| 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) |
| 2026-07-29 00:00 |
09:40:38.45 |
+60:06:41.0 |
HIP 47632 |
18.09 |
| 2026-07-29 12:00 |
09:40:43.51 |
+60:06:22.4 |
HIP 47632 |
17.73 |
| 2026-07-30 00:00 |
09:40:48.58 |
+60:06:03.9 |
HIP 47632 |
17.38 |
| 2026-07-30 12:00 |
09:40:53.66 |
+60:05:45.7 |
HIP 47632 |
17.05 |
| 2026-07-31 00:00 |
09:40:58.75 |
+60:05:27.8 |
HIP 47632 |
16.74 |
| 2026-07-31 12:00 |
09:41:03.85 |
+60:05:10.0 |
HIP 47632 |
16.45 |
| 2026-08-01 00:00 |
09:41:08.96 |
+60:04:52.5 |
HIP 47632 |
16.18 |
| 2026-08-01 12:00 |
09:41:14.08 |
+60:04:35.2 |
HIP 47632 |
15.93 |
| 2026-08-02 00:00 |
09:41:19.21 |
+60:04:18.1 |
HIP 47632 |
15.70 |
| 2026-08-02 12:00 |
09:41:24.35 |
+60:04:01.3 |
HIP 47632 |
15.50 |
| 2026-08-03 00:00 |
09:41:29.50 |
+60:03:44.7 |
HIP 47632 |
15.33 |
| 2026-08-03 12:00 |
09:41:34.66 |
+60:03:28.3 |
HIP 47632 |
15.18 |
| 2026-08-04 00:00 |
09:41:39.83 |
+60:03:12.2 |
HIP 47632 |
15.06 |
| 2026-08-04 12:00 |
09:41:45.01 |
+60:02:56.3 |
HIP 47632 |
14.97 |
| 2026-08-05 00:00 |
09:41:50.19 |
+60:02:40.6 |
HIP 47632 |
14.90 |
| 2026-08-05 12:00 |
09:41:55.39 |
+60:02:25.2 |
HIP 47632 |
14.86 |
| 2026-08-06 00:00 |
09:42:00.59 |
+60:02:10.0 |
HIP 47632 |
14.85 |
| 2026-08-06 12:00 |
09:42:05.79 |
+60:01:55.0 |
HIP 47632 |
14.87 |
| 2026-08-07 00:00 |
09:42:11.01 |
+60:01:40.3 |
HIP 47632 |
14.92 |
| 2026-08-07 12:00 |
09:42:16.23 |
+60:01:25.8 |
HIP 47632 |
14.99 |
| 2026-08-08 00:00 |
09:42:21.45 |
+60:01:11.6 |
HIP 47632 |
15.10 |
| 2026-08-08 12:00 |
09:42:26.68 |
+60:00:57.6 |
HIP 47632 |
15.23 |
| 2026-08-09 00:00 |
09:42:31.92 |
+60:00:43.8 |
HIP 47632 |
15.38 |
| 2026-08-09 12:00 |
09:42:37.16 |
+60:00:30.3 |
HIP 47632 |
15.56 |
| 2026-08-10 00:00 |
09:42:42.41 |
+60:00:17.1 |
HIP 47632 |
15.76 |
| 2026-08-10 12:00 |
09:42:47.66 |
+60:00:04.1 |
HIP 47632 |
15.99 |
| 2026-08-11 00:00 |
09:42:52.92 |
+59:59:51.3 |
HIP 47632 |
16.24 |
| 2026-08-11 12:00 |
09:42:58.17 |
+59:59:38.8 |
HIP 47632 |
16.51 |
| 2026-08-12 00:00 |
09:43:03.44 |
+59:59:26.6 |
HIP 47632 |
16.80 |
| 2026-08-12 12:00 |
09:43:08.70 |
+59:59:14.6 |
HIP 47632 |
17.11 |
| 2026-08-13 00:00 |
09:43:13.97 |
+59:59:02.8 |
HIP 47632 |
17.43 |
| 2026-08-13 12:00 |
09:43:19.24 |
+59:58:51.4 |
HIP 47632 |
17.77 |
| 2026-08-14 00:00 |
09:43:24.51 |
+59:58:40.1 |
HIP 47632 |
18.13 |
| 2026-08-14 12:00 |
09:43:29.78 |
+59:58:29.2 |
HIP 47632 |
18.50 |
| 2026-08-15 00:00 |
09:43:35.05 |
+59:58:18.4 |
HIP 47632 |
18.89 |
| 2026-08-15 12:00 |
09:43:40.32 |
+59:58:08.0 |
HIP 47632 |
19.28 |
| 2026-08-16 00:00 |
09:43:45.60 |
+59:57:57.8 |
HIP 47632 |
19.69 |
| 2026-08-16 12:00 |
09:43:50.87 |
+59:57:47.8 |
HIP 47632 |
20.11 |
| 2026-08-17 00:00 |
09:43:56.14 |
+59:57:38.1 |
HIP 47632 |
20.54 |
| 2026-08-17 12:00 |
09:44:01.41 |
+59:57:28.7 |
HIP 47632 |
20.98 |
| 2026-08-18 00:00 |
09:44:06.68 |
+59:57:19.6 |
HIP 47894 |
20.80 |
| 2026-08-18 12:00 |
09:44:11.95 |
+59:57:10.7 |
HIP 47894 |
20.30 |
| 2026-08-19 00:00 |
09:44:17.22 |
+59:57:02.0 |
HIP 47894 |
19.83 |