| Parameter |
Value |
| Designation |
C/2018 V2 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-11-26T23:28:47.184960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:46Z |
| Obs used |
173 |
| NEO |
- |
| M1 |
13.600 |
| K1 |
12.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2018-11-02T12:38:26.880000Z |
| Discovery magnitude (MPC) |
19.10 o |
| Discovery observatory (MPC) |
T08 · ATLAS-MLO, Mauna Loa |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-03-18.0000000 |
| e |
0.90288516 |
| q (au) |
2.474837 |
| a (au) |
25.483616 |
| i (deg) |
159.109919 |
| Ω (om, deg) |
356.790851 |
| ω (w, deg) |
318.662491 |
| M (ma, deg) |
0.850590 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.246 + 5.480\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.246 |
| n |
5.480 |
| gf |
1.000 |
| gb |
-0.951 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
16:45:08.48 |
-01:13:02.3 |
HIP 82070 |
10.55 |
| 2026-07-29 12:00 |
16:45:03.67 |
-01:13:24.7 |
HIP 82070 |
11.63 |
| 2026-07-30 00:00 |
16:44:58.92 |
-01:13:47.4 |
HIP 82070 |
12.73 |
| 2026-07-30 12:00 |
16:44:54.21 |
-01:14:10.3 |
HIP 82070 |
13.84 |
| 2026-07-31 00:00 |
16:44:49.56 |
-01:14:33.4 |
HIP 82070 |
14.96 |
| 2026-07-31 12:00 |
16:44:44.95 |
-01:14:56.7 |
HIP 82070 |
16.08 |
| 2026-08-01 00:00 |
16:44:40.40 |
-01:15:20.3 |
HIP 82070 |
17.20 |
| 2026-08-01 12:00 |
16:44:35.90 |
-01:15:44.2 |
HIP 82070 |
18.32 |
| 2026-08-02 00:00 |
16:44:31.45 |
-01:16:08.2 |
HIP 82070 |
19.43 |
| 2026-08-02 12:00 |
16:44:27.05 |
-01:16:32.5 |
HIP 82070 |
20.54 |
| 2026-08-03 00:00 |
16:44:22.71 |
-01:16:57.0 |
HIP 82070 |
21.64 |
| 2026-08-03 12:00 |
16:44:18.42 |
-01:17:21.8 |
HIP 82070 |
22.73 |
| 2026-08-04 00:00 |
16:44:14.18 |
-01:17:46.8 |
HIP 82070 |
23.82 |
| 2026-08-04 12:00 |
16:44:09.99 |
-01:18:12.0 |
HIP 82070 |
24.90 |
| 2026-08-05 00:00 |
16:44:05.86 |
-01:18:37.4 |
HIP 82070 |
25.97 |
| 2026-08-05 12:00 |
16:44:01.78 |
-01:19:03.0 |
HIP 82070 |
27.03 |
| 2026-08-06 00:00 |
16:43:57.76 |
-01:19:28.9 |
HIP 82040 |
27.86 |
| 2026-08-06 12:00 |
16:43:53.79 |
-01:19:54.9 |
HIP 82040 |
28.47 |
| 2026-08-07 00:00 |
16:43:49.87 |
-01:20:21.2 |
HIP 82040 |
29.09 |
| 2026-08-07 12:00 |
16:43:46.00 |
-01:20:47.7 |
HIP 82040 |
29.73 |
| 2026-08-08 00:00 |
16:43:42.20 |
-01:21:14.4 |
HIP 82040 |
30.37 |
| 2026-08-08 12:00 |
16:43:38.44 |
-01:21:41.3 |
HIP 82040 |
31.03 |
| 2026-08-09 00:00 |
16:43:34.74 |
-01:22:08.4 |
HIP 81802 |
30.45 |
| 2026-08-09 12:00 |
16:43:31.10 |
-01:22:35.8 |
HIP 81802 |
29.58 |
| 2026-08-10 00:00 |
16:43:27.51 |
-01:23:03.3 |
HIP 81802 |
28.72 |
| 2026-08-10 12:00 |
16:43:23.97 |
-01:23:31.0 |
HIP 81802 |
27.88 |
| 2026-08-11 00:00 |
16:43:20.50 |
-01:23:58.9 |
HIP 81802 |
27.05 |
| 2026-08-11 12:00 |
16:43:17.07 |
-01:24:27.0 |
HIP 81802 |
26.24 |
| 2026-08-12 00:00 |
16:43:13.71 |
-01:24:55.3 |
HIP 81802 |
25.43 |
| 2026-08-12 12:00 |
16:43:10.39 |
-01:25:23.7 |
HIP 81802 |
24.65 |
| 2026-08-13 00:00 |
16:43:07.14 |
-01:25:52.4 |
HIP 81802 |
23.88 |
| 2026-08-13 12:00 |
16:43:03.94 |
-01:26:21.2 |
HIP 81802 |
23.12 |
| 2026-08-14 00:00 |
16:43:00.80 |
-01:26:50.3 |
HIP 81802 |
22.38 |
| 2026-08-14 12:00 |
16:42:57.71 |
-01:27:19.5 |
HIP 81802 |
21.66 |
| 2026-08-15 00:00 |
16:42:54.69 |
-01:27:48.8 |
HIP 81802 |
20.95 |
| 2026-08-15 12:00 |
16:42:51.71 |
-01:28:18.4 |
HIP 81802 |
20.26 |
| 2026-08-16 00:00 |
16:42:48.80 |
-01:28:48.1 |
HIP 81802 |
19.58 |
| 2026-08-16 12:00 |
16:42:45.94 |
-01:29:18.0 |
HIP 81802 |
18.93 |
| 2026-08-17 00:00 |
16:42:43.14 |
-01:29:48.0 |
HIP 81802 |
18.29 |
| 2026-08-17 12:00 |
16:42:40.39 |
-01:30:18.2 |
HIP 81802 |
17.67 |
| 2026-08-18 00:00 |
16:42:37.71 |
-01:30:48.5 |
HIP 81802 |
17.07 |
| 2026-08-18 12:00 |
16:42:35.08 |
-01:31:19.1 |
HIP 81802 |
16.49 |
| 2026-08-19 00:00 |
16:42:32.50 |
-01:31:49.7 |
HIP 81802 |
15.93 |