| Parameter |
Value |
| Designation |
C/1898 U1 (Brooks) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1898-11-23T15:38:33.040320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:55Z |
| Obs used |
60 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1898-11-05.0000000 |
| e |
1.00000000 |
| q (au) |
0.756018 |
| a (au) |
- |
| i (deg) |
140.344759 |
| Ω (om, deg) |
97.741144 |
| ω (w, deg) |
123.548388 |
| M (ma, deg) |
- |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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 |
09:38:16.61 |
-23:11:59.5 |
HIP 47372 |
12.98 |
| 2026-07-29 12:00 |
09:38:17.42 |
-23:12:00.4 |
HIP 47372 |
12.83 |
| 2026-07-30 00:00 |
09:38:18.23 |
-23:12:01.4 |
HIP 47372 |
12.68 |
| 2026-07-30 12:00 |
09:38:19.04 |
-23:12:02.5 |
HIP 47372 |
12.52 |
| 2026-07-31 00:00 |
09:38:19.85 |
-23:12:03.6 |
HIP 47372 |
12.37 |
| 2026-07-31 12:00 |
09:38:20.66 |
-23:12:04.8 |
HIP 47372 |
12.22 |
| 2026-08-01 00:00 |
09:38:21.48 |
-23:12:06.0 |
HIP 47372 |
12.07 |
| 2026-08-01 12:00 |
09:38:22.29 |
-23:12:07.3 |
HIP 47372 |
11.93 |
| 2026-08-02 00:00 |
09:38:23.11 |
-23:12:08.7 |
HIP 47372 |
11.78 |
| 2026-08-02 12:00 |
09:38:23.93 |
-23:12:10.2 |
HIP 47372 |
11.64 |
| 2026-08-03 00:00 |
09:38:24.75 |
-23:12:11.7 |
HIP 47372 |
11.50 |
| 2026-08-03 12:00 |
09:38:25.57 |
-23:12:13.3 |
HIP 47372 |
11.36 |
| 2026-08-04 00:00 |
09:38:26.40 |
-23:12:15.0 |
HIP 47372 |
11.22 |
| 2026-08-04 12:00 |
09:38:27.22 |
-23:12:16.7 |
HIP 47372 |
11.08 |
| 2026-08-05 00:00 |
09:38:28.05 |
-23:12:18.5 |
HIP 47372 |
10.95 |
| 2026-08-05 12:00 |
09:38:28.88 |
-23:12:20.3 |
HIP 47372 |
10.81 |
| 2026-08-06 00:00 |
09:38:29.71 |
-23:12:22.3 |
HIP 47372 |
10.68 |
| 2026-08-06 12:00 |
09:38:30.54 |
-23:12:24.2 |
HIP 47372 |
10.56 |
| 2026-08-07 00:00 |
09:38:31.37 |
-23:12:26.3 |
HIP 47372 |
10.43 |
| 2026-08-07 12:00 |
09:38:32.20 |
-23:12:28.4 |
HIP 47372 |
10.31 |
| 2026-08-08 00:00 |
09:38:33.03 |
-23:12:30.6 |
HIP 47372 |
10.19 |
| 2026-08-08 12:00 |
09:38:33.87 |
-23:12:32.9 |
HIP 47372 |
10.07 |
| 2026-08-09 00:00 |
09:38:34.70 |
-23:12:35.2 |
HIP 47372 |
9.96 |
| 2026-08-09 12:00 |
09:38:35.54 |
-23:12:37.6 |
HIP 47372 |
9.85 |
| 2026-08-10 00:00 |
09:38:36.37 |
-23:12:40.0 |
HIP 47372 |
9.74 |
| 2026-08-10 12:00 |
09:38:37.21 |
-23:12:42.5 |
HIP 47372 |
9.64 |
| 2026-08-11 00:00 |
09:38:38.05 |
-23:12:45.1 |
HIP 47372 |
9.54 |
| 2026-08-11 12:00 |
09:38:38.89 |
-23:12:47.8 |
HIP 47372 |
9.45 |
| 2026-08-12 00:00 |
09:38:39.72 |
-23:12:50.5 |
HIP 47372 |
9.35 |
| 2026-08-12 12:00 |
09:38:40.56 |
-23:12:53.3 |
HIP 47372 |
9.27 |
| 2026-08-13 00:00 |
09:38:41.40 |
-23:12:56.1 |
HIP 47372 |
9.18 |
| 2026-08-13 12:00 |
09:38:42.24 |
-23:12:59.0 |
HIP 47372 |
9.10 |
| 2026-08-14 00:00 |
09:38:43.08 |
-23:13:02.0 |
HIP 47372 |
9.03 |
| 2026-08-14 12:00 |
09:38:43.92 |
-23:13:05.0 |
HIP 47372 |
8.96 |
| 2026-08-15 00:00 |
09:38:44.76 |
-23:13:08.1 |
HIP 47372 |
8.89 |
| 2026-08-15 12:00 |
09:38:45.60 |
-23:13:11.3 |
HIP 47372 |
8.83 |
| 2026-08-16 00:00 |
09:38:46.44 |
-23:13:14.5 |
HIP 47372 |
8.78 |
| 2026-08-16 12:00 |
09:38:47.28 |
-23:13:17.8 |
HIP 47372 |
8.73 |
| 2026-08-17 00:00 |
09:38:48.12 |
-23:13:21.2 |
HIP 47372 |
8.68 |
| 2026-08-17 12:00 |
09:38:48.96 |
-23:13:24.6 |
HIP 47372 |
8.65 |
| 2026-08-18 00:00 |
09:38:49.80 |
-23:13:28.0 |
HIP 47372 |
8.61 |
| 2026-08-18 12:00 |
09:38:50.64 |
-23:13:31.6 |
HIP 47372 |
8.58 |
| 2026-08-19 00:00 |
09:38:51.48 |
-23:13:35.2 |
HIP 47372 |
8.56 |