| Parameter |
Value |
| Designation |
77P/Longmore |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2016-05-14T10:40:08.040000Z |
| Orbit solution date (soln_date, UTC) |
2025-10-29T22:11:34Z |
| Obs used |
2629 |
| NEO |
- |
| M1 |
9.300 |
| K1 |
14.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-02-05.0000000 |
| e |
0.35416745 |
| q (au) |
2.333302 |
| a (au) |
3.612860 |
| i (deg) |
24.340171 |
| Ω (om, deg) |
14.886903 |
| ω (w, deg) |
196.946173 |
| M (ma, deg) |
240.954013 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.016 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.016 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.866 |
| k |
1.000 |
| 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) |
| 2026-05-12 00:00 |
01:34:42.89 |
+12:41:38.7 |
HIP 7364 |
8.40 |
| 2026-05-12 12:00 |
01:35:05.85 |
+12:44:45.5 |
HIP 7367 |
11.64 |
| 2026-05-13 00:00 |
01:35:28.78 |
+12:47:52.1 |
HIP 7367 |
16.79 |
| 2026-05-13 12:00 |
01:35:51.67 |
+12:50:58.5 |
HIP 7367 |
22.58 |
| 2026-05-14 00:00 |
01:36:14.52 |
+12:54:04.6 |
HIP 7621 |
28.34 |
| 2026-05-14 12:00 |
01:36:37.33 |
+12:57:10.5 |
HIP 7621 |
23.48 |
| 2026-05-15 00:00 |
01:37:00.10 |
+13:00:16.2 |
HIP 7621 |
19.51 |
| 2026-05-15 12:00 |
01:37:22.83 |
+13:03:21.6 |
HIP 7621 |
17.05 |
| 2026-05-16 00:00 |
01:37:45.51 |
+13:06:26.8 |
HIP 7621 |
16.77 |
| 2026-05-16 12:00 |
01:38:08.15 |
+13:09:31.8 |
HIP 7621 |
18.76 |
| 2026-05-17 00:00 |
01:38:30.75 |
+13:12:36.5 |
HIP 7621 |
22.41 |
| 2026-05-17 12:00 |
01:38:53.31 |
+13:15:41.0 |
HIP 7653 |
23.62 |
| 2026-05-18 00:00 |
01:39:15.81 |
+13:18:45.2 |
HIP 7653 |
22.54 |
| 2026-05-18 12:00 |
01:39:38.28 |
+13:21:49.1 |
HIP 7653 |
23.16 |
| 2026-05-19 00:00 |
01:40:00.69 |
+13:24:52.8 |
HIP 7653 |
25.35 |
| 2026-05-19 12:00 |
01:40:23.06 |
+13:27:56.3 |
HIP 7859 |
21.04 |
| 2026-05-20 00:00 |
01:40:45.38 |
+13:30:59.5 |
HIP 7859 |
16.11 |
| 2026-05-20 12:00 |
01:41:07.64 |
+13:34:02.4 |
HIP 7859 |
12.40 |
| 2026-05-21 00:00 |
01:41:29.86 |
+13:37:05.1 |
HIP 7859 |
11.19 |
| 2026-05-21 12:00 |
01:41:52.03 |
+13:40:07.5 |
HIP 7859 |
13.16 |
| 2026-05-22 00:00 |
01:42:14.15 |
+13:43:09.6 |
HIP 7859 |
17.24 |
| 2026-05-22 12:00 |
01:42:36.21 |
+13:46:11.5 |
HIP 7859 |
22.29 |
| 2026-05-23 00:00 |
01:42:58.23 |
+13:49:13.0 |
HIP 8126 |
25.41 |
| 2026-05-23 12:00 |
01:43:20.18 |
+13:52:14.4 |
HIP 8126 |
19.31 |
| 2026-05-24 00:00 |
01:43:42.09 |
+13:55:15.4 |
HIP 8126 |
13.24 |
| 2026-05-24 12:00 |
01:44:03.94 |
+13:58:16.2 |
HIP 8126 |
7.26 |
| 2026-05-25 00:00 |
01:44:25.73 |
+14:01:16.6 |
HIP 8126 |
2.13 |
| 2026-05-25 12:00 |
01:44:47.47 |
+14:04:16.9 |
HIP 8126 |
5.49 |
| 2026-05-26 00:00 |
01:45:09.15 |
+14:07:16.8 |
HIP 8126 |
11.36 |
| 2026-05-26 12:00 |
01:45:30.78 |
+14:10:16.4 |
HIP 8126 |
17.34 |
| 2026-05-27 00:00 |
01:45:52.35 |
+14:13:15.8 |
HIP 8126 |
23.33 |
| 2026-05-27 12:00 |
01:46:13.86 |
+14:16:14.8 |
HIP 8126 |
29.32 |
| 2026-05-28 00:00 |
01:46:35.31 |
+14:19:13.6 |
HIP 8426 |
33.80 |
| 2026-05-28 12:00 |
01:46:56.70 |
+14:22:12.1 |
HIP 8426 |
30.97 |
| 2026-05-29 00:00 |
01:47:18.03 |
+14:25:10.3 |
HIP 8426 |
29.12 |
| 2026-05-29 12:00 |
01:47:39.29 |
+14:28:08.3 |
HIP 8426 |
28.44 |
| 2026-05-30 00:00 |
01:48:00.50 |
+14:31:05.9 |
HIP 8426 |
28.98 |
| 2026-05-30 12:00 |
01:48:21.65 |
+14:34:03.2 |
HIP 8539 |
28.29 |
| 2026-05-31 00:00 |
01:48:42.73 |
+14:37:00.3 |
HIP 8539 |
25.59 |
| 2026-05-31 12:00 |
01:49:03.75 |
+14:39:57.0 |
HIP 8539 |
24.07 |
| 2026-06-01 00:00 |
01:49:24.70 |
+14:42:53.4 |
HIP 8539 |
23.95 |
| 2026-06-01 12:00 |
01:49:45.59 |
+14:45:49.6 |
HIP 8539 |
25.22 |
| 2026-06-02 00:00 |
01:50:06.41 |
+14:48:45.4 |
HIP 8568 |
24.03 |