C/2023 U1 (Fuls)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2023 U1 (Fuls) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2024-10-12T19:51:42.851520Z |
| Orbit solution date (soln_date, UTC) | 2026-01-07T15:42:42Z |
| Obs used | 641 |
| NEO | - |
| M1 | 9.900 |
| K1 | 6.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2023-10-16T11:27:03.686400Z |
| Discovery magnitude (MPC) | 19.34 G |
| Discovery observatory (MPC) | G96 · University of Arizona Mt. Lemmon Survey |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2025-02-02.0000000 |
| e | 0.99787289 |
| q (au) | 4.972919 |
| a (au) | 2337.878590 |
| i (deg) | 108.145664 |
| Ω (om, deg) | 305.805991 |
| ω (w, deg) | 255.633994 |
| M (ma, deg) | 0.000978 |
Magnitude
Scatter + Global Linear
$$ M_a = (10.038 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 10.038 |
| n | 2.000 |
| gf | 1.000 |
| gb | -0.500 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) | End (UTC) | a | b |
|---|---|---|---|
| 2023-01-14 | 2024-10-05 | +10.8460 | -6.986 |
| 2024-10-21 | 2025-12-30 | -4.0607 | +2.693 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Finding Chart
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-06-01 00:00 | 23:48:37.44 | -48:13:55.3 | HIP 117320 | 12.96 |
| 2026-06-01 12:00 | 23:48:32.12 | -48:15:51.1 | HIP 117320 | 11.83 |
| 2026-06-02 00:00 | 23:48:26.59 | -48:17:48.1 | HIP 117320 | 10.96 |
| 2026-06-02 12:00 | 23:48:20.85 | -48:19:46.3 | HIP 117320 | 10.45 |
| 2026-06-03 00:00 | 23:48:14.89 | -48:21:45.7 | HIP 117320 | 10.36 |
| 2026-06-03 12:00 | 23:48:08.71 | -48:23:46.2 | HIP 117320 | 10.73 |
| 2026-06-04 00:00 | 23:48:02.32 | -48:25:47.8 | HIP 117320 | 11.54 |
| 2026-06-04 12:00 | 23:47:55.70 | -48:27:50.6 | HIP 117320 | 12.71 |
| 2026-06-05 00:00 | 23:47:48.86 | -48:29:54.5 | HIP 117320 | 14.17 |
| 2026-06-05 12:00 | 23:47:41.80 | -48:31:59.5 | HIP 117320 | 15.86 |
| 2026-06-06 00:00 | 23:47:34.52 | -48:34:05.6 | HIP 117320 | 17.73 |
| 2026-06-06 12:00 | 23:47:27.01 | -48:36:12.8 | HIP 117187 | 18.65 |
| 2026-06-07 00:00 | 23:47:19.27 | -48:38:21.0 | HIP 117187 | 16.99 |
| 2026-06-07 12:00 | 23:47:11.30 | -48:40:30.3 | HIP 117187 | 15.51 |
| 2026-06-08 00:00 | 23:47:03.11 | -48:42:40.6 | HIP 117187 | 14.30 |
| 2026-06-08 12:00 | 23:46:54.68 | -48:44:52.0 | HIP 117250 | 13.21 |
| 2026-06-09 00:00 | 23:46:46.02 | -48:47:04.3 | HIP 117250 | 10.71 |
| 2026-06-09 12:00 | 23:46:37.13 | -48:49:17.7 | HIP 117250 | 8.26 |
| 2026-06-10 00:00 | 23:46:28.00 | -48:51:32.0 | HIP 117250 | 5.98 |
| 2026-06-10 12:00 | 23:46:18.64 | -48:53:47.3 | HIP 117250 | 4.23 |
| 2026-06-11 00:00 | 23:46:09.03 | -48:56:03.6 | HIP 117250 | 3.89 |
| 2026-06-11 12:00 | 23:45:59.19 | -48:58:20.7 | HIP 117250 | 5.30 |
| 2026-06-12 00:00 | 23:45:49.11 | -49:00:38.8 | HIP 117250 | 7.57 |
| 2026-06-12 12:00 | 23:45:38.78 | -49:02:57.8 | HIP 117250 | 10.17 |
| 2026-06-13 00:00 | 23:45:28.21 | -49:05:17.7 | HIP 117250 | 12.92 |
| 2026-06-13 12:00 | 23:45:17.40 | -49:07:38.5 | HIP 117250 | 15.77 |
| 2026-06-14 00:00 | 23:45:06.34 | -49:10:00.1 | HIP 117250 | 18.68 |
| 2026-06-14 12:00 | 23:44:55.03 | -49:12:22.5 | HIP 117250 | 21.65 |
| 2026-06-15 00:00 | 23:44:43.47 | -49:14:45.7 | HIP 117250 | 24.66 |
| 2026-06-15 12:00 | 23:44:31.66 | -49:17:09.7 | HIP 117250 | 27.72 |
| 2026-06-16 00:00 | 23:44:19.61 | -49:19:34.5 | HIP 117250 | 30.82 |
| 2026-06-16 12:00 | 23:44:07.30 | -49:22:00.0 | HIP 117250 | 33.96 |
| 2026-06-17 00:00 | 23:43:54.73 | -49:24:26.3 | HIP 116813 | 35.77 |
| 2026-06-17 12:00 | 23:43:41.92 | -49:26:53.3 | HIP 116813 | 34.81 |
| 2026-06-18 00:00 | 23:43:28.84 | -49:29:20.9 | HIP 116813 | 34.10 |
| 2026-06-18 12:00 | 23:43:15.52 | -49:31:49.2 | HIP 116813 | 33.66 |
| 2026-06-19 00:00 | 23:43:01.93 | -49:34:18.2 | HIP 116813 | 33.53 |
| 2026-06-19 12:00 | 23:42:48.09 | -49:36:47.7 | HIP 116813 | 33.70 |
| 2026-06-20 00:00 | 23:42:33.99 | -49:39:17.9 | HIP 116813 | 34.19 |
| 2026-06-20 12:00 | 23:42:19.63 | -49:41:48.7 | HIP 116919 | 34.22 |
| 2026-06-21 00:00 | 23:42:05.00 | -49:44:20.0 | HIP 116919 | 31.53 |
| 2026-06-21 12:00 | 23:41:50.12 | -49:46:51.8 | HIP 116919 | 28.99 |
| 2026-06-22 00:00 | 23:41:34.98 | -49:49:24.1 | HIP 116919 | 26.66 |