C/2025 O2 (MAPS)

Metadata

Parameter Value
Designation C/2025 O2 (MAPS)
Type C
Perihelion (tp_cal, UTC) 2025-05-23T16:42:19.152000Z
Orbit solution date (soln_date, UTC) 2025-09-22T13:42:18Z
Obs used 88
NEO -
M1 7.400
K1 27.000
PC -
Discovery observation (MPC, UTC) 2025-07-25T09:35:29.760000Z
Discovery magnitude (MPC) 18.80 G
Discovery observatory (MPC) W94 · MAPS, San Pedro de Atacama
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2025-08-14.0000000
e 0.99886564
q (au) 2.288532
a (au) 2017.460252
i (deg) 134.542008
Ω (om, deg) 332.313059
ω (w, deg) 280.240987
M (ma, deg) 0.000895

Magnitude

C/2025 O2 (MAPS) · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (11.254 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 11.254
n 6.000
gf 0.998
gb -0.500
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)
2026-07-29 00:00 21:34:21.35 -00:30:29.2 HIP 106385 32.15
2026-07-29 12:00 21:33:43.08 -00:31:02.0 HIP 106385 25.72
2026-07-30 00:00 21:33:04.77 -00:31:36.0 HIP 106324 18.73
2026-07-30 12:00 21:32:26.43 -00:32:11.0 HIP 106324 11.99
2026-07-31 00:00 21:31:48.06 -00:32:47.0 HIP 106324 10.98
2026-07-31 12:00 21:31:09.67 -00:33:24.2 HIP 106324 16.79
2026-08-01 00:00 21:30:31.26 -00:34:02.4 HIP 106324 25.07
2026-08-01 12:00 21:29:52.83 -00:34:41.6 HIP 105983 30.60
2026-08-02 00:00 21:29:14.39 -00:35:21.9 HIP 105983 21.48
2026-08-02 12:00 21:28:35.95 -00:36:03.2 HIP 105983 13.11
2026-08-03 00:00 21:27:57.50 -00:36:45.5 HIP 105983 8.29
2026-08-03 12:00 21:27:19.06 -00:37:28.8 HIP 105983 12.31
2026-08-04 00:00 21:26:40.62 -00:38:13.1 HIP 105983 20.50
2026-08-04 12:00 21:26:02.19 -00:38:58.4 HIP 105797 21.38
2026-08-05 00:00 21:25:23.77 -00:39:44.7 HIP 105797 19.52
2026-08-05 12:00 21:24:45.38 -00:40:31.9 HIP 105797 22.13
2026-08-06 00:00 21:24:07.00 -00:41:20.0 HIP 105588 15.01
2026-08-06 12:00 21:23:28.65 -00:42:09.1 HIP 105588 6.21
2026-08-07 00:00 21:22:50.34 -00:42:59.1 HIP 105588 6.06
2026-08-07 12:00 21:22:12.06 -00:43:50.0 HIP 105588 14.81
2026-08-08 00:00 21:21:33.82 -00:44:41.8 HIP 105549 22.85
2026-08-08 12:00 21:20:55.62 -00:45:34.4 HIP 105261 27.24
2026-08-09 00:00 21:20:17.48 -00:46:28.0 HIP 105261 19.80
2026-08-09 12:00 21:19:39.38 -00:47:22.3 HIP 105261 15.04
2026-08-10 00:00 21:19:01.35 -00:48:17.5 HIP 105261 15.61
2026-08-10 12:00 21:18:23.37 -00:49:13.6 HIP 105261 21.06
2026-08-11 00:00 21:17:45.46 -00:50:10.4 HIP 105066 18.09
2026-08-11 12:00 21:17:07.62 -00:51:08.0 HIP 105066 13.58
2026-08-12 00:00 21:16:29.86 -00:52:06.4 HIP 105040 14.85
2026-08-12 12:00 21:15:52.17 -00:53:05.6 HIP 104878 18.05
2026-08-13 00:00 21:15:14.57 -00:54:05.5 HIP 104878 9.35
2026-08-13 12:00 21:14:37.06 -00:55:06.1 HIP 104878 5.28
2026-08-14 00:00 21:13:59.64 -00:56:07.4 HIP 104878 12.08
2026-08-14 12:00 21:13:22.31 -00:57:09.5 HIP 104740 11.19
2026-08-15 00:00 21:12:45.08 -00:58:12.2 HIP 104740 11.16
2026-08-15 12:00 21:12:07.96 -00:59:15.5 HIP 104626 10.20
2026-08-16 00:00 21:11:30.95 -01:00:19.5 HIP 104626 8.27
2026-08-16 12:00 21:10:54.05 -01:01:24.1 HIP 104626 14.34
2026-08-17 00:00 21:10:17.26 -01:02:29.3 HIP 104626 22.69
2026-08-17 12:00 21:09:40.60 -01:03:35.1 HIP 104338 23.19
2026-08-18 00:00 21:09:04.06 -01:04:41.5 HIP 104338 14.67
2026-08-18 12:00 21:08:27.64 -01:05:48.5 HIP 104338 7.88
2026-08-19 00:00 21:07:51.36 -01:06:56.0 HIP 104338 8.79