| 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 |
-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 |
| 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) |
| 2026-09-20 00:00 |
18:26:19.84 |
-63:36:39.5 |
HIP 90155 |
21.24 |
| 2026-09-20 12:00 |
18:26:18.89 |
-63:35:20.8 |
HIP 90501 |
20.25 |
| 2026-09-21 00:00 |
18:26:18.11 |
-63:34:02.1 |
HIP 90501 |
19.25 |
| 2026-09-21 12:00 |
18:26:17.50 |
-63:32:43.3 |
HIP 90501 |
18.28 |
| 2026-09-22 00:00 |
18:26:17.06 |
-63:31:24.5 |
HIP 90501 |
17.33 |
| 2026-09-22 12:00 |
18:26:16.79 |
-63:30:05.7 |
HIP 90501 |
16.43 |
| 2026-09-23 00:00 |
18:26:16.69 |
-63:28:46.8 |
HIP 90501 |
15.56 |
| 2026-09-23 12:00 |
18:26:16.76 |
-63:27:28.0 |
HIP 90501 |
14.75 |
| 2026-09-24 00:00 |
18:26:17.00 |
-63:26:09.2 |
HIP 90501 |
14.00 |
| 2026-09-24 12:00 |
18:26:17.41 |
-63:24:50.3 |
HIP 90501 |
13.32 |
| 2026-09-25 00:00 |
18:26:17.98 |
-63:23:31.5 |
HIP 90501 |
12.72 |
| 2026-09-25 12:00 |
18:26:18.73 |
-63:22:12.8 |
HIP 90501 |
12.21 |
| 2026-09-26 00:00 |
18:26:19.63 |
-63:20:54.0 |
HIP 90501 |
11.82 |
| 2026-09-26 12:00 |
18:26:20.71 |
-63:19:35.3 |
HIP 90501 |
11.54 |
| 2026-09-27 00:00 |
18:26:21.94 |
-63:18:16.6 |
HIP 90501 |
11.39 |
| 2026-09-27 12:00 |
18:26:23.35 |
-63:16:57.9 |
HIP 90501 |
11.37 |
| 2026-09-28 00:00 |
18:26:24.91 |
-63:15:39.3 |
HIP 90501 |
11.48 |
| 2026-09-28 12:00 |
18:26:26.64 |
-63:14:20.8 |
HIP 90501 |
11.73 |
| 2026-09-29 00:00 |
18:26:28.53 |
-63:13:02.3 |
HIP 90501 |
12.10 |
| 2026-09-29 12:00 |
18:26:30.59 |
-63:11:43.9 |
HIP 90304 |
12.40 |
| 2026-09-30 00:00 |
18:26:32.80 |
-63:10:25.5 |
HIP 90304 |
11.47 |
| 2026-09-30 12:00 |
18:26:35.18 |
-63:09:07.3 |
HIP 90304 |
10.64 |
| 2026-10-01 00:00 |
18:26:37.71 |
-63:07:49.1 |
HIP 90304 |
9.94 |
| 2026-10-01 12:00 |
18:26:40.40 |
-63:06:30.9 |
HIP 90304 |
9.39 |
| 2026-10-02 00:00 |
18:26:43.26 |
-63:05:12.9 |
HIP 90304 |
9.02 |
| 2026-10-02 12:00 |
18:26:46.27 |
-63:03:55.0 |
HIP 90304 |
8.86 |
| 2026-10-03 00:00 |
18:26:49.44 |
-63:02:37.2 |
HIP 90304 |
8.92 |
| 2026-10-03 12:00 |
18:26:52.76 |
-63:01:19.4 |
HIP 90304 |
9.20 |
| 2026-10-04 00:00 |
18:26:56.24 |
-63:00:01.8 |
HIP 90304 |
9.68 |
| 2026-10-04 12:00 |
18:26:59.88 |
-62:58:44.3 |
HIP 90304 |
10.33 |
| 2026-10-05 00:00 |
18:27:03.67 |
-62:57:27.0 |
HIP 90304 |
11.13 |
| 2026-10-05 12:00 |
18:27:07.62 |
-62:56:09.7 |
HIP 90304 |
12.04 |
| 2026-10-06 00:00 |
18:27:11.72 |
-62:54:52.6 |
HIP 90304 |
13.05 |
| 2026-10-06 12:00 |
18:27:15.97 |
-62:53:35.6 |
HIP 90304 |
14.13 |
| 2026-10-07 00:00 |
18:27:20.38 |
-62:52:18.8 |
HIP 90304 |
15.27 |
| 2026-10-07 12:00 |
18:27:24.94 |
-62:51:02.1 |
HIP 90304 |
16.46 |
| 2026-10-08 00:00 |
18:27:29.65 |
-62:49:45.6 |
HIP 90304 |
17.69 |
| 2026-10-08 12:00 |
18:27:34.51 |
-62:48:29.2 |
HIP 90304 |
18.95 |
| 2026-10-09 00:00 |
18:27:39.52 |
-62:47:13.0 |
HIP 90304 |
20.24 |
| 2026-10-09 12:00 |
18:27:44.68 |
-62:45:56.9 |
HIP 90304 |
21.56 |
| 2026-10-10 00:00 |
18:27:49.98 |
-62:44:41.0 |
HIP 90304 |
22.89 |
| 2026-10-10 12:00 |
18:27:55.44 |
-62:43:25.3 |
HIP 90278 |
22.91 |
| 2026-10-11 00:00 |
18:28:01.04 |
-62:42:09.8 |
HIP 90278 |
22.75 |