C/2003 K1 (Spacewatch)
| Parameter |
Value |
| Designation |
C/2003 K1 (Spacewatch) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2002-12-21T03:39:15.825600Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:30Z |
| Obs used |
52 |
| NEO |
- |
| M1 |
14.100 |
| K1 |
8.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2003-05-30.0000000 |
| e |
0.95010346 |
| q (au) |
2.087130 |
| a (au) |
41.829157 |
| i (deg) |
129.831395 |
| Ω (om, deg) |
250.055839 |
| ω (w, deg) |
314.475766 |
| M (ma, deg) |
0.582360 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.875 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.875 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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) |
| 2026-02-03 00:00 |
09:48:15.23 |
+62:04:19.9 |
HIP 47774 |
32.88 |
| 2026-02-03 12:00 |
09:48:08.57 |
+62:04:37.1 |
HIP 47774 |
32.08 |
| 2026-02-04 00:00 |
09:48:01.90 |
+62:04:54.0 |
HIP 47774 |
31.28 |
| 2026-02-04 12:00 |
09:47:55.21 |
+62:05:10.6 |
HIP 47774 |
30.49 |
| 2026-02-05 00:00 |
09:47:48.52 |
+62:05:26.9 |
HIP 47774 |
29.70 |
| 2026-02-05 12:00 |
09:47:41.81 |
+62:05:42.9 |
HIP 47774 |
28.92 |
| 2026-02-06 00:00 |
09:47:35.10 |
+62:05:58.5 |
HIP 47774 |
28.14 |
| 2026-02-06 12:00 |
09:47:28.37 |
+62:06:13.9 |
HIP 47774 |
27.37 |
| 2026-02-07 00:00 |
09:47:21.64 |
+62:06:28.9 |
HIP 47774 |
26.60 |
| 2026-02-07 12:00 |
09:47:14.90 |
+62:06:43.6 |
HIP 47774 |
25.84 |
| 2026-02-08 00:00 |
09:47:08.16 |
+62:06:57.9 |
HIP 47774 |
25.08 |
| 2026-02-08 12:00 |
09:47:01.41 |
+62:07:12.0 |
HIP 47774 |
24.33 |
| 2026-02-09 00:00 |
09:46:54.65 |
+62:07:25.7 |
HIP 47774 |
23.59 |
| 2026-02-09 12:00 |
09:46:47.89 |
+62:07:39.1 |
HIP 47774 |
22.86 |
| 2026-02-10 00:00 |
09:46:41.12 |
+62:07:52.2 |
HIP 47774 |
22.14 |
| 2026-02-10 12:00 |
09:46:34.35 |
+62:08:04.9 |
HIP 47774 |
21.43 |
| 2026-02-11 00:00 |
09:46:27.57 |
+62:08:17.3 |
HIP 47774 |
20.73 |
| 2026-02-11 12:00 |
09:46:20.79 |
+62:08:29.4 |
HIP 47774 |
20.05 |
| 2026-02-12 00:00 |
09:46:14.01 |
+62:08:41.1 |
HIP 47774 |
19.38 |
| 2026-02-12 12:00 |
09:46:07.23 |
+62:08:52.5 |
HIP 47774 |
18.72 |
| 2026-02-13 00:00 |
09:46:00.44 |
+62:09:03.6 |
HIP 47774 |
18.08 |
| 2026-02-13 12:00 |
09:45:53.66 |
+62:09:14.3 |
HIP 47774 |
17.46 |
| 2026-02-14 00:00 |
09:45:46.87 |
+62:09:24.7 |
HIP 47774 |
16.86 |
| 2026-02-14 12:00 |
09:45:40.09 |
+62:09:34.7 |
HIP 47774 |
16.29 |
| 2026-02-15 00:00 |
09:45:33.31 |
+62:09:44.5 |
HIP 47774 |
15.73 |
| 2026-02-15 12:00 |
09:45:26.53 |
+62:09:53.9 |
HIP 47774 |
15.21 |
| 2026-02-16 00:00 |
09:45:19.75 |
+62:10:02.9 |
HIP 47774 |
14.72 |
| 2026-02-16 12:00 |
09:45:12.97 |
+62:10:11.6 |
HIP 47774 |
14.26 |
| 2026-02-17 00:00 |
09:45:06.20 |
+62:10:20.0 |
HIP 47774 |
13.84 |
| 2026-02-17 12:00 |
09:44:59.43 |
+62:10:28.0 |
HIP 47774 |
13.45 |
| 2026-02-18 00:00 |
09:44:52.67 |
+62:10:35.7 |
HIP 47774 |
13.11 |
| 2026-02-18 12:00 |
09:44:45.91 |
+62:10:43.0 |
HIP 47774 |
12.82 |
| 2026-02-19 00:00 |
09:44:39.16 |
+62:10:50.0 |
HIP 47774 |
12.58 |
| 2026-02-19 12:00 |
09:44:32.42 |
+62:10:56.7 |
HIP 47774 |
12.39 |
| 2026-02-20 00:00 |
09:44:25.68 |
+62:11:03.0 |
HIP 47774 |
12.25 |
| 2026-02-20 12:00 |
09:44:18.95 |
+62:11:08.9 |
HIP 47774 |
12.17 |
| 2026-02-21 00:00 |
09:44:12.23 |
+62:11:14.6 |
HIP 47774 |
12.14 |
| 2026-02-21 12:00 |
09:44:05.52 |
+62:11:19.8 |
HIP 47774 |
12.17 |
| 2026-02-22 00:00 |
09:43:58.82 |
+62:11:24.8 |
HIP 47774 |
12.26 |
| 2026-02-22 12:00 |
09:43:52.13 |
+62:11:29.4 |
HIP 47774 |
12.40 |
| 2026-02-23 00:00 |
09:43:45.44 |
+62:11:33.6 |
HIP 47774 |
12.59 |
| 2026-02-23 12:00 |
09:43:38.78 |
+62:11:37.5 |
HIP 47774 |
12.83 |
| 2026-02-24 00:00 |
09:43:32.12 |
+62:11:41.1 |
HIP 47774 |
13.12 |