| Parameter |
Value |
| Designation |
C/2002 E2 (Snyder-Murakami) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2002-02-21T19:01:43.622400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:15Z |
| Obs used |
905 |
| NEO |
- |
| M1 |
10.600 |
| K1 |
7.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2002-05-22.0000000 |
| e |
1.00078903 |
| q (au) |
1.466445 |
| a (au) |
-1858.536843 |
| i (deg) |
92.544982 |
| Ω (om, deg) |
244.582842 |
| ω (w, deg) |
9.034141 |
| M (ma, deg) |
0.001097 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.648 + 4.589\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.648 |
| n |
4.589 |
| gf |
0.980 |
| gb |
-1.000 |
| k |
0.992 |
| δ90 |
9.688 |
| 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 |
04:07:59.41 |
+32:37:03.0 |
HIP 19306 |
10.25 |
| 2026-07-29 12:00 |
04:08:00.77 |
+32:37:11.5 |
HIP 19306 |
10.27 |
| 2026-07-30 00:00 |
04:08:02.12 |
+32:37:20.0 |
HIP 19306 |
10.31 |
| 2026-07-30 12:00 |
04:08:03.44 |
+32:37:28.5 |
HIP 19306 |
10.36 |
| 2026-07-31 00:00 |
04:08:04.75 |
+32:37:36.9 |
HIP 19306 |
10.41 |
| 2026-07-31 12:00 |
04:08:06.03 |
+32:37:45.3 |
HIP 19306 |
10.48 |
| 2026-08-01 00:00 |
04:08:07.29 |
+32:37:53.7 |
HIP 19306 |
10.55 |
| 2026-08-01 12:00 |
04:08:08.53 |
+32:38:02.1 |
HIP 19306 |
10.63 |
| 2026-08-02 00:00 |
04:08:09.74 |
+32:38:10.5 |
HIP 19306 |
10.73 |
| 2026-08-02 12:00 |
04:08:10.94 |
+32:38:18.8 |
HIP 19306 |
10.82 |
| 2026-08-03 00:00 |
04:08:12.11 |
+32:38:27.1 |
HIP 19306 |
10.93 |
| 2026-08-03 12:00 |
04:08:13.26 |
+32:38:35.4 |
HIP 19306 |
11.04 |
| 2026-08-04 00:00 |
04:08:14.39 |
+32:38:43.6 |
HIP 19306 |
11.16 |
| 2026-08-04 12:00 |
04:08:15.49 |
+32:38:51.9 |
HIP 19306 |
11.28 |
| 2026-08-05 00:00 |
04:08:16.57 |
+32:39:00.1 |
HIP 19306 |
11.41 |
| 2026-08-05 12:00 |
04:08:17.63 |
+32:39:08.2 |
HIP 19306 |
11.54 |
| 2026-08-06 00:00 |
04:08:18.67 |
+32:39:16.4 |
HIP 19306 |
11.67 |
| 2026-08-06 12:00 |
04:08:19.68 |
+32:39:24.5 |
HIP 19306 |
11.81 |
| 2026-08-07 00:00 |
04:08:20.67 |
+32:39:32.6 |
HIP 19306 |
11.95 |
| 2026-08-07 12:00 |
04:08:21.64 |
+32:39:40.6 |
HIP 19306 |
12.10 |
| 2026-08-08 00:00 |
04:08:22.59 |
+32:39:48.7 |
HIP 19306 |
12.25 |
| 2026-08-08 12:00 |
04:08:23.51 |
+32:39:56.7 |
HIP 19306 |
12.39 |
| 2026-08-09 00:00 |
04:08:24.41 |
+32:40:04.6 |
HIP 19306 |
12.54 |
| 2026-08-09 12:00 |
04:08:25.28 |
+32:40:12.5 |
HIP 19306 |
12.70 |
| 2026-08-10 00:00 |
04:08:26.13 |
+32:40:20.4 |
HIP 19306 |
12.85 |
| 2026-08-10 12:00 |
04:08:26.96 |
+32:40:28.3 |
HIP 19306 |
13.00 |
| 2026-08-11 00:00 |
04:08:27.76 |
+32:40:36.1 |
HIP 19306 |
13.16 |
| 2026-08-11 12:00 |
04:08:28.54 |
+32:40:43.9 |
HIP 19306 |
13.31 |
| 2026-08-12 00:00 |
04:08:29.30 |
+32:40:51.6 |
HIP 19306 |
13.46 |
| 2026-08-12 12:00 |
04:08:30.03 |
+32:40:59.3 |
HIP 19306 |
13.62 |
| 2026-08-13 00:00 |
04:08:30.74 |
+32:41:07.0 |
HIP 19306 |
13.77 |
| 2026-08-13 12:00 |
04:08:31.43 |
+32:41:14.6 |
HIP 19306 |
13.92 |
| 2026-08-14 00:00 |
04:08:32.09 |
+32:41:22.2 |
HIP 19306 |
14.08 |
| 2026-08-14 12:00 |
04:08:32.72 |
+32:41:29.8 |
HIP 19306 |
14.23 |
| 2026-08-15 00:00 |
04:08:33.33 |
+32:41:37.3 |
HIP 19306 |
14.38 |
| 2026-08-15 12:00 |
04:08:33.92 |
+32:41:44.7 |
HIP 19306 |
14.53 |
| 2026-08-16 00:00 |
04:08:34.48 |
+32:41:52.2 |
HIP 19306 |
14.67 |
| 2026-08-16 12:00 |
04:08:35.02 |
+32:41:59.6 |
HIP 19306 |
14.82 |
| 2026-08-17 00:00 |
04:08:35.53 |
+32:42:06.9 |
HIP 19306 |
14.97 |
| 2026-08-17 12:00 |
04:08:36.02 |
+32:42:14.2 |
HIP 19306 |
15.11 |
| 2026-08-18 00:00 |
04:08:36.49 |
+32:42:21.4 |
HIP 19306 |
15.25 |
| 2026-08-18 12:00 |
04:08:36.93 |
+32:42:28.6 |
HIP 19306 |
15.39 |
| 2026-08-19 00:00 |
04:08:37.34 |
+32:42:35.8 |
HIP 19306 |
15.53 |