| Parameter |
Value |
| Designation |
187P/LINEAR |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2008-10-22T14:00:37.010880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:27:48Z |
| Obs used |
296 |
| NEO |
- |
| M1 |
7.300 |
| K1 |
16.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-02-09.0000000 |
| e |
0.17318236 |
| q (au) |
3.715328 |
| a (au) |
4.493528 |
| i (deg) |
13.655086 |
| Ω (om, deg) |
111.736093 |
| ω (w, deg) |
134.735817 |
| M (ma, deg) |
86.856101 |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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 |
10:08:29.68 |
+24:03:09.7 |
HIP 49628 |
11.17 |
| 2026-03-26 12:00 |
10:08:18.28 |
+24:03:53.7 |
HIP 49628 |
9.08 |
| 2026-03-27 00:00 |
10:08:07.07 |
+24:04:36.0 |
HIP 49628 |
7.41 |
| 2026-03-27 12:00 |
10:07:56.05 |
+24:05:16.6 |
HIP 49628 |
6.45 |
| 2026-03-28 00:00 |
10:07:45.24 |
+24:05:55.4 |
HIP 49628 |
6.43 |
| 2026-03-28 12:00 |
10:07:34.61 |
+24:06:32.6 |
HIP 49628 |
7.32 |
| 2026-03-29 00:00 |
10:07:24.19 |
+24:07:07.9 |
HIP 49628 |
8.80 |
| 2026-03-29 12:00 |
10:07:13.97 |
+24:07:41.6 |
HIP 49628 |
10.60 |
| 2026-03-30 00:00 |
10:07:03.95 |
+24:08:13.5 |
HIP 49628 |
12.55 |
| 2026-03-30 12:00 |
10:06:54.13 |
+24:08:43.8 |
HIP 49628 |
14.56 |
| 2026-03-31 00:00 |
10:06:44.52 |
+24:09:12.3 |
HIP 49628 |
16.59 |
| 2026-03-31 12:00 |
10:06:35.12 |
+24:09:39.1 |
HIP 49628 |
18.61 |
| 2026-04-01 00:00 |
10:06:25.92 |
+24:10:04.2 |
HIP 49478 |
20.42 |
| 2026-04-01 12:00 |
10:06:16.93 |
+24:10:27.6 |
HIP 49478 |
20.49 |
| 2026-04-02 00:00 |
10:06:08.15 |
+24:10:49.3 |
HIP 49478 |
20.74 |
| 2026-04-02 12:00 |
10:05:59.59 |
+24:11:09.4 |
HIP 49478 |
21.16 |
| 2026-04-03 00:00 |
10:05:51.23 |
+24:11:27.7 |
HIP 49478 |
21.71 |
| 2026-04-03 12:00 |
10:05:43.09 |
+24:11:44.4 |
HIP 49478 |
22.38 |
| 2026-04-04 00:00 |
10:05:35.17 |
+24:11:59.4 |
HIP 49478 |
23.14 |
| 2026-04-04 12:00 |
10:05:27.46 |
+24:12:12.8 |
HIP 49478 |
23.97 |
| 2026-04-05 00:00 |
10:05:19.97 |
+24:12:24.5 |
HIP 49478 |
24.85 |
| 2026-04-05 12:00 |
10:05:12.70 |
+24:12:34.5 |
HIP 49478 |
25.77 |
| 2026-04-06 00:00 |
10:05:05.65 |
+24:12:42.9 |
HIP 49478 |
26.71 |
| 2026-04-06 12:00 |
10:04:58.82 |
+24:12:49.6 |
HIP 49478 |
27.66 |
| 2026-04-07 00:00 |
10:04:52.21 |
+24:12:54.7 |
HIP 49478 |
28.62 |
| 2026-04-07 12:00 |
10:04:45.82 |
+24:12:58.2 |
HIP 49478 |
29.57 |
| 2026-04-08 00:00 |
10:04:39.66 |
+24:13:00.1 |
HIP 49478 |
30.50 |
| 2026-04-08 12:00 |
10:04:33.72 |
+24:13:00.3 |
HIP 49478 |
31.41 |
| 2026-04-09 00:00 |
10:04:28.01 |
+24:12:58.9 |
HIP 49478 |
32.30 |
| 2026-04-09 12:00 |
10:04:22.52 |
+24:12:55.9 |
HIP 49478 |
33.16 |
| 2026-04-10 00:00 |
10:04:17.26 |
+24:12:51.3 |
HIP 49478 |
33.99 |
| 2026-04-10 12:00 |
10:04:12.23 |
+24:12:45.1 |
HIP 49153 |
34.66 |
| 2026-04-11 00:00 |
10:04:07.42 |
+24:12:37.3 |
HIP 49153 |
33.61 |
| 2026-04-11 12:00 |
10:04:02.84 |
+24:12:28.0 |
HIP 49153 |
32.59 |
| 2026-04-12 00:00 |
10:03:58.50 |
+24:12:17.0 |
HIP 49153 |
31.62 |
| 2026-04-12 12:00 |
10:03:54.38 |
+24:12:04.5 |
HIP 49153 |
30.68 |
| 2026-04-13 00:00 |
10:03:50.50 |
+24:11:50.5 |
HIP 49153 |
29.78 |
| 2026-04-13 12:00 |
10:03:46.85 |
+24:11:34.8 |
HIP 49153 |
28.92 |
| 2026-04-14 00:00 |
10:03:43.42 |
+24:11:17.7 |
HIP 49153 |
28.09 |
| 2026-04-14 12:00 |
10:03:40.24 |
+24:10:59.0 |
HIP 49153 |
27.30 |
| 2026-04-15 00:00 |
10:03:37.28 |
+24:10:38.7 |
HIP 49153 |
26.55 |
| 2026-04-15 12:00 |
10:03:34.56 |
+24:10:16.9 |
HIP 49153 |
25.83 |
| 2026-04-16 00:00 |
10:03:32.07 |
+24:09:53.7 |
HIP 49153 |
25.15 |