70P/Kojima

Metadata

Parameter Value
Designation 70P/Kojima
Type P
Perihelion (tp_cal, UTC) 2014-10-20T16:00:34.519680Z
Orbit solution date (soln_date, UTC) 2026-05-06T05:40:47Z
Obs used 2097
NEO -
M1 12.500
K1 11.000
PC 0.030
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2015-05-14.0000000
e 0.45391285
q (au) 2.006566
a (au) 3.674443
i (deg) 6.600119
Ω (om, deg) 119.270141
ω (w, deg) 1.953402
M (ma, deg) 28.732632

Magnitude

70P/Kojima · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (11.329 + 5.287\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 11.329
n 5.287
gf 1.000
gb -0.745
k 0.994
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

Residuals (Piecewise)

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

Start (UTC) End (UTC) a b
2020-09-09 2021-09-27 -4.6159 +1.433
2021-09-27 2022-06-17 +13.1079 -6.435

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

Ephemeris

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-05-12 00:00 22:28:55.80 -12:20:00.0 HIP 110902 29.00
2026-05-12 12:00 22:29:09.32 -12:19:09.9 HIP 110902 29.75
2026-05-13 00:00 22:29:22.71 -12:18:20.6 HIP 110902 30.85
2026-05-13 12:00 22:29:35.96 -12:17:32.3 HIP 110902 32.25
2026-05-14 00:00 22:29:49.08 -12:16:44.7 HIP 111044 33.90
2026-05-14 12:00 22:30:02.06 -12:15:58.1 HIP 111044 33.36
2026-05-15 00:00 22:30:14.91 -12:15:12.3 HIP 111044 33.13
2026-05-15 12:00 22:30:27.61 -12:14:27.5 HIP 111044 33.23
2026-05-16 00:00 22:30:40.18 -12:13:43.5 HIP 111044 33.63
2026-05-16 12:00 22:30:52.60 -12:13:00.4 HIP 111044 34.32
2026-05-17 00:00 22:31:04.88 -12:12:18.2 HIP 111044 35.26
2026-05-17 12:00 22:31:17.03 -12:11:37.0 HIP 111044 36.43
2026-05-18 00:00 22:31:29.02 -12:10:56.6 HIP 111376 36.25
2026-05-18 12:00 22:31:40.88 -12:10:17.2 HIP 111376 33.79
2026-05-19 00:00 22:31:52.59 -12:09:38.7 HIP 111376 31.45
2026-05-19 12:00 22:32:04.15 -12:09:01.1 HIP 111376 29.23
2026-05-20 00:00 22:32:15.57 -12:08:24.5 HIP 111396 26.67
2026-05-20 12:00 22:32:26.84 -12:07:48.8 HIP 111396 23.95
2026-05-21 00:00 22:32:37.96 -12:07:14.1 HIP 111396 21.29
2026-05-21 12:00 22:32:48.94 -12:06:40.4 HIP 111396 18.70
2026-05-22 00:00 22:32:59.76 -12:06:07.5 HIP 111396 16.20
2026-05-22 12:00 22:33:10.44 -12:05:35.7 HIP 111396 13.80
2026-05-23 00:00 22:33:20.97 -12:05:04.8 HIP 111396 11.54
2026-05-23 12:00 22:33:31.34 -12:04:34.9 HIP 111396 9.50
2026-05-24 00:00 22:33:41.56 -12:04:06.0 HIP 111396 7.80
2026-05-24 12:00 22:33:51.63 -12:03:38.0 HIP 111396 6.66
2026-05-25 00:00 22:34:01.55 -12:03:11.1 HIP 111396 6.35
2026-05-25 12:00 22:34:11.31 -12:02:45.1 HIP 111396 6.94
2026-05-26 00:00 22:34:20.92 -12:02:20.1 HIP 111396 8.20
2026-05-26 12:00 22:34:30.37 -12:01:56.1 HIP 111396 9.84
2026-05-27 00:00 22:34:39.67 -12:01:33.2 HIP 111396 11.69
2026-05-27 12:00 22:34:48.81 -12:01:11.2 HIP 111396 13.63
2026-05-28 00:00 22:34:57.79 -12:00:50.3 HIP 111396 15.62
2026-05-28 12:00 22:35:06.61 -12:00:30.3 HIP 111396 17.63
2026-05-29 00:00 22:35:15.28 -12:00:11.4 HIP 111396 19.63
2026-05-29 12:00 22:35:23.78 -11:59:53.6 HIP 111396 21.61
2026-05-30 00:00 22:35:32.13 -11:59:36.7 HIP 111396 23.57
2026-05-30 12:00 22:35:40.31 -11:59:20.9 HIP 111396 25.51
2026-05-31 00:00 22:35:48.33 -11:59:06.2 HIP 111652 24.42
2026-05-31 12:00 22:35:56.19 -11:58:52.5 HIP 111652 22.80
2026-06-01 00:00 22:36:03.88 -11:58:39.8 HIP 111652 21.27
2026-06-01 12:00 22:36:11.41 -11:58:28.2 HIP 111652 19.84
2026-06-02 00:00 22:36:18.77 -11:58:17.7 HIP 111652 18.53