| Parameter |
Value |
| Designation |
251P/LINEAR |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2004-06-19T01:47:38.279040Z |
| Orbit solution date (soln_date, UTC) |
2024-10-05T23:12:40Z |
| Obs used |
431 |
| NEO |
- |
| M1 |
12.000 |
| K1 |
24.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2007-04-11.0000000 |
| e |
0.50982311 |
| q (au) |
1.711672 |
| a (au) |
3.491948 |
| i (deg) |
23.507154 |
| Ω (om, deg) |
219.552911 |
| ω (w, deg) |
30.906733 |
| M (ma, deg) |
154.959455 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.255 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.255 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.719 |
| k |
0.978 |
| 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 |
04:03:20.01 |
+15:48:04.7 |
HIP 19120 |
41.56 |
| 2026-07-29 12:00 |
04:03:36.62 |
+15:47:46.6 |
HIP 19120 |
37.85 |
| 2026-07-30 00:00 |
04:03:53.11 |
+15:47:27.7 |
HIP 19120 |
34.24 |
| 2026-07-30 12:00 |
04:04:09.47 |
+15:47:08.2 |
HIP 19120 |
30.74 |
| 2026-07-31 00:00 |
04:04:25.70 |
+15:46:47.9 |
HIP 19148 |
27.00 |
| 2026-07-31 12:00 |
04:04:41.80 |
+15:46:27.0 |
HIP 19148 |
23.13 |
| 2026-08-01 00:00 |
04:04:57.77 |
+15:46:05.3 |
HIP 19148 |
19.30 |
| 2026-08-01 12:00 |
04:05:13.62 |
+15:45:43.0 |
HIP 19148 |
15.51 |
| 2026-08-02 00:00 |
04:05:29.33 |
+15:45:20.0 |
HIP 19148 |
11.76 |
| 2026-08-02 12:00 |
04:05:44.90 |
+15:44:56.3 |
HIP 19148 |
8.09 |
| 2026-08-03 00:00 |
04:06:00.35 |
+15:44:31.8 |
HIP 19148 |
4.61 |
| 2026-08-03 12:00 |
04:06:15.66 |
+15:44:06.7 |
HIP 19148 |
2.22 |
| 2026-08-04 00:00 |
04:06:30.83 |
+15:43:40.9 |
HIP 19148 |
3.98 |
| 2026-08-04 12:00 |
04:06:45.87 |
+15:43:14.3 |
HIP 19148 |
7.30 |
| 2026-08-05 00:00 |
04:07:00.77 |
+15:42:47.1 |
HIP 19148 |
10.80 |
| 2026-08-05 12:00 |
04:07:15.53 |
+15:42:19.1 |
HIP 19148 |
14.32 |
| 2026-08-06 00:00 |
04:07:30.15 |
+15:41:50.4 |
HIP 19148 |
17.83 |
| 2026-08-06 12:00 |
04:07:44.63 |
+15:41:21.1 |
HIP 19148 |
21.33 |
| 2026-08-07 00:00 |
04:07:58.97 |
+15:40:51.0 |
HIP 19148 |
24.79 |
| 2026-08-07 12:00 |
04:08:13.17 |
+15:40:20.2 |
HIP 19207 |
26.65 |
| 2026-08-08 00:00 |
04:08:27.22 |
+15:39:48.7 |
HIP 19451 |
24.70 |
| 2026-08-08 12:00 |
04:08:41.13 |
+15:39:16.4 |
HIP 19451 |
22.16 |
| 2026-08-09 00:00 |
04:08:54.89 |
+15:38:43.5 |
HIP 19451 |
19.92 |
| 2026-08-09 12:00 |
04:09:08.50 |
+15:38:09.8 |
HIP 19451 |
18.06 |
| 2026-08-10 00:00 |
04:09:21.97 |
+15:37:35.4 |
HIP 19451 |
16.69 |
| 2026-08-10 12:00 |
04:09:35.28 |
+15:37:00.3 |
HIP 19451 |
15.91 |
| 2026-08-11 00:00 |
04:09:48.45 |
+15:36:24.5 |
HIP 19451 |
15.79 |
| 2026-08-11 12:00 |
04:10:01.46 |
+15:35:48.0 |
HIP 19451 |
16.34 |
| 2026-08-12 00:00 |
04:10:14.32 |
+15:35:10.7 |
HIP 19548 |
13.74 |
| 2026-08-12 12:00 |
04:10:27.03 |
+15:34:32.8 |
HIP 19548 |
10.90 |
| 2026-08-13 00:00 |
04:10:39.58 |
+15:33:54.1 |
HIP 19548 |
8.30 |
| 2026-08-13 12:00 |
04:10:51.98 |
+15:33:14.7 |
HIP 19548 |
6.22 |
| 2026-08-14 00:00 |
04:11:04.22 |
+15:32:34.5 |
HIP 19548 |
5.22 |
| 2026-08-14 12:00 |
04:11:16.30 |
+15:31:53.7 |
HIP 19548 |
5.85 |
| 2026-08-15 00:00 |
04:11:28.23 |
+15:31:12.1 |
HIP 19548 |
7.67 |
| 2026-08-15 12:00 |
04:11:39.99 |
+15:30:29.8 |
HIP 19548 |
10.03 |
| 2026-08-16 00:00 |
04:11:51.59 |
+15:29:46.8 |
HIP 19548 |
12.60 |
| 2026-08-16 12:00 |
04:12:03.04 |
+15:29:03.1 |
HIP 19548 |
15.26 |
| 2026-08-17 00:00 |
04:12:14.32 |
+15:28:18.6 |
HIP 19548 |
17.95 |
| 2026-08-17 12:00 |
04:12:25.43 |
+15:27:33.4 |
HIP 19548 |
20.64 |
| 2026-08-18 00:00 |
04:12:36.39 |
+15:26:47.5 |
HIP 19548 |
23.33 |
| 2026-08-18 12:00 |
04:12:47.18 |
+15:26:00.9 |
HIP 19548 |
26.00 |
| 2026-08-19 00:00 |
04:12:57.80 |
+15:25:13.6 |
HIP 19548 |
28.65 |