197P/LINEAR

Metadata

Parameter Value
Designation 197P/LINEAR
Type P
Perihelion (tp_cal, UTC) 2008-05-18T23:56:01.968000Z
Orbit solution date (soln_date, UTC) 2023-10-20T22:43:21Z
Obs used 325
NEO Yes
M1 18.200
K1 5.750
PC 0.030
Osculating Elements
Parameter Value
Epoch (epoch_cal, TDB) 2006-09-26.0000000
e 0.62994097
q (au) 1.061109
a (au) 2.867406
i (deg) 25.556064
Ω (om, deg) 66.395886
ω (w, deg) 188.752044
M (ma, deg) 238.004767

Magnitude

197P/LINEAR · Magnitude (Full range)

Scatter + Global Linear

$$ M_a = (20.000 + 3.342\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

Model Parameters

Parameter Value
H0 20.000
n 3.342
gf 0.971
gb -1.000
k 0.969
δ90 4.109
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 05:10:34.49 +34:29:58.9 HIP 23998 25.41
2026-03-26 12:00 05:10:50.44 +34:29:50.4 HIP 23998 27.30
2026-03-27 00:00 05:11:06.61 +34:29:42.2 HIP 24288 28.21
2026-03-27 12:00 05:11:22.98 +34:29:34.4 HIP 24288 26.01
2026-03-28 00:00 05:11:39.57 +34:29:26.9 HIP 24288 24.05
2026-03-28 12:00 05:11:56.37 +34:29:19.8 HIP 24288 22.41
2026-03-29 00:00 05:12:13.37 +34:29:13.1 HIP 24288 21.20
2026-03-29 12:00 05:12:30.58 +34:29:06.7 HIP 24288 20.51
2026-03-30 00:00 05:12:47.99 +34:29:00.6 HIP 24288 20.41
2026-03-30 12:00 05:13:05.61 +34:28:54.8 HIP 24288 20.94
2026-03-31 00:00 05:13:23.43 +34:28:49.4 HIP 24288 22.06
2026-03-31 12:00 05:13:41.45 +34:28:44.3 HIP 24288 23.73
2026-04-01 00:00 05:13:59.67 +34:28:39.6 HIP 24538 23.63
2026-04-01 12:00 05:14:18.08 +34:28:35.1 HIP 24538 19.86
2026-04-02 00:00 05:14:36.69 +34:28:31.0 HIP 24538 16.07
2026-04-02 12:00 05:14:55.50 +34:28:27.2 HIP 24538 12.28
2026-04-03 00:00 05:15:14.50 +34:28:23.7 HIP 24538 8.52
2026-04-03 12:00 05:15:33.69 +34:28:20.5 HIP 24538 4.98
2026-04-04 00:00 05:15:53.08 +34:28:17.6 HIP 24538 2.89
2026-04-04 12:00 05:16:12.65 +34:28:15.0 HIP 24538 4.92
2026-04-05 00:00 05:16:32.41 +34:28:12.7 HIP 24538 8.56
2026-04-05 12:00 05:16:52.36 +34:28:10.7 HIP 24575 11.79
2026-04-06 00:00 05:17:12.50 +34:28:09.0 HIP 24575 14.64
2026-04-06 12:00 05:17:32.82 +34:28:07.6 HIP 24575 18.04
2026-04-07 00:00 05:17:53.32 +34:28:06.5 HIP 24575 21.76
2026-04-07 12:00 05:18:14.01 +34:28:05.6 HIP 24575 25.67
2026-04-08 00:00 05:18:34.88 +34:28:05.0 HIP 24821 26.68
2026-04-08 12:00 05:18:55.93 +34:28:04.7 HIP 24821 25.67
2026-04-09 00:00 05:19:17.16 +34:28:04.6 HIP 24962 22.61
2026-04-09 12:00 05:19:38.57 +34:28:04.9 HIP 24962 19.02
2026-04-10 00:00 05:20:00.15 +34:28:05.3 HIP 24962 15.83
2026-04-10 12:00 05:20:21.91 +34:28:06.1 HIP 24962 13.37
2026-04-11 00:00 05:20:43.85 +34:28:07.0 HIP 24962 12.13
2026-04-11 12:00 05:21:05.96 +34:28:08.3 HIP 24962 12.53
2026-04-12 00:00 05:21:28.24 +34:28:09.7 HIP 24962 14.46
2026-04-12 12:00 05:21:50.69 +34:28:11.5 HIP 25030 16.74
2026-04-13 00:00 05:22:13.31 +34:28:13.4 HIP 25030 18.16
2026-04-13 12:00 05:22:36.10 +34:28:15.6 HIP 25030 20.58
2026-04-14 00:00 05:22:59.06 +34:28:18.0 HIP 25030 23.71
2026-04-14 12:00 05:23:22.18 +34:28:20.7 HIP 25030 27.33
2026-04-15 00:00 05:23:45.48 +34:28:23.5 HIP 25357 26.80
2026-04-15 12:00 05:24:08.93 +34:28:26.6 HIP 25357 23.47
2026-04-16 00:00 05:24:32.55 +34:28:29.9 HIP 25357 20.73