381P/LINEAR-Spacewatch
| Parameter |
Value |
| Designation |
381P/LINEAR-Spacewatch |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2019-09-29T17:41:23.599680Z |
| Orbit solution date (soln_date, UTC) |
2021-05-02T23:43:03Z |
| Obs used |
175 |
| NEO |
- |
| M1 |
13.600 |
| K1 |
14.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2019-05-29T13:47:59.136000Z |
| Discovery magnitude (MPC) |
21.60 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-07-10.0000000 |
| e |
0.67945045 |
| q (au) |
2.283195 |
| a (au) |
7.122754 |
| i (deg) |
28.462310 |
| Ω (om, deg) |
174.108452 |
| ω (w, deg) |
172.544217 |
| M (ma, deg) |
280.012136 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.792 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.792 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.831 |
| k |
0.996 |
| 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) |
| 2026-02-03 00:00 |
10:10:37.86 |
-01:17:13.5 |
HIP 49910 |
25.28 |
| 2026-02-03 12:00 |
10:10:29.30 |
-01:16:22.8 |
HIP 49910 |
27.05 |
| 2026-02-04 00:00 |
10:10:20.71 |
-01:15:31.5 |
HIP 49753 |
28.51 |
| 2026-02-04 12:00 |
10:10:12.10 |
-01:14:39.8 |
HIP 49753 |
28.25 |
| 2026-02-05 00:00 |
10:10:03.45 |
-01:13:47.6 |
HIP 49753 |
28.19 |
| 2026-02-05 12:00 |
10:09:54.78 |
-01:12:54.9 |
HIP 49753 |
28.33 |
| 2026-02-06 00:00 |
10:09:46.07 |
-01:12:01.7 |
HIP 49753 |
28.66 |
| 2026-02-06 12:00 |
10:09:37.35 |
-01:11:08.1 |
HIP 49753 |
29.18 |
| 2026-02-07 00:00 |
10:09:28.59 |
-01:10:14.0 |
HIP 49753 |
29.90 |
| 2026-02-07 12:00 |
10:09:19.82 |
-01:09:19.4 |
HIP 49753 |
30.78 |
| 2026-02-08 00:00 |
10:09:11.02 |
-01:08:24.3 |
HIP 49753 |
31.82 |
| 2026-02-08 12:00 |
10:09:02.20 |
-01:07:28.8 |
HIP 49753 |
33.02 |
| 2026-02-09 00:00 |
10:08:53.35 |
-01:06:32.9 |
HIP 49753 |
34.34 |
| 2026-02-09 12:00 |
10:08:44.49 |
-01:05:36.5 |
HIP 49753 |
35.79 |
| 2026-02-10 00:00 |
10:08:35.61 |
-01:04:39.7 |
HIP 49753 |
37.34 |
| 2026-02-10 12:00 |
10:08:26.71 |
-01:03:42.4 |
HIP 49753 |
39.00 |
| 2026-02-11 00:00 |
10:08:17.79 |
-01:02:44.7 |
HIP 49493 |
40.50 |
| 2026-02-11 12:00 |
10:08:08.86 |
-01:01:46.6 |
HIP 49493 |
39.53 |
| 2026-02-12 00:00 |
10:07:59.91 |
-01:00:48.0 |
HIP 49641 |
38.51 |
| 2026-02-12 12:00 |
10:07:50.95 |
-00:59:49.1 |
HIP 49641 |
37.54 |
| 2026-02-13 00:00 |
10:07:41.98 |
-00:58:49.7 |
HIP 49641 |
36.71 |
| 2026-02-13 12:00 |
10:07:32.99 |
-00:57:49.9 |
HIP 49641 |
36.01 |
| 2026-02-14 00:00 |
10:07:23.99 |
-00:56:49.8 |
HIP 49641 |
35.46 |
| 2026-02-14 12:00 |
10:07:14.99 |
-00:55:49.2 |
HIP 49641 |
35.08 |
| 2026-02-15 00:00 |
10:07:05.97 |
-00:54:48.3 |
HIP 49641 |
34.86 |
| 2026-02-15 12:00 |
10:06:56.95 |
-00:53:46.9 |
HIP 49641 |
34.80 |
| 2026-02-16 00:00 |
10:06:47.93 |
-00:52:45.3 |
HIP 49641 |
34.92 |
| 2026-02-16 12:00 |
10:06:38.89 |
-00:51:43.2 |
HIP 49390 |
34.01 |
| 2026-02-17 00:00 |
10:06:29.86 |
-00:50:40.8 |
HIP 49390 |
31.65 |
| 2026-02-17 12:00 |
10:06:20.82 |
-00:49:38.0 |
HIP 49390 |
29.32 |
| 2026-02-18 00:00 |
10:06:11.78 |
-00:48:34.9 |
HIP 49390 |
27.01 |
| 2026-02-18 12:00 |
10:06:02.73 |
-00:47:31.4 |
HIP 49390 |
24.73 |
| 2026-02-19 00:00 |
10:05:53.69 |
-00:46:27.6 |
HIP 49390 |
22.49 |
| 2026-02-19 12:00 |
10:05:44.65 |
-00:45:23.5 |
HIP 49390 |
20.31 |
| 2026-02-20 00:00 |
10:05:35.62 |
-00:44:19.0 |
HIP 49390 |
18.20 |
| 2026-02-20 12:00 |
10:05:26.58 |
-00:43:14.3 |
HIP 49390 |
16.20 |
| 2026-02-21 00:00 |
10:05:17.55 |
-00:42:09.2 |
HIP 49390 |
14.36 |
| 2026-02-21 12:00 |
10:05:08.53 |
-00:41:03.8 |
HIP 49390 |
12.74 |
| 2026-02-22 00:00 |
10:04:59.52 |
-00:39:58.2 |
HIP 49390 |
11.44 |
| 2026-02-22 12:00 |
10:04:50.51 |
-00:38:52.2 |
HIP 49390 |
10.58 |
| 2026-02-23 00:00 |
10:04:41.51 |
-00:37:46.0 |
HIP 49390 |
10.26 |
| 2026-02-23 12:00 |
10:04:32.52 |
-00:36:39.5 |
HIP 49390 |
10.55 |
| 2026-02-24 00:00 |
10:04:23.55 |
-00:35:32.7 |
HIP 49390 |
11.38 |