| 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) |
| 2026-09-20 00:00 |
09:39:41.70 |
-23:19:19.6 |
HIP 47464 |
11.82 |
| 2026-09-20 12:00 |
09:39:42.39 |
-23:19:26.5 |
HIP 47464 |
11.65 |
| 2026-09-21 00:00 |
09:39:43.07 |
-23:19:33.4 |
HIP 47464 |
11.48 |
| 2026-09-21 12:00 |
09:39:43.75 |
-23:19:40.4 |
HIP 47464 |
11.31 |
| 2026-09-22 00:00 |
09:39:44.43 |
-23:19:47.4 |
HIP 47464 |
11.14 |
| 2026-09-22 12:00 |
09:39:45.10 |
-23:19:54.5 |
HIP 47464 |
10.97 |
| 2026-09-23 00:00 |
09:39:45.77 |
-23:20:01.6 |
HIP 47464 |
10.80 |
| 2026-09-23 12:00 |
09:39:46.44 |
-23:20:08.7 |
HIP 47464 |
10.64 |
| 2026-09-24 00:00 |
09:39:47.10 |
-23:20:15.8 |
HIP 47464 |
10.48 |
| 2026-09-24 12:00 |
09:39:47.75 |
-23:20:23.0 |
HIP 47464 |
10.32 |
| 2026-09-25 00:00 |
09:39:48.40 |
-23:20:30.2 |
HIP 47464 |
10.16 |
| 2026-09-25 12:00 |
09:39:49.05 |
-23:20:37.5 |
HIP 47464 |
10.01 |
| 2026-09-26 00:00 |
09:39:49.69 |
-23:20:44.8 |
HIP 47464 |
9.85 |
| 2026-09-26 12:00 |
09:39:50.33 |
-23:20:52.1 |
HIP 47464 |
9.70 |
| 2026-09-27 00:00 |
09:39:50.96 |
-23:20:59.4 |
HIP 47464 |
9.56 |
| 2026-09-27 12:00 |
09:39:51.59 |
-23:21:06.8 |
HIP 47464 |
9.41 |
| 2026-09-28 00:00 |
09:39:52.21 |
-23:21:14.2 |
HIP 47464 |
9.27 |
| 2026-09-28 12:00 |
09:39:52.83 |
-23:21:21.7 |
HIP 47464 |
9.13 |
| 2026-09-29 00:00 |
09:39:53.44 |
-23:21:29.1 |
HIP 47464 |
8.99 |
| 2026-09-29 12:00 |
09:39:54.05 |
-23:21:36.6 |
HIP 47464 |
8.86 |
| 2026-09-30 00:00 |
09:39:54.65 |
-23:21:44.2 |
HIP 47464 |
8.73 |
| 2026-09-30 12:00 |
09:39:55.25 |
-23:21:51.7 |
HIP 47464 |
8.60 |
| 2026-10-01 00:00 |
09:39:55.85 |
-23:21:59.3 |
HIP 47464 |
8.48 |
| 2026-10-01 12:00 |
09:39:56.43 |
-23:22:06.9 |
HIP 47464 |
8.36 |
| 2026-10-02 00:00 |
09:39:57.02 |
-23:22:14.5 |
HIP 47464 |
8.24 |
| 2026-10-02 12:00 |
09:39:57.60 |
-23:22:22.2 |
HIP 47464 |
8.13 |
| 2026-10-03 00:00 |
09:39:58.17 |
-23:22:29.9 |
HIP 47464 |
8.02 |
| 2026-10-03 12:00 |
09:39:58.74 |
-23:22:37.6 |
HIP 47464 |
7.91 |
| 2026-10-04 00:00 |
09:39:59.30 |
-23:22:45.3 |
HIP 47464 |
7.81 |
| 2026-10-04 12:00 |
09:39:59.85 |
-23:22:53.1 |
HIP 47464 |
7.71 |
| 2026-10-05 00:00 |
09:40:00.41 |
-23:23:00.9 |
HIP 47464 |
7.62 |
| 2026-10-05 12:00 |
09:40:00.95 |
-23:23:08.7 |
HIP 47464 |
7.53 |
| 2026-10-06 00:00 |
09:40:01.49 |
-23:23:16.5 |
HIP 47464 |
7.45 |
| 2026-10-06 12:00 |
09:40:02.03 |
-23:23:24.3 |
HIP 47464 |
7.37 |
| 2026-10-07 00:00 |
09:40:02.55 |
-23:23:32.2 |
HIP 47464 |
7.30 |
| 2026-10-07 12:00 |
09:40:03.08 |
-23:23:40.1 |
HIP 47464 |
7.23 |
| 2026-10-08 00:00 |
09:40:03.60 |
-23:23:48.0 |
HIP 47464 |
7.17 |
| 2026-10-08 12:00 |
09:40:04.11 |
-23:23:55.9 |
HIP 47464 |
7.11 |
| 2026-10-09 00:00 |
09:40:04.61 |
-23:24:03.9 |
HIP 47464 |
7.06 |
| 2026-10-09 12:00 |
09:40:05.11 |
-23:24:11.8 |
HIP 47464 |
7.01 |
| 2026-10-10 00:00 |
09:40:05.61 |
-23:24:19.8 |
HIP 47464 |
6.97 |
| 2026-10-10 12:00 |
09:40:06.10 |
-23:24:27.8 |
HIP 47464 |
6.93 |
| 2026-10-11 00:00 |
09:40:06.58 |
-23:24:35.8 |
HIP 47464 |
6.90 |