| 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) |
| 2026-07-29 00:00 |
12:07:23.56 |
-03:42:29.4 |
HIP 59230 |
25.38 |
| 2026-07-29 12:00 |
12:07:36.39 |
-03:44:43.7 |
HIP 59230 |
21.52 |
| 2026-07-30 00:00 |
12:07:49.29 |
-03:46:58.4 |
HIP 59230 |
17.66 |
| 2026-07-30 12:00 |
12:08:02.25 |
-03:49:13.4 |
HIP 59230 |
13.81 |
| 2026-07-31 00:00 |
12:08:15.29 |
-03:51:28.8 |
HIP 59230 |
10.03 |
| 2026-07-31 12:00 |
12:08:28.40 |
-03:53:44.5 |
HIP 59230 |
6.43 |
| 2026-08-01 00:00 |
12:08:41.57 |
-03:56:00.5 |
HIP 59230 |
3.71 |
| 2026-08-01 12:00 |
12:08:54.82 |
-03:58:16.9 |
HIP 59230 |
4.25 |
| 2026-08-02 00:00 |
12:09:08.13 |
-04:00:33.6 |
HIP 59230 |
7.40 |
| 2026-08-02 12:00 |
12:09:21.51 |
-04:02:50.6 |
HIP 59230 |
11.14 |
| 2026-08-03 00:00 |
12:09:34.95 |
-04:05:08.0 |
HIP 59230 |
15.06 |
| 2026-08-03 12:00 |
12:09:48.46 |
-04:07:25.6 |
HIP 59230 |
19.05 |
| 2026-08-04 00:00 |
12:10:02.03 |
-04:09:43.6 |
HIP 59230 |
23.08 |
| 2026-08-04 12:00 |
12:10:15.67 |
-04:12:01.9 |
HIP 59230 |
27.15 |
| 2026-08-05 00:00 |
12:10:29.38 |
-04:14:20.5 |
HIP 59506 |
27.91 |
| 2026-08-05 12:00 |
12:10:43.14 |
-04:16:39.5 |
HIP 59506 |
23.90 |
| 2026-08-06 00:00 |
12:10:56.97 |
-04:18:58.7 |
HIP 59506 |
19.93 |
| 2026-08-06 12:00 |
12:11:10.86 |
-04:21:18.3 |
HIP 59506 |
16.05 |
| 2026-08-07 00:00 |
12:11:24.81 |
-04:23:38.1 |
HIP 59506 |
12.33 |
| 2026-08-07 12:00 |
12:11:38.82 |
-04:25:58.3 |
HIP 59506 |
9.02 |
| 2026-08-08 00:00 |
12:11:52.89 |
-04:28:18.8 |
HIP 59506 |
6.78 |
| 2026-08-08 12:00 |
12:12:07.02 |
-04:30:39.5 |
HIP 59506 |
6.79 |
| 2026-08-09 00:00 |
12:12:21.21 |
-04:33:00.6 |
HIP 59506 |
9.06 |
| 2026-08-09 12:00 |
12:12:35.45 |
-04:35:21.9 |
HIP 59506 |
12.43 |
| 2026-08-10 00:00 |
12:12:49.76 |
-04:37:43.6 |
HIP 59506 |
16.24 |
| 2026-08-10 12:00 |
12:13:04.12 |
-04:40:05.5 |
HIP 59506 |
20.24 |
| 2026-08-11 00:00 |
12:13:18.54 |
-04:42:27.7 |
HIP 59506 |
24.36 |
| 2026-08-11 12:00 |
12:13:33.01 |
-04:44:50.2 |
HIP 59506 |
28.54 |
| 2026-08-12 00:00 |
12:13:47.54 |
-04:47:12.9 |
HIP 59506 |
32.77 |
| 2026-08-12 12:00 |
12:14:02.12 |
-04:49:36.0 |
HIP 59506 |
37.04 |
| 2026-08-13 00:00 |
12:14:16.75 |
-04:51:59.3 |
HIP 59842 |
38.78 |
| 2026-08-13 12:00 |
12:14:31.44 |
-04:54:22.9 |
HIP 59842 |
37.74 |
| 2026-08-14 00:00 |
12:14:46.17 |
-04:56:46.7 |
HIP 59842 |
37.19 |
| 2026-08-14 12:00 |
12:15:00.96 |
-04:59:10.8 |
HIP 59842 |
37.14 |
| 2026-08-15 00:00 |
12:15:15.80 |
-05:01:35.1 |
HIP 59842 |
37.61 |
| 2026-08-15 12:00 |
12:15:30.69 |
-05:03:59.7 |
HIP 59842 |
38.59 |
| 2026-08-16 00:00 |
12:15:45.63 |
-05:06:24.6 |
HIP 60006 |
39.70 |
| 2026-08-16 12:00 |
12:16:00.62 |
-05:08:49.7 |
HIP 60006 |
36.38 |
| 2026-08-17 00:00 |
12:16:15.65 |
-05:11:15.0 |
HIP 60006 |
33.31 |
| 2026-08-17 12:00 |
12:16:30.73 |
-05:13:40.6 |
HIP 60006 |
30.58 |
| 2026-08-18 00:00 |
12:16:45.85 |
-05:16:06.4 |
HIP 60006 |
28.28 |
| 2026-08-18 12:00 |
12:17:01.02 |
-05:18:32.4 |
HIP 60006 |
26.55 |
| 2026-08-19 00:00 |
12:17:16.24 |
-05:20:58.7 |
HIP 60006 |
25.49 |