| Parameter |
Value |
| Designation |
C/2023 Q1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2024-12-01T03:06:18.527040Z |
| Orbit solution date (soln_date, UTC) |
2025-09-30T13:39:24Z |
| Obs used |
1450 |
| NEO |
- |
| M1 |
11.200 |
| K1 |
9.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2023-08-20T13:18:30.182400Z |
| Discovery magnitude (MPC) |
22.04 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2024-12-04.0000000 |
| e |
1.00529337 |
| q (au) |
2.575719 |
| a (au) |
-486.593364 |
| i (deg) |
36.643014 |
| Ω (om, deg) |
7.131719 |
| ω (w, deg) |
84.409436 |
| M (ma, deg) |
0.000264 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.831 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.831 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.794 |
| k |
0.800 |
| 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 |
| 2023-07-25 |
2023-11-14 |
+13.9933 |
-9.563 |
| 2023-11-14 |
2024-07-30 |
+1.1915 |
-1.285 |
| 2024-07-30 |
2024-12-01 |
-28.2334 |
+12.220 |
| 2024-12-01 |
2025-05-15 |
+2.7850 |
-1.351 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
11:56:50.16 |
+00:21:35.2 |
HIP 58445 |
34.84 |
| 2026-05-12 12:00 |
11:56:42.73 |
+00:20:52.7 |
HIP 58445 |
36.83 |
| 2026-05-13 00:00 |
11:56:35.48 |
+00:20:09.4 |
HIP 58445 |
38.77 |
| 2026-05-13 12:00 |
11:56:28.39 |
+00:19:25.4 |
HIP 58445 |
40.69 |
| 2026-05-14 00:00 |
11:56:21.48 |
+00:18:40.6 |
HIP 58002 |
40.46 |
| 2026-05-14 12:00 |
11:56:14.74 |
+00:17:55.0 |
HIP 58002 |
39.18 |
| 2026-05-15 00:00 |
11:56:08.17 |
+00:17:08.7 |
HIP 58002 |
37.99 |
| 2026-05-15 12:00 |
11:56:01.77 |
+00:16:21.7 |
HIP 58002 |
36.90 |
| 2026-05-16 00:00 |
11:55:55.55 |
+00:15:33.8 |
HIP 58002 |
35.90 |
| 2026-05-16 12:00 |
11:55:49.50 |
+00:14:45.2 |
HIP 58002 |
35.01 |
| 2026-05-17 00:00 |
11:55:43.62 |
+00:13:55.9 |
HIP 58002 |
34.22 |
| 2026-05-17 12:00 |
11:55:37.91 |
+00:13:05.8 |
HIP 58002 |
33.54 |
| 2026-05-18 00:00 |
11:55:32.37 |
+00:12:14.9 |
HIP 58002 |
32.97 |
| 2026-05-18 12:00 |
11:55:27.01 |
+00:11:23.3 |
HIP 58002 |
32.51 |
| 2026-05-19 00:00 |
11:55:21.82 |
+00:10:30.9 |
HIP 58002 |
32.17 |
| 2026-05-19 12:00 |
11:55:16.80 |
+00:09:37.7 |
HIP 58002 |
31.93 |
| 2026-05-20 00:00 |
11:55:11.95 |
+00:08:43.8 |
HIP 58002 |
31.81 |
| 2026-05-20 12:00 |
11:55:07.28 |
+00:07:49.1 |
HIP 58002 |
31.79 |
| 2026-05-21 00:00 |
11:55:02.77 |
+00:06:53.7 |
HIP 58002 |
31.88 |
| 2026-05-21 12:00 |
11:54:58.44 |
+00:05:57.5 |
HIP 58002 |
32.07 |
| 2026-05-22 00:00 |
11:54:54.27 |
+00:05:00.6 |
HIP 58002 |
32.35 |
| 2026-05-22 12:00 |
11:54:50.28 |
+00:04:02.9 |
HIP 58002 |
32.72 |
| 2026-05-23 00:00 |
11:54:46.45 |
+00:03:04.4 |
HIP 58002 |
33.17 |
| 2026-05-23 12:00 |
11:54:42.80 |
+00:02:05.3 |
HIP 58002 |
33.70 |
| 2026-05-24 00:00 |
11:54:39.31 |
+00:01:05.3 |
HIP 58002 |
34.30 |
| 2026-05-24 12:00 |
11:54:35.99 |
+00:00:04.7 |
HIP 58105 |
34.01 |
| 2026-05-25 00:00 |
11:54:32.84 |
-00:00:56.7 |
HIP 58105 |
33.17 |
| 2026-05-25 12:00 |
11:54:29.85 |
-00:01:58.9 |
HIP 58105 |
32.32 |
| 2026-05-26 00:00 |
11:54:27.03 |
-00:03:01.7 |
HIP 58105 |
31.49 |
| 2026-05-26 12:00 |
11:54:24.38 |
-00:04:05.3 |
HIP 58105 |
30.66 |
| 2026-05-27 00:00 |
11:54:21.90 |
-00:05:09.7 |
HIP 58105 |
29.83 |
| 2026-05-27 12:00 |
11:54:19.57 |
-00:06:14.7 |
HIP 58105 |
29.01 |
| 2026-05-28 00:00 |
11:54:17.42 |
-00:07:20.5 |
HIP 58105 |
28.19 |
| 2026-05-28 12:00 |
11:54:15.42 |
-00:08:27.0 |
HIP 58105 |
27.37 |
| 2026-05-29 00:00 |
11:54:13.59 |
-00:09:34.3 |
HIP 58105 |
26.56 |
| 2026-05-29 12:00 |
11:54:11.92 |
-00:10:42.2 |
HIP 58105 |
25.74 |
| 2026-05-30 00:00 |
11:54:10.42 |
-00:11:50.9 |
HIP 58105 |
24.93 |
| 2026-05-30 12:00 |
11:54:09.08 |
-00:13:00.2 |
HIP 58105 |
24.12 |
| 2026-05-31 00:00 |
11:54:07.89 |
-00:14:10.3 |
HIP 58105 |
23.30 |
| 2026-05-31 12:00 |
11:54:06.87 |
-00:15:21.1 |
HIP 58105 |
22.50 |
| 2026-06-01 00:00 |
11:54:06.01 |
-00:16:32.6 |
HIP 58105 |
21.69 |
| 2026-06-01 12:00 |
11:54:05.31 |
-00:17:44.8 |
HIP 58105 |
20.88 |
| 2026-06-02 00:00 |
11:54:04.76 |
-00:18:57.7 |
HIP 58105 |
20.09 |