2P/Encke
| Parameter |
Value |
| Designation |
2P/Encke |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2023-10-22T03:35:18.398400Z |
| Orbit solution date (soln_date, UTC) |
2025-12-15T09:34:26Z |
| Obs used |
640 |
| NEO |
Yes |
| M1 |
15.600 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2022-09-25.0000000 |
| e |
0.84774970 |
| q (au) |
0.337948 |
| a (au) |
2.219689 |
| i (deg) |
11.412278 |
| Ω (om, deg) |
334.193585 |
| ω (w, deg) |
187.134246 |
| M (ma, deg) |
243.126069 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.799 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.799 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
22:58:36.23 |
-03:19:17.1 |
HIP 113355 |
20.13 |
| 2026-02-03 12:00 |
22:59:01.59 |
-03:16:34.0 |
HIP 113523 |
24.43 |
| 2026-02-04 00:00 |
22:59:27.03 |
-03:13:50.3 |
HIP 113523 |
20.71 |
| 2026-02-04 12:00 |
22:59:52.54 |
-03:11:05.9 |
HIP 113523 |
18.88 |
| 2026-02-05 00:00 |
23:00:18.12 |
-03:08:20.9 |
HIP 113555 |
17.61 |
| 2026-02-05 12:00 |
23:00:43.77 |
-03:05:35.1 |
HIP 113555 |
18.07 |
| 2026-02-06 00:00 |
23:01:09.50 |
-03:02:48.7 |
HIP 113555 |
20.99 |
| 2026-02-06 12:00 |
23:01:35.29 |
-03:00:01.7 |
HIP 113727 |
19.52 |
| 2026-02-07 00:00 |
23:02:01.15 |
-02:57:14.0 |
HIP 113727 |
16.14 |
| 2026-02-07 12:00 |
23:02:27.09 |
-02:54:25.7 |
HIP 113727 |
15.45 |
| 2026-02-08 00:00 |
23:02:53.08 |
-02:51:36.7 |
HIP 113727 |
17.80 |
| 2026-02-08 12:00 |
23:03:19.15 |
-02:48:47.1 |
HIP 113727 |
22.26 |
| 2026-02-09 00:00 |
23:03:45.28 |
-02:45:56.9 |
HIP 113727 |
27.85 |
| 2026-02-09 12:00 |
23:04:11.48 |
-02:43:06.0 |
HIP 113727 |
34.04 |
| 2026-02-10 00:00 |
23:04:37.75 |
-02:40:14.5 |
HIP 113727 |
40.55 |
| 2026-02-10 12:00 |
23:05:04.07 |
-02:37:22.4 |
HIP 113931 |
44.85 |
| 2026-02-11 00:00 |
23:05:30.46 |
-02:34:29.6 |
HIP 114202 |
43.00 |
| 2026-02-11 12:00 |
23:05:56.92 |
-02:31:36.2 |
HIP 114202 |
36.18 |
| 2026-02-12 00:00 |
23:06:23.44 |
-02:28:42.3 |
HIP 114202 |
29.53 |
| 2026-02-12 12:00 |
23:06:50.01 |
-02:25:47.7 |
HIP 114202 |
23.20 |
| 2026-02-13 00:00 |
23:07:16.65 |
-02:22:52.5 |
HIP 114202 |
17.59 |
| 2026-02-13 12:00 |
23:07:43.35 |
-02:19:56.7 |
HIP 114202 |
13.64 |
| 2026-02-14 00:00 |
23:08:10.11 |
-02:17:00.4 |
HIP 114202 |
12.99 |
| 2026-02-14 12:00 |
23:08:36.93 |
-02:14:03.4 |
HIP 114322 |
8.50 |
| 2026-02-15 00:00 |
23:09:03.80 |
-02:11:05.9 |
HIP 114322 |
4.82 |
| 2026-02-15 12:00 |
23:09:30.74 |
-02:08:07.7 |
HIP 114322 |
9.07 |
| 2026-02-16 00:00 |
23:09:57.72 |
-02:05:09.0 |
HIP 114322 |
15.81 |
| 2026-02-16 12:00 |
23:10:24.77 |
-02:02:09.8 |
HIP 114322 |
22.96 |
| 2026-02-17 00:00 |
23:10:51.87 |
-01:59:09.9 |
HIP 114551 |
20.58 |
| 2026-02-17 12:00 |
23:11:19.02 |
-01:56:09.6 |
HIP 114551 |
15.03 |
| 2026-02-18 00:00 |
23:11:46.23 |
-01:53:08.6 |
HIP 114551 |
11.75 |
| 2026-02-18 12:00 |
23:12:13.49 |
-01:50:07.1 |
HIP 114551 |
12.70 |
| 2026-02-19 00:00 |
23:12:40.80 |
-01:47:05.1 |
HIP 114551 |
17.20 |
| 2026-02-19 12:00 |
23:13:08.16 |
-01:44:02.5 |
HIP 114618 |
19.72 |
| 2026-02-20 00:00 |
23:13:35.57 |
-01:40:59.4 |
HIP 114618 |
23.46 |
| 2026-02-20 12:00 |
23:14:03.03 |
-01:37:55.7 |
HIP 114618 |
28.73 |
| 2026-02-21 00:00 |
23:14:30.54 |
-01:34:51.5 |
HIP 114864 |
23.87 |
| 2026-02-21 12:00 |
23:14:58.10 |
-01:31:46.9 |
HIP 114864 |
16.33 |
| 2026-02-22 00:00 |
23:15:25.70 |
-01:28:41.7 |
HIP 114864 |
8.78 |
| 2026-02-22 12:00 |
23:15:53.35 |
-01:25:35.9 |
HIP 114864 |
1.25 |
| 2026-02-23 00:00 |
23:16:21.05 |
-01:22:29.7 |
HIP 114864 |
6.40 |
| 2026-02-23 12:00 |
23:16:48.79 |
-01:19:23.0 |
HIP 114864 |
13.99 |
| 2026-02-24 00:00 |
23:17:16.58 |
-01:16:15.8 |
HIP 115012 |
15.91 |