| Parameter |
Value |
| Designation |
475P/Spacewatch-LINEAR |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2004-09-20T05:48:26.389440Z |
| Orbit solution date (soln_date, UTC) |
2025-06-26T10:13:27Z |
| Obs used |
159 |
| NEO |
- |
| M1 |
7.000 |
| K1 |
15.750 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2023-11-11T05:51:29.030400Z |
| Discovery magnitude (MPC) |
20.80 G |
| Discovery observatory (MPC) |
J04 · ESA Optical Ground Station, Tenerife |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-08-10.0000000 |
| e |
0.43983107 |
| q (au) |
4.088003 |
| a (au) |
7.297804 |
| i (deg) |
14.525819 |
| Ω (om, deg) |
147.492673 |
| ω (w, deg) |
40.536988 |
| M (ma, deg) |
144.019928 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.697 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.697 |
| n |
6.000 |
| gf |
0.999 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
18:32:01.75 |
-09:04:39.5 |
HIP 90867 |
17.73 |
| 2026-05-12 12:00 |
18:31:55.12 |
-09:04:08.5 |
HIP 90867 |
18.54 |
| 2026-05-13 00:00 |
18:31:48.32 |
-09:03:38.0 |
HIP 90867 |
19.47 |
| 2026-05-13 12:00 |
18:31:41.37 |
-09:03:08.1 |
HIP 90867 |
20.51 |
| 2026-05-14 00:00 |
18:31:34.25 |
-09:02:38.8 |
HIP 90867 |
21.66 |
| 2026-05-14 12:00 |
18:31:26.97 |
-09:02:10.1 |
HIP 90867 |
22.90 |
| 2026-05-15 00:00 |
18:31:19.54 |
-09:01:42.0 |
HIP 90867 |
24.24 |
| 2026-05-15 12:00 |
18:31:11.95 |
-09:01:14.6 |
HIP 90867 |
25.65 |
| 2026-05-16 00:00 |
18:31:04.21 |
-09:00:47.7 |
HIP 90867 |
27.15 |
| 2026-05-16 12:00 |
18:30:56.31 |
-09:00:21.5 |
HIP 90633 |
26.27 |
| 2026-05-17 00:00 |
18:30:48.25 |
-08:59:56.0 |
HIP 90633 |
25.08 |
| 2026-05-17 12:00 |
18:30:40.05 |
-08:59:31.0 |
HIP 90633 |
23.97 |
| 2026-05-18 00:00 |
18:30:31.70 |
-08:59:06.7 |
HIP 90633 |
22.96 |
| 2026-05-18 12:00 |
18:30:23.20 |
-08:58:43.1 |
HIP 90633 |
22.07 |
| 2026-05-19 00:00 |
18:30:14.55 |
-08:58:20.1 |
HIP 90633 |
21.34 |
| 2026-05-19 12:00 |
18:30:05.76 |
-08:57:57.7 |
HIP 90633 |
20.79 |
| 2026-05-20 00:00 |
18:29:56.82 |
-08:57:36.0 |
HIP 90633 |
20.44 |
| 2026-05-20 12:00 |
18:29:47.74 |
-08:57:15.0 |
HIP 90633 |
20.31 |
| 2026-05-21 00:00 |
18:29:38.52 |
-08:56:54.7 |
HIP 90633 |
20.42 |
| 2026-05-21 12:00 |
18:29:29.16 |
-08:56:35.0 |
HIP 90633 |
20.78 |
| 2026-05-22 00:00 |
18:29:19.67 |
-08:56:16.0 |
HIP 90633 |
21.39 |
| 2026-05-22 12:00 |
18:29:10.04 |
-08:55:57.7 |
HIP 90633 |
22.23 |
| 2026-05-23 00:00 |
18:29:00.27 |
-08:55:40.0 |
HIP 90600 |
22.26 |
| 2026-05-23 12:00 |
18:28:50.37 |
-08:55:23.1 |
HIP 90600 |
22.49 |
| 2026-05-24 00:00 |
18:28:40.34 |
-08:55:06.8 |
HIP 90436 |
22.76 |
| 2026-05-24 12:00 |
18:28:30.19 |
-08:54:51.2 |
HIP 90436 |
20.24 |
| 2026-05-25 00:00 |
18:28:19.90 |
-08:54:36.4 |
HIP 90436 |
17.68 |
| 2026-05-25 12:00 |
18:28:09.49 |
-08:54:22.2 |
HIP 90436 |
15.10 |
| 2026-05-26 00:00 |
18:27:58.96 |
-08:54:08.7 |
HIP 90436 |
12.49 |
| 2026-05-26 12:00 |
18:27:48.30 |
-08:53:55.9 |
HIP 90436 |
9.85 |
| 2026-05-27 00:00 |
18:27:37.52 |
-08:53:43.9 |
HIP 90436 |
7.19 |
| 2026-05-27 12:00 |
18:27:26.62 |
-08:53:32.5 |
HIP 90436 |
4.50 |
| 2026-05-28 00:00 |
18:27:15.61 |
-08:53:21.8 |
HIP 90436 |
1.82 |
| 2026-05-28 12:00 |
18:27:04.48 |
-08:53:11.9 |
HIP 90436 |
1.15 |
| 2026-05-29 00:00 |
18:26:53.23 |
-08:53:02.7 |
HIP 90436 |
3.84 |
| 2026-05-29 12:00 |
18:26:41.88 |
-08:52:54.2 |
HIP 90436 |
6.63 |
| 2026-05-30 00:00 |
18:26:30.41 |
-08:52:46.4 |
HIP 90436 |
9.46 |
| 2026-05-30 12:00 |
18:26:18.83 |
-08:52:39.4 |
HIP 90436 |
12.32 |
| 2026-05-31 00:00 |
18:26:07.15 |
-08:52:33.0 |
HIP 90436 |
15.21 |
| 2026-05-31 12:00 |
18:25:55.36 |
-08:52:27.4 |
HIP 90436 |
18.12 |
| 2026-06-01 00:00 |
18:25:43.47 |
-08:52:22.6 |
HIP 90436 |
21.06 |
| 2026-06-01 12:00 |
18:25:31.48 |
-08:52:18.4 |
HIP 90436 |
24.02 |
| 2026-06-02 00:00 |
18:25:19.39 |
-08:52:15.0 |
HIP 90135 |
24.95 |