| Parameter |
Value |
| Designation |
C/2019 C1 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2020-05-05T17:23:03.788160Z |
| Orbit solution date (soln_date, UTC) |
2021-08-06T00:42:31Z |
| Obs used |
739 |
| NEO |
- |
| M1 |
6.500 |
| K1 |
9.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-02-05T11:02:21.926400Z |
| Discovery magnitude (MPC) |
17.75 o |
| Discovery observatory (MPC) |
T08 · ATLAS-MLO, Mauna Loa |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-04-24.0000000 |
| e |
0.99209888 |
| q (au) |
6.581320 |
| a (au) |
832.959952 |
| i (deg) |
36.016489 |
| Ω (om, deg) |
212.397225 |
| ω (w, deg) |
319.189707 |
| M (ma, deg) |
359.999519 |
Magnitude
Scatter + Global Linear
$$
M_a = (0.402 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
0.402 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.501 |
| 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) |
| 2026-05-12 00:00 |
17:41:17.77 |
+07:22:53.4 |
HIP 86440 |
26.28 |
| 2026-05-12 12:00 |
17:41:12.78 |
+07:23:42.4 |
HIP 86440 |
25.62 |
| 2026-05-13 00:00 |
17:41:07.74 |
+07:24:31.0 |
HIP 86440 |
25.01 |
| 2026-05-13 12:00 |
17:41:02.66 |
+07:25:19.2 |
HIP 86440 |
24.47 |
| 2026-05-14 00:00 |
17:40:57.55 |
+07:26:06.9 |
HIP 86440 |
23.99 |
| 2026-05-14 12:00 |
17:40:52.39 |
+07:26:54.2 |
HIP 86440 |
23.59 |
| 2026-05-15 00:00 |
17:40:47.19 |
+07:27:41.0 |
HIP 86440 |
23.26 |
| 2026-05-15 12:00 |
17:40:41.95 |
+07:28:27.4 |
HIP 86457 |
22.68 |
| 2026-05-16 00:00 |
17:40:36.67 |
+07:29:13.4 |
HIP 86457 |
21.38 |
| 2026-05-16 12:00 |
17:40:31.35 |
+07:29:58.9 |
HIP 86457 |
20.10 |
| 2026-05-17 00:00 |
17:40:26.00 |
+07:30:43.9 |
HIP 86457 |
18.87 |
| 2026-05-17 12:00 |
17:40:20.61 |
+07:31:28.5 |
HIP 86457 |
17.68 |
| 2026-05-18 00:00 |
17:40:15.18 |
+07:32:12.6 |
HIP 86457 |
16.56 |
| 2026-05-18 12:00 |
17:40:09.72 |
+07:32:56.3 |
HIP 86457 |
15.51 |
| 2026-05-19 00:00 |
17:40:04.22 |
+07:33:39.5 |
HIP 86457 |
14.56 |
| 2026-05-19 12:00 |
17:39:58.69 |
+07:34:22.2 |
HIP 86457 |
13.72 |
| 2026-05-20 00:00 |
17:39:53.12 |
+07:35:04.4 |
HIP 86457 |
13.01 |
| 2026-05-20 12:00 |
17:39:47.52 |
+07:35:46.2 |
HIP 86457 |
12.48 |
| 2026-05-21 00:00 |
17:39:41.89 |
+07:36:27.4 |
HIP 86457 |
12.12 |
| 2026-05-21 12:00 |
17:39:36.23 |
+07:37:08.2 |
HIP 86457 |
11.97 |
| 2026-05-22 00:00 |
17:39:30.54 |
+07:37:48.5 |
HIP 86457 |
12.04 |
| 2026-05-22 12:00 |
17:39:24.81 |
+07:38:28.4 |
HIP 86457 |
12.31 |
| 2026-05-23 00:00 |
17:39:19.06 |
+07:39:07.7 |
HIP 86457 |
12.79 |
| 2026-05-23 12:00 |
17:39:13.27 |
+07:39:46.5 |
HIP 86457 |
13.44 |
| 2026-05-24 00:00 |
17:39:07.46 |
+07:40:24.9 |
HIP 86457 |
14.24 |
| 2026-05-24 12:00 |
17:39:01.62 |
+07:41:02.7 |
HIP 86457 |
15.18 |
| 2026-05-25 00:00 |
17:38:55.76 |
+07:41:40.0 |
HIP 86457 |
16.23 |
| 2026-05-25 12:00 |
17:38:49.86 |
+07:42:16.9 |
HIP 86457 |
17.37 |
| 2026-05-26 00:00 |
17:38:43.95 |
+07:42:53.2 |
HIP 86457 |
18.58 |
| 2026-05-26 12:00 |
17:38:38.00 |
+07:43:29.0 |
HIP 86457 |
19.85 |
| 2026-05-27 00:00 |
17:38:32.03 |
+07:44:04.4 |
HIP 86457 |
21.17 |
| 2026-05-27 12:00 |
17:38:26.04 |
+07:44:39.2 |
HIP 86457 |
22.53 |
| 2026-05-28 00:00 |
17:38:20.02 |
+07:45:13.5 |
HIP 86457 |
23.93 |
| 2026-05-28 12:00 |
17:38:13.99 |
+07:45:47.3 |
HIP 86457 |
25.36 |
| 2026-05-29 00:00 |
17:38:07.93 |
+07:46:20.5 |
HIP 86457 |
26.81 |
| 2026-05-29 12:00 |
17:38:01.84 |
+07:46:53.3 |
HIP 86457 |
28.29 |
| 2026-05-30 00:00 |
17:37:55.74 |
+07:47:25.5 |
HIP 86457 |
29.78 |
| 2026-05-30 12:00 |
17:37:49.62 |
+07:47:57.3 |
HIP 86457 |
31.29 |
| 2026-05-31 00:00 |
17:37:43.47 |
+07:48:28.5 |
HIP 86174 |
31.06 |
| 2026-05-31 12:00 |
17:37:37.31 |
+07:48:59.1 |
HIP 86174 |
30.69 |
| 2026-06-01 00:00 |
17:37:31.13 |
+07:49:29.3 |
HIP 86174 |
30.39 |
| 2026-06-01 12:00 |
17:37:24.93 |
+07:49:58.9 |
HIP 86174 |
30.16 |
| 2026-06-02 00:00 |
17:37:18.72 |
+07:50:28.0 |
HIP 86174 |
30.01 |