| Parameter |
Value |
| Designation |
C/2022 R2 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2022-10-25T05:16:07.564800Z |
| Orbit solution date (soln_date, UTC) |
2025-01-14T17:42:12Z |
| Obs used |
295 |
| NEO |
- |
| M1 |
16.600 |
| K1 |
16.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2022-09-14T14:22:04.569600Z |
| Discovery magnitude (MPC) |
17.63 o |
| Discovery observatory (MPC) |
T08 · ATLAS-MLO, Mauna Loa |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2022-09-29.0000000 |
| e |
0.99850301 |
| q (au) |
0.632587 |
| a (au) |
422.571115 |
| i (deg) |
52.894812 |
| Ω (om, deg) |
60.403612 |
| ω (w, deg) |
78.376566 |
| M (ma, deg) |
359.997025 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.906 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.906 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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 |
| 2022-09-06 |
2022-09-18 |
-9.2857 |
+0.236 |
| 2022-09-18 |
2022-10-04 |
+15.1692 |
+0.457 |
| 2022-10-04 |
2022-10-22 |
-10.7635 |
-2.029 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
19:33:00.08 |
-60:59:32.6 |
HIP 96040 |
9.53 |
| 2026-03-26 12:00 |
19:33:07.02 |
-61:01:02.4 |
HIP 96040 |
10.45 |
| 2026-03-27 00:00 |
19:33:13.81 |
-61:02:32.5 |
HIP 96040 |
11.54 |
| 2026-03-27 12:00 |
19:33:20.46 |
-61:04:03.0 |
HIP 96040 |
12.76 |
| 2026-03-28 00:00 |
19:33:26.95 |
-61:05:34.0 |
HIP 96040 |
14.06 |
| 2026-03-28 12:00 |
19:33:33.29 |
-61:07:05.2 |
HIP 96040 |
15.42 |
| 2026-03-29 00:00 |
19:33:39.48 |
-61:08:36.9 |
HIP 96040 |
16.84 |
| 2026-03-29 12:00 |
19:33:45.51 |
-61:10:08.9 |
HIP 96040 |
18.29 |
| 2026-03-30 00:00 |
19:33:51.39 |
-61:11:41.3 |
HIP 96040 |
19.76 |
| 2026-03-30 12:00 |
19:33:57.12 |
-61:13:14.0 |
HIP 96040 |
21.26 |
| 2026-03-31 00:00 |
19:34:02.69 |
-61:14:47.1 |
HIP 96040 |
22.78 |
| 2026-03-31 12:00 |
19:34:08.11 |
-61:16:20.5 |
HIP 96040 |
24.30 |
| 2026-04-01 00:00 |
19:34:13.37 |
-61:17:54.3 |
HIP 96381 |
22.82 |
| 2026-04-01 12:00 |
19:34:18.47 |
-61:19:28.4 |
HIP 96381 |
21.15 |
| 2026-04-02 00:00 |
19:34:23.42 |
-61:21:02.8 |
HIP 96381 |
19.49 |
| 2026-04-02 12:00 |
19:34:28.20 |
-61:22:37.6 |
HIP 96381 |
17.84 |
| 2026-04-03 00:00 |
19:34:32.83 |
-61:24:12.7 |
HIP 96381 |
16.20 |
| 2026-04-03 12:00 |
19:34:37.30 |
-61:25:48.1 |
HIP 96381 |
14.58 |
| 2026-04-04 00:00 |
19:34:41.61 |
-61:27:23.8 |
HIP 96381 |
12.98 |
| 2026-04-04 12:00 |
19:34:45.76 |
-61:28:59.9 |
HIP 96381 |
11.40 |
| 2026-04-05 00:00 |
19:34:49.75 |
-61:30:36.2 |
HIP 96381 |
9.88 |
| 2026-04-05 12:00 |
19:34:53.57 |
-61:32:12.8 |
HIP 96381 |
8.42 |
| 2026-04-06 00:00 |
19:34:57.23 |
-61:33:49.8 |
HIP 96381 |
7.07 |
| 2026-04-06 12:00 |
19:35:00.73 |
-61:35:27.0 |
HIP 96381 |
5.91 |
| 2026-04-07 00:00 |
19:35:04.06 |
-61:37:04.5 |
HIP 96381 |
5.06 |
| 2026-04-07 12:00 |
19:35:07.23 |
-61:38:42.3 |
HIP 96381 |
4.70 |
| 2026-04-08 00:00 |
19:35:10.23 |
-61:40:20.3 |
HIP 96381 |
4.93 |
| 2026-04-08 12:00 |
19:35:13.06 |
-61:41:58.6 |
HIP 96381 |
5.69 |
| 2026-04-09 00:00 |
19:35:15.73 |
-61:43:37.2 |
HIP 96381 |
6.80 |
| 2026-04-09 12:00 |
19:35:18.23 |
-61:45:16.0 |
HIP 96381 |
8.12 |
| 2026-04-10 00:00 |
19:35:20.56 |
-61:46:55.0 |
HIP 96381 |
9.56 |
| 2026-04-10 12:00 |
19:35:22.72 |
-61:48:34.3 |
HIP 96381 |
11.07 |
| 2026-04-11 00:00 |
19:35:24.71 |
-61:50:13.9 |
HIP 96381 |
12.64 |
| 2026-04-11 12:00 |
19:35:26.53 |
-61:51:53.6 |
HIP 96381 |
14.23 |
| 2026-04-12 00:00 |
19:35:28.18 |
-61:53:33.6 |
HIP 96381 |
15.85 |
| 2026-04-12 12:00 |
19:35:29.66 |
-61:55:13.8 |
HIP 96381 |
17.49 |
| 2026-04-13 00:00 |
19:35:30.96 |
-61:56:54.2 |
HIP 96381 |
19.14 |
| 2026-04-13 12:00 |
19:35:32.09 |
-61:58:34.9 |
HIP 96381 |
20.80 |
| 2026-04-14 00:00 |
19:35:33.05 |
-62:00:15.7 |
HIP 96381 |
22.46 |
| 2026-04-14 12:00 |
19:35:33.83 |
-62:01:56.7 |
HIP 96272 |
22.17 |
| 2026-04-15 00:00 |
19:35:34.44 |
-62:03:37.8 |
HIP 96272 |
20.61 |
| 2026-04-15 12:00 |
19:35:34.87 |
-62:05:19.2 |
HIP 96272 |
19.05 |
| 2026-04-16 00:00 |
19:35:35.12 |
-62:07:00.7 |
HIP 96272 |
17.51 |