| 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) |
| 2026-07-29 00:00 |
18:44:32.04 |
-65:26:06.7 |
HIP 92148 |
18.38 |
| 2026-07-29 12:00 |
18:44:13.54 |
-65:25:36.3 |
HIP 92148 |
19.68 |
| 2026-07-30 00:00 |
18:43:55.15 |
-65:25:05.0 |
HIP 92148 |
21.06 |
| 2026-07-30 12:00 |
18:43:36.88 |
-65:24:32.8 |
HIP 92148 |
22.52 |
| 2026-07-31 00:00 |
18:43:18.73 |
-65:23:59.8 |
HIP 92148 |
24.04 |
| 2026-07-31 12:00 |
18:43:00.70 |
-65:23:25.9 |
HIP 92148 |
25.61 |
| 2026-08-01 00:00 |
18:42:42.79 |
-65:22:51.2 |
HIP 92148 |
27.21 |
| 2026-08-01 12:00 |
18:42:25.00 |
-65:22:15.7 |
HIP 92148 |
28.84 |
| 2026-08-02 00:00 |
18:42:07.34 |
-65:21:39.3 |
HIP 92148 |
30.50 |
| 2026-08-02 12:00 |
18:41:49.81 |
-65:21:02.1 |
HIP 92148 |
32.17 |
| 2026-08-03 00:00 |
18:41:32.40 |
-65:20:24.1 |
HIP 91456 |
32.24 |
| 2026-08-03 12:00 |
18:41:15.13 |
-65:19:45.3 |
HIP 91456 |
30.86 |
| 2026-08-04 00:00 |
18:40:57.98 |
-65:19:05.7 |
HIP 91456 |
29.53 |
| 2026-08-04 12:00 |
18:40:40.97 |
-65:18:25.3 |
HIP 91456 |
28.26 |
| 2026-08-05 00:00 |
18:40:24.10 |
-65:17:44.1 |
HIP 91456 |
27.06 |
| 2026-08-05 12:00 |
18:40:07.36 |
-65:17:02.2 |
HIP 91456 |
25.93 |
| 2026-08-06 00:00 |
18:39:50.76 |
-65:16:19.4 |
HIP 91456 |
24.89 |
| 2026-08-06 12:00 |
18:39:34.30 |
-65:15:35.9 |
HIP 91456 |
23.94 |
| 2026-08-07 00:00 |
18:39:17.98 |
-65:14:51.7 |
HIP 91456 |
23.09 |
| 2026-08-07 12:00 |
18:39:01.81 |
-65:14:06.7 |
HIP 91456 |
22.35 |
| 2026-08-08 00:00 |
18:38:45.78 |
-65:13:20.9 |
HIP 91456 |
21.73 |
| 2026-08-08 12:00 |
18:38:29.89 |
-65:12:34.4 |
HIP 91456 |
21.24 |
| 2026-08-09 00:00 |
18:38:14.15 |
-65:11:47.2 |
HIP 91456 |
20.89 |
| 2026-08-09 12:00 |
18:37:58.56 |
-65:10:59.2 |
HIP 91456 |
20.68 |
| 2026-08-10 00:00 |
18:37:43.12 |
-65:10:10.6 |
HIP 91456 |
20.62 |
| 2026-08-10 12:00 |
18:37:27.84 |
-65:09:21.2 |
HIP 91456 |
20.69 |
| 2026-08-11 00:00 |
18:37:12.70 |
-65:08:31.1 |
HIP 91278 |
20.19 |
| 2026-08-11 12:00 |
18:36:57.72 |
-65:07:40.4 |
HIP 91278 |
19.38 |
| 2026-08-12 00:00 |
18:36:42.90 |
-65:06:49.0 |
HIP 91278 |
18.69 |
| 2026-08-12 12:00 |
18:36:28.23 |
-65:05:56.9 |
HIP 91278 |
18.13 |
| 2026-08-13 00:00 |
18:36:13.72 |
-65:05:04.1 |
HIP 91278 |
17.72 |
| 2026-08-13 12:00 |
18:35:59.37 |
-65:04:10.6 |
HIP 91278 |
17.47 |
| 2026-08-14 00:00 |
18:35:45.19 |
-65:03:16.6 |
HIP 91278 |
17.37 |
| 2026-08-14 12:00 |
18:35:31.16 |
-65:02:21.9 |
HIP 91278 |
17.44 |
| 2026-08-15 00:00 |
18:35:17.30 |
-65:01:26.5 |
HIP 91278 |
17.65 |
| 2026-08-15 12:00 |
18:35:03.60 |
-65:00:30.5 |
HIP 91278 |
18.02 |
| 2026-08-16 00:00 |
18:34:50.06 |
-64:59:34.0 |
HIP 91278 |
18.52 |
| 2026-08-16 12:00 |
18:34:36.69 |
-64:58:36.8 |
HIP 91278 |
19.14 |
| 2026-08-17 00:00 |
18:34:23.49 |
-64:57:39.0 |
HIP 91278 |
19.87 |
| 2026-08-17 12:00 |
18:34:10.46 |
-64:56:40.7 |
HIP 90927 |
20.69 |
| 2026-08-18 00:00 |
18:33:57.59 |
-64:55:41.7 |
HIP 90927 |
21.12 |
| 2026-08-18 12:00 |
18:33:44.89 |
-64:54:42.2 |
HIP 90927 |
21.69 |
| 2026-08-19 00:00 |
18:33:32.37 |
-64:53:42.2 |
HIP 90927 |
22.38 |