C/2026 A1 (MAPS)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2026 A1 (MAPS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2026-04-04T14:23:36.196800Z |
| Orbit solution date (soln_date, UTC) | 2026-03-31T09:42:27Z |
| Obs used | 461 |
| NEO | - |
| M1 | 14.800 |
| K1 | 14.500 |
| PC | - |
| Discovery observation (MPC, UTC) | 2026-01-13T03:38:48.480000Z |
| Discovery magnitude (MPC) | 17.80 G |
| Discovery observatory (MPC) | W94 · MAPS, San Pedro de Atacama |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2026-02-12.0000000 |
| e | 0.99996265 |
| q (au) | 0.005729 |
| a (au) | 153.386972 |
| i (deg) | 144.493667 |
| Ω (om, deg) | 7.865011 |
| ω (w, deg) | 86.324633 |
| M (ma, deg) | 359.973229 |
Magnitude
Scatter + Global Linear
$$ M_a = (12.335 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 12.335 |
| n | 6.000 |
| 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 |
|---|---|---|---|
| 2026-01-13 | 2026-03-16 | +3.4140 | -0.813 |
| 2026-03-16 | 2026-03-29 | -5.0595 | -1.247 |
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) |
|---|---|---|---|---|
| 2026-03-26 00:00 | 01:55:45.45 | -03:11:18.1 | HIP 9005 | 6.51 |
| 2026-03-26 12:00 | 01:54:06.67 | -02:50:54.4 | HIP 8720 | 29.12 |
| 2026-03-27 00:00 | 01:52:24.24 | -02:30:11.6 | HIP 8661 | 14.43 |
| 2026-03-27 12:00 | 01:50:37.80 | -02:09:08.2 | HIP 8580 | 5.40 |
| 2026-03-28 00:00 | 01:48:46.95 | -01:47:42.4 | HIP 8425 | 15.97 |
| 2026-03-28 12:00 | 01:46:51.21 | -01:25:52.2 | HIP 8425 | 27.57 |
| 2026-03-29 00:00 | 01:44:50.06 | -01:03:35.4 | HIP 8161 | 2.24 |
| 2026-03-29 12:00 | 01:42:42.84 | -00:40:49.4 | HIP 8053 | 11.87 |
| 2026-03-30 00:00 | 01:40:28.82 | -00:17:31.0 | HIP 7779 | 6.21 |
| 2026-03-30 12:00 | 01:38:07.05 | +00:06:23.5 | HIP 7549 | 30.21 |
| 2026-03-31 00:00 | 01:35:36.44 | +00:30:58.6 | HIP 7341 | 22.93 |
| 2026-03-31 12:00 | 01:32:55.56 | +00:56:20.0 | HIP 7149 | 26.92 |
| 2026-04-01 00:00 | 01:30:02.60 | +01:22:34.8 | HIP 7025 | 7.28 |
| 2026-04-01 12:00 | 01:26:55.14 | +01:49:52.5 | HIP 6777 | 18.17 |
| 2026-04-02 00:00 | 01:23:29.87 | +02:18:26.1 | HIP 6459 | 19.95 |
| 2026-04-02 12:00 | 01:19:41.89 | +02:48:34.7 | HIP 6263 | 21.52 |
| 2026-04-03 00:00 | 01:15:23.49 | +03:20:48.3 | HIP 5821 | 28.42 |
| 2026-04-03 12:00 | 01:10:20.93 | +03:56:01.1 | HIP 5573 | 34.11 |
| 2026-04-04 00:00 | 01:04:03.75 | +04:36:14.8 | HIP 5023 | 23.06 |
| 2026-04-04 12:00 | 00:54:34.31 | +05:29:59.0 | HIP 4325 | 14.33 |
| 2026-04-05 00:00 | 01:05:04.50 | +05:24:28.3 | HIP 5074 | 15.20 |
| 2026-04-05 12:00 | 01:17:08.95 | +05:04:02.9 | HIP 5969 | 6.14 |
| 2026-04-06 00:00 | 01:27:25.42 | +04:48:09.7 | HIP 6800 | 20.47 |
| 2026-04-06 12:00 | 01:36:41.81 | +04:34:46.4 | HIP 7476 | 17.08 |
| 2026-04-07 00:00 | 01:45:16.43 | +04:23:04.2 | HIP 8051 | 29.15 |
| 2026-04-07 12:00 | 01:53:18.76 | +04:12:37.2 | HIP 8668 | 25.42 |
| 2026-04-08 00:00 | 02:00:54.52 | +04:03:09.8 | HIP 9410 | 2.03 |
| 2026-04-08 12:00 | 02:08:07.51 | +03:54:31.4 | HIP 9854 | 20.19 |
| 2026-04-09 00:00 | 02:15:00.45 | +03:46:34.6 | HIP 10480 | 4.87 |
| 2026-04-09 12:00 | 02:21:35.40 | +03:39:13.7 | HIP 11117 | 22.94 |
| 2026-04-10 00:00 | 02:27:53.96 | +03:32:24.4 | HIP 11538 | 12.80 |
| 2026-04-10 12:00 | 02:33:57.46 | +03:26:03.2 | HIP 11815 | 23.75 |
| 2026-04-11 00:00 | 02:39:46.97 | +03:20:07.2 | HIP 12503 | 17.34 |
| 2026-04-11 12:00 | 02:45:23.46 | +03:14:34.1 | HIP 12946 | 17.14 |
| 2026-04-12 00:00 | 02:50:47.73 | +03:09:21.8 | HIP 13314 | 10.18 |
| 2026-04-12 12:00 | 02:56:00.52 | +03:04:28.4 | HIP 13572 | 26.30 |
| 2026-04-13 00:00 | 03:01:02.47 | +02:59:52.4 | HIP 14014 | 10.92 |
| 2026-04-13 12:00 | 03:05:54.18 | +02:55:32.5 | HIP 14348 | 12.87 |
| 2026-04-14 00:00 | 03:10:36.19 | +02:51:27.4 | HIP 14704 | 15.67 |
| 2026-04-14 12:00 | 03:15:08.99 | +02:47:36.0 | HIP 15090 | 8.44 |
| 2026-04-15 00:00 | 03:19:33.06 | +02:43:57.3 | HIP 15467 | 1.46 |
| 2026-04-15 12:00 | 03:23:48.80 | +02:40:30.3 | HIP 15779 | 12.63 |
| 2026-04-16 00:00 | 03:27:56.63 | +02:37:14.2 | HIP 16086 | 23.05 |