| 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) |
| 2026-03-26 00:00 |
09:37:38.88 |
-23:35:08.5 |
HIP 47365 |
31.55 |
| 2026-03-26 12:00 |
09:37:38.23 |
-23:35:00.8 |
HIP 47365 |
31.74 |
| 2026-03-27 00:00 |
09:37:37.59 |
-23:34:53.1 |
HIP 47365 |
31.93 |
| 2026-03-27 12:00 |
09:37:36.95 |
-23:34:45.3 |
HIP 47365 |
32.13 |
| 2026-03-28 00:00 |
09:37:36.31 |
-23:34:37.5 |
HIP 47365 |
32.32 |
| 2026-03-28 12:00 |
09:37:35.68 |
-23:34:29.7 |
HIP 47365 |
32.51 |
| 2026-03-29 00:00 |
09:37:35.06 |
-23:34:21.9 |
HIP 47365 |
32.70 |
| 2026-03-29 12:00 |
09:37:34.44 |
-23:34:14.0 |
HIP 47365 |
32.89 |
| 2026-03-30 00:00 |
09:37:33.83 |
-23:34:06.2 |
HIP 47365 |
33.08 |
| 2026-03-30 12:00 |
09:37:33.22 |
-23:33:58.3 |
HIP 47365 |
33.27 |
| 2026-03-31 00:00 |
09:37:32.62 |
-23:33:50.3 |
HIP 47365 |
33.46 |
| 2026-03-31 12:00 |
09:37:32.02 |
-23:33:42.4 |
HIP 47365 |
33.65 |
| 2026-04-01 00:00 |
09:37:31.43 |
-23:33:34.4 |
HIP 47365 |
33.83 |
| 2026-04-01 12:00 |
09:37:30.85 |
-23:33:26.4 |
HIP 47365 |
34.02 |
| 2026-04-02 00:00 |
09:37:30.27 |
-23:33:18.4 |
HIP 47365 |
34.21 |
| 2026-04-02 12:00 |
09:37:29.70 |
-23:33:10.3 |
HIP 47365 |
34.39 |
| 2026-04-03 00:00 |
09:37:29.13 |
-23:33:02.3 |
HIP 47365 |
34.58 |
| 2026-04-03 12:00 |
09:37:28.57 |
-23:32:54.2 |
HIP 47365 |
34.77 |
| 2026-04-04 00:00 |
09:37:28.01 |
-23:32:46.1 |
HIP 47365 |
34.95 |
| 2026-04-04 12:00 |
09:37:27.46 |
-23:32:38.0 |
HIP 47365 |
35.14 |
| 2026-04-05 00:00 |
09:37:26.92 |
-23:32:29.9 |
HIP 47372 |
35.15 |
| 2026-04-05 12:00 |
09:37:26.38 |
-23:32:21.7 |
HIP 47372 |
35.13 |
| 2026-04-06 00:00 |
09:37:25.85 |
-23:32:13.5 |
HIP 47372 |
35.10 |
| 2026-04-06 12:00 |
09:37:25.32 |
-23:32:05.3 |
HIP 47372 |
35.08 |
| 2026-04-07 00:00 |
09:37:24.80 |
-23:31:57.1 |
HIP 47372 |
35.06 |
| 2026-04-07 12:00 |
09:37:24.29 |
-23:31:48.9 |
HIP 47372 |
35.03 |
| 2026-04-08 00:00 |
09:37:23.78 |
-23:31:40.7 |
HIP 47372 |
35.01 |
| 2026-04-08 12:00 |
09:37:23.28 |
-23:31:32.4 |
HIP 47372 |
34.99 |
| 2026-04-09 00:00 |
09:37:22.78 |
-23:31:24.2 |
HIP 47372 |
34.96 |
| 2026-04-09 12:00 |
09:37:22.29 |
-23:31:15.9 |
HIP 47372 |
34.94 |
| 2026-04-10 00:00 |
09:37:21.81 |
-23:31:07.6 |
HIP 47372 |
34.91 |
| 2026-04-10 12:00 |
09:37:21.34 |
-23:30:59.3 |
HIP 47372 |
34.89 |
| 2026-04-11 00:00 |
09:37:20.87 |
-23:30:51.0 |
HIP 47372 |
34.86 |
| 2026-04-11 12:00 |
09:37:20.40 |
-23:30:42.7 |
HIP 47372 |
34.84 |
| 2026-04-12 00:00 |
09:37:19.95 |
-23:30:34.4 |
HIP 47372 |
34.81 |
| 2026-04-12 12:00 |
09:37:19.49 |
-23:30:26.0 |
HIP 47372 |
34.78 |
| 2026-04-13 00:00 |
09:37:19.05 |
-23:30:17.7 |
HIP 47372 |
34.76 |
| 2026-04-13 12:00 |
09:37:18.61 |
-23:30:09.3 |
HIP 47372 |
34.73 |
| 2026-04-14 00:00 |
09:37:18.18 |
-23:30:00.9 |
HIP 47372 |
34.70 |
| 2026-04-14 12:00 |
09:37:17.76 |
-23:29:52.6 |
HIP 47372 |
34.67 |
| 2026-04-15 00:00 |
09:37:17.34 |
-23:29:44.2 |
HIP 47372 |
34.65 |
| 2026-04-15 12:00 |
09:37:16.93 |
-23:29:35.8 |
HIP 47372 |
34.62 |
| 2026-04-16 00:00 |
09:37:16.52 |
-23:29:27.4 |
HIP 47372 |
34.59 |