| 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) |
| 2026-09-20 00:00 |
16:41:45.64 |
-02:07:55.9 |
HIP 81742 |
0.93 |
| 2026-09-20 12:00 |
16:41:46.70 |
-02:08:31.2 |
HIP 81742 |
0.34 |
| 2026-09-21 00:00 |
16:41:47.82 |
-02:09:06.4 |
HIP 81742 |
0.43 |
| 2026-09-21 12:00 |
16:41:48.98 |
-02:09:41.6 |
HIP 81742 |
1.05 |
| 2026-09-22 00:00 |
16:41:50.19 |
-02:10:16.8 |
HIP 81742 |
1.70 |
| 2026-09-22 12:00 |
16:41:51.46 |
-02:10:51.9 |
HIP 81742 |
2.36 |
| 2026-09-23 00:00 |
16:41:52.78 |
-02:11:27.1 |
HIP 81742 |
3.03 |
| 2026-09-23 12:00 |
16:41:54.15 |
-02:12:02.2 |
HIP 81742 |
3.71 |
| 2026-09-24 00:00 |
16:41:55.57 |
-02:12:37.2 |
HIP 81742 |
4.39 |
| 2026-09-24 12:00 |
16:41:57.04 |
-02:13:12.3 |
HIP 81742 |
5.07 |
| 2026-09-25 00:00 |
16:41:58.56 |
-02:13:47.3 |
HIP 81742 |
5.77 |
| 2026-09-25 12:00 |
16:42:00.13 |
-02:14:22.3 |
HIP 81742 |
6.46 |
| 2026-09-26 00:00 |
16:42:01.75 |
-02:14:57.2 |
HIP 81742 |
7.17 |
| 2026-09-26 12:00 |
16:42:03.42 |
-02:15:32.1 |
HIP 81742 |
7.88 |
| 2026-09-27 00:00 |
16:42:05.14 |
-02:16:07.0 |
HIP 81742 |
8.60 |
| 2026-09-27 12:00 |
16:42:06.90 |
-02:16:41.8 |
HIP 81742 |
9.32 |
| 2026-09-28 00:00 |
16:42:08.72 |
-02:17:16.6 |
HIP 81742 |
10.05 |
| 2026-09-28 12:00 |
16:42:10.59 |
-02:17:51.3 |
HIP 81742 |
10.79 |
| 2026-09-29 00:00 |
16:42:12.50 |
-02:18:26.0 |
HIP 81742 |
11.53 |
| 2026-09-29 12:00 |
16:42:14.46 |
-02:19:00.6 |
HIP 81742 |
12.28 |
| 2026-09-30 00:00 |
16:42:16.47 |
-02:19:35.2 |
HIP 81742 |
13.04 |
| 2026-09-30 12:00 |
16:42:18.53 |
-02:20:09.7 |
HIP 81809 |
13.79 |
| 2026-10-01 00:00 |
16:42:20.64 |
-02:20:44.2 |
HIP 81809 |
14.22 |
| 2026-10-01 12:00 |
16:42:22.79 |
-02:21:18.6 |
HIP 81809 |
14.67 |
| 2026-10-02 00:00 |
16:42:24.99 |
-02:21:52.9 |
HIP 81809 |
15.14 |
| 2026-10-02 12:00 |
16:42:27.24 |
-02:22:27.2 |
HIP 81809 |
15.64 |
| 2026-10-03 00:00 |
16:42:29.54 |
-02:23:01.4 |
HIP 81809 |
16.16 |
| 2026-10-03 12:00 |
16:42:31.88 |
-02:23:35.5 |
HIP 81809 |
16.70 |
| 2026-10-04 00:00 |
16:42:34.27 |
-02:24:09.6 |
HIP 81809 |
17.26 |
| 2026-10-04 12:00 |
16:42:36.70 |
-02:24:43.5 |
HIP 81809 |
17.84 |
| 2026-10-05 00:00 |
16:42:39.18 |
-02:25:17.5 |
HIP 81809 |
18.44 |
| 2026-10-05 12:00 |
16:42:41.71 |
-02:25:51.3 |
HIP 81809 |
19.06 |
| 2026-10-06 00:00 |
16:42:44.28 |
-02:26:25.0 |
HIP 81809 |
19.70 |
| 2026-10-06 12:00 |
16:42:46.89 |
-02:26:58.7 |
HIP 81809 |
20.35 |
| 2026-10-07 00:00 |
16:42:49.56 |
-02:27:32.3 |
HIP 81920 |
19.69 |
| 2026-10-07 12:00 |
16:42:52.26 |
-02:28:05.8 |
HIP 81920 |
18.82 |
| 2026-10-08 00:00 |
16:42:55.01 |
-02:28:39.2 |
HIP 81920 |
17.94 |
| 2026-10-08 12:00 |
16:42:57.81 |
-02:29:12.5 |
HIP 81920 |
17.06 |
| 2026-10-09 00:00 |
16:43:00.65 |
-02:29:45.7 |
HIP 81920 |
16.17 |
| 2026-10-09 12:00 |
16:43:03.53 |
-02:30:18.8 |
HIP 81920 |
15.27 |
| 2026-10-10 00:00 |
16:43:06.45 |
-02:30:51.8 |
HIP 81920 |
14.36 |
| 2026-10-10 12:00 |
16:43:09.42 |
-02:31:24.7 |
HIP 81920 |
13.45 |
| 2026-10-11 00:00 |
16:43:12.43 |
-02:31:57.5 |
HIP 81920 |
12.53 |