| Parameter |
Value |
| Designation |
293P/Spacewatch |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2014-01-10T06:55:08.644800Z |
| Orbit solution date (soln_date, UTC) |
2022-06-12T21:06:40Z |
| Obs used |
463 |
| NEO |
- |
| M1 |
15.800 |
| K1 |
7.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-01-02.0000000 |
| e |
0.41974111 |
| q (au) |
2.111752 |
| a (au) |
3.639328 |
| i (deg) |
9.064844 |
| Ω (om, deg) |
78.437790 |
| ω (w, deg) |
41.152848 |
| M (ma, deg) |
358.823377 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.488 + 2.988\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.488 |
| n |
2.988 |
| gf |
0.999 |
| gb |
-0.716 |
| k |
0.994 |
| 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 |
00:25:27.36 |
-05:47:17.7 |
HIP 2044 |
18.24 |
| 2026-05-12 12:00 |
00:25:55.13 |
-05:44:50.0 |
HIP 2044 |
19.23 |
| 2026-05-13 00:00 |
00:26:22.83 |
-05:42:23.0 |
HIP 2117 |
13.23 |
| 2026-05-13 12:00 |
00:26:50.48 |
-05:39:56.7 |
HIP 2117 |
8.59 |
| 2026-05-14 00:00 |
00:27:18.08 |
-05:37:31.1 |
HIP 2117 |
8.90 |
| 2026-05-14 12:00 |
00:27:45.61 |
-05:35:06.2 |
HIP 2119 |
13.72 |
| 2026-05-15 00:00 |
00:28:13.09 |
-05:32:42.0 |
HIP 2298 |
17.30 |
| 2026-05-15 12:00 |
00:28:40.51 |
-05:30:18.5 |
HIP 2298 |
12.35 |
| 2026-05-16 00:00 |
00:29:07.87 |
-05:27:55.8 |
HIP 2298 |
10.49 |
| 2026-05-16 12:00 |
00:29:35.16 |
-05:25:33.7 |
HIP 2298 |
13.09 |
| 2026-05-17 00:00 |
00:30:02.40 |
-05:23:12.4 |
HIP 2298 |
18.31 |
| 2026-05-17 12:00 |
00:30:29.57 |
-05:20:51.8 |
HIP 2515 |
21.59 |
| 2026-05-18 00:00 |
00:30:56.67 |
-05:18:31.9 |
HIP 2515 |
14.50 |
| 2026-05-18 12:00 |
00:31:23.72 |
-05:16:12.8 |
HIP 2515 |
7.51 |
| 2026-05-19 00:00 |
00:31:50.70 |
-05:13:54.5 |
HIP 2515 |
1.96 |
| 2026-05-19 12:00 |
00:32:17.61 |
-05:11:36.9 |
HIP 2533 |
2.53 |
| 2026-05-20 00:00 |
00:32:44.45 |
-05:09:20.0 |
HIP 2533 |
9.16 |
| 2026-05-20 12:00 |
00:33:11.23 |
-05:07:04.0 |
HIP 2533 |
16.14 |
| 2026-05-21 00:00 |
00:33:37.94 |
-05:04:48.7 |
HIP 2533 |
23.14 |
| 2026-05-21 12:00 |
00:34:04.58 |
-05:02:34.1 |
HIP 2836 |
28.20 |
| 2026-05-22 00:00 |
00:34:31.15 |
-05:00:20.4 |
HIP 2836 |
21.76 |
| 2026-05-22 12:00 |
00:34:57.66 |
-04:58:07.4 |
HIP 2836 |
15.80 |
| 2026-05-23 00:00 |
00:35:24.09 |
-04:55:55.3 |
HIP 2836 |
11.08 |
| 2026-05-23 12:00 |
00:35:50.45 |
-04:53:43.9 |
HIP 2836 |
9.60 |
| 2026-05-24 00:00 |
00:36:16.73 |
-04:51:33.3 |
HIP 2836 |
12.53 |
| 2026-05-24 12:00 |
00:36:42.95 |
-04:49:23.6 |
HIP 2836 |
17.78 |
| 2026-05-25 00:00 |
00:37:09.09 |
-04:47:14.6 |
HIP 2836 |
23.85 |
| 2026-05-25 12:00 |
00:37:35.16 |
-04:45:06.5 |
HIP 2836 |
30.23 |
| 2026-05-26 00:00 |
00:38:01.15 |
-04:42:59.2 |
HIP 2836 |
36.76 |
| 2026-05-26 12:00 |
00:38:27.07 |
-04:40:52.7 |
HIP 3222 |
37.99 |
| 2026-05-27 00:00 |
00:38:52.91 |
-04:38:47.0 |
HIP 3222 |
31.29 |
| 2026-05-27 12:00 |
00:39:18.68 |
-04:36:42.2 |
HIP 3222 |
24.65 |
| 2026-05-28 00:00 |
00:39:44.36 |
-04:34:38.2 |
HIP 3222 |
18.10 |
| 2026-05-28 12:00 |
00:40:09.97 |
-04:32:35.0 |
HIP 3222 |
11.78 |
| 2026-05-29 00:00 |
00:40:35.51 |
-04:30:32.8 |
HIP 3222 |
6.31 |
| 2026-05-29 12:00 |
00:41:00.96 |
-04:28:31.3 |
HIP 3222 |
5.47 |
| 2026-05-30 00:00 |
00:41:26.33 |
-04:26:30.7 |
HIP 3222 |
10.40 |
| 2026-05-30 12:00 |
00:41:51.62 |
-04:24:31.0 |
HIP 3260 |
11.79 |
| 2026-05-31 00:00 |
00:42:16.83 |
-04:22:32.2 |
HIP 3260 |
14.38 |
| 2026-05-31 12:00 |
00:42:41.95 |
-04:20:34.2 |
HIP 3260 |
19.00 |
| 2026-06-01 00:00 |
00:43:07.00 |
-04:18:37.1 |
HIP 3465 |
18.86 |
| 2026-06-01 12:00 |
00:43:31.96 |
-04:16:40.9 |
HIP 3465 |
13.92 |
| 2026-06-02 00:00 |
00:43:56.83 |
-04:14:45.6 |
HIP 3465 |
10.79 |