| 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) |
| 2026-05-12 00:00 |
09:37:05.17 |
-23:22:20.7 |
HIP 47372 |
32.37 |
| 2026-05-12 12:00 |
09:37:05.15 |
-23:22:12.9 |
HIP 47372 |
32.31 |
| 2026-05-13 00:00 |
09:37:05.13 |
-23:22:05.2 |
HIP 47372 |
32.25 |
| 2026-05-13 12:00 |
09:37:05.11 |
-23:21:57.5 |
HIP 47372 |
32.18 |
| 2026-05-14 00:00 |
09:37:05.11 |
-23:21:49.8 |
HIP 47372 |
32.12 |
| 2026-05-14 12:00 |
09:37:05.11 |
-23:21:42.2 |
HIP 47372 |
32.06 |
| 2026-05-15 00:00 |
09:37:05.12 |
-23:21:34.6 |
HIP 47372 |
31.99 |
| 2026-05-15 12:00 |
09:37:05.14 |
-23:21:27.0 |
HIP 47372 |
31.93 |
| 2026-05-16 00:00 |
09:37:05.16 |
-23:21:19.4 |
HIP 47372 |
31.86 |
| 2026-05-16 12:00 |
09:37:05.19 |
-23:21:11.9 |
HIP 47372 |
31.79 |
| 2026-05-17 00:00 |
09:37:05.23 |
-23:21:04.4 |
HIP 47372 |
31.72 |
| 2026-05-17 12:00 |
09:37:05.28 |
-23:20:57.0 |
HIP 47372 |
31.66 |
| 2026-05-18 00:00 |
09:37:05.33 |
-23:20:49.6 |
HIP 47372 |
31.59 |
| 2026-05-18 12:00 |
09:37:05.39 |
-23:20:42.2 |
HIP 47372 |
31.51 |
| 2026-05-19 00:00 |
09:37:05.46 |
-23:20:34.8 |
HIP 47372 |
31.44 |
| 2026-05-19 12:00 |
09:37:05.53 |
-23:20:27.5 |
HIP 47372 |
31.37 |
| 2026-05-20 00:00 |
09:37:05.61 |
-23:20:20.2 |
HIP 47372 |
31.30 |
| 2026-05-20 12:00 |
09:37:05.70 |
-23:20:13.0 |
HIP 47372 |
31.22 |
| 2026-05-21 00:00 |
09:37:05.80 |
-23:20:05.7 |
HIP 47372 |
31.15 |
| 2026-05-21 12:00 |
09:37:05.90 |
-23:19:58.6 |
HIP 47372 |
31.07 |
| 2026-05-22 00:00 |
09:37:06.01 |
-23:19:51.4 |
HIP 47372 |
30.99 |
| 2026-05-22 12:00 |
09:37:06.13 |
-23:19:44.3 |
HIP 47372 |
30.92 |
| 2026-05-23 00:00 |
09:37:06.26 |
-23:19:37.3 |
HIP 47372 |
30.84 |
| 2026-05-23 12:00 |
09:37:06.39 |
-23:19:30.2 |
HIP 47372 |
30.76 |
| 2026-05-24 00:00 |
09:37:06.53 |
-23:19:23.2 |
HIP 47372 |
30.68 |
| 2026-05-24 12:00 |
09:37:06.68 |
-23:19:16.3 |
HIP 47372 |
30.60 |
| 2026-05-25 00:00 |
09:37:06.83 |
-23:19:09.4 |
HIP 47372 |
30.51 |
| 2026-05-25 12:00 |
09:37:06.99 |
-23:19:02.5 |
HIP 47372 |
30.43 |
| 2026-05-26 00:00 |
09:37:07.16 |
-23:18:55.7 |
HIP 47372 |
30.35 |
| 2026-05-26 12:00 |
09:37:07.33 |
-23:18:48.9 |
HIP 47372 |
30.26 |
| 2026-05-27 00:00 |
09:37:07.52 |
-23:18:42.2 |
HIP 47372 |
30.18 |
| 2026-05-27 12:00 |
09:37:07.70 |
-23:18:35.5 |
HIP 47372 |
30.09 |
| 2026-05-28 00:00 |
09:37:07.90 |
-23:18:28.8 |
HIP 47372 |
30.00 |
| 2026-05-28 12:00 |
09:37:08.10 |
-23:18:22.2 |
HIP 47372 |
29.91 |
| 2026-05-29 00:00 |
09:37:08.31 |
-23:18:15.6 |
HIP 47372 |
29.82 |
| 2026-05-29 12:00 |
09:37:08.53 |
-23:18:09.1 |
HIP 47372 |
29.73 |
| 2026-05-30 00:00 |
09:37:08.75 |
-23:18:02.6 |
HIP 47372 |
29.64 |
| 2026-05-30 12:00 |
09:37:08.98 |
-23:17:56.2 |
HIP 47372 |
29.55 |
| 2026-05-31 00:00 |
09:37:09.22 |
-23:17:49.8 |
HIP 47372 |
29.45 |
| 2026-05-31 12:00 |
09:37:09.46 |
-23:17:43.4 |
HIP 47372 |
29.36 |
| 2026-06-01 00:00 |
09:37:09.71 |
-23:17:37.1 |
HIP 47372 |
29.26 |
| 2026-06-01 12:00 |
09:37:09.97 |
-23:17:30.9 |
HIP 47372 |
29.17 |
| 2026-06-02 00:00 |
09:37:10.23 |
-23:17:24.6 |
HIP 47372 |
29.07 |