 HIP 60745 22.39
2026-10-02 12:00 12:26:29.07 -09:11:08.8 HIP 60745 22.60
2026-10-03 00:00 12:26:38.57 -09:12:20.7 HIP 60745 23.12
2026-10-03 12:00 12:26:48.07 -09:13:32.7 HIP 60745 23.92
2026-10-04 00:00 12:26:57.57 -09:14:44.7 HIP 60745 24.97
2026-10-04 12:00 12:27:07.06 -09:15:56.8 HIP 60745 26.25
2026-10-05 00:00 12:27:16.54 -09:17:09.0 HIP 60745 27.72
2026-10-05 12:00 12:27:26.02 -09:18:21.2 HIP 60745 29.35
2026-10-06 00:00 12:27:35.48 -09:19:33.5 HIP 60745 31.12
2026-10-06 12:00 12:27:44.94 -09:20:45.8 HIP 60745 33.00
2026-10-07 00:00 12:27:54.39 -09:21:58.1 HIP 60745 34.98
2026-10-07 12:00 12:28:03.83 -09:23:10.5 HIP 60745 37.04
2026-10-08 00:00 12:28:13.26 -09:24:23.0 HIP 60745 39.17
2026-10-08 12:00 12:28:22.68 -09:25:35.5 HIP 61042 41.13
2026-10-09 00:00 12:28:32.09 -09:26:48.0 HIP 61042 38.54
2026-10-09 12:00 12:28:41.49 -09:28:00.5 HIP 61042 35.96
2026-10-10 00:00 12:28:50.88 -09:29:13.1 HIP 61042 33.38
2026-10-10 12:00 12:29:00.25 -09:30:25.7 HIP 61042 30.81
2026-10-11 00:00 12:29:09.62 -09:31:38.3 HIP 61042 28.25