| 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) |
| 2026-09-25 00:00 |
17:25:36.27 |
+06:23:16.2 |
HIP 85251 |
5.90 |
| 2026-09-25 12:00 |
17:25:39.51 |
+06:22:28.8 |
HIP 85251 |
6.97 |
| 2026-09-26 00:00 |
17:25:42.81 |
+06:21:41.5 |
HIP 85251 |
8.07 |
| 2026-09-26 12:00 |
17:25:46.17 |
+06:20:54.4 |
HIP 85251 |
9.20 |
| 2026-09-27 00:00 |
17:25:49.59 |
+06:20:07.3 |
HIP 85251 |
10.33 |
| 2026-09-27 12:00 |
17:25:53.07 |
+06:19:20.3 |
HIP 85251 |
11.49 |
| 2026-09-28 00:00 |
17:25:56.61 |
+06:18:33.4 |
HIP 85251 |
12.65 |
| 2026-09-28 12:00 |
17:26:00.21 |
+06:17:46.7 |
HIP 85251 |
13.83 |
| 2026-09-29 00:00 |
17:26:03.86 |
+06:17:00.0 |
HIP 85251 |
15.02 |
| 2026-09-29 12:00 |
17:26:07.58 |
+06:16:13.5 |
HIP 85251 |
16.23 |
| 2026-09-30 00:00 |
17:26:11.35 |
+06:15:27.1 |
HIP 85251 |
17.44 |
| 2026-09-30 12:00 |
17:26:15.18 |
+06:14:40.8 |
HIP 85251 |
18.66 |
| 2026-10-01 00:00 |
17:26:19.07 |
+06:13:54.6 |
HIP 85251 |
19.90 |
| 2026-10-01 12:00 |
17:26:23.01 |
+06:13:08.5 |
HIP 85251 |
21.14 |
| 2026-10-02 00:00 |
17:26:27.02 |
+06:12:22.6 |
HIP 85251 |
22.40 |
| 2026-10-02 12:00 |
17:26:31.08 |
+06:11:36.8 |
HIP 85428 |
23.41 |
| 2026-10-03 00:00 |
17:26:35.20 |
+06:10:51.2 |
HIP 85428 |
23.50 |
| 2026-10-03 12:00 |
17:26:39.38 |
+06:10:05.7 |
HIP 85428 |
23.65 |
| 2026-10-04 00:00 |
17:26:43.61 |
+06:09:20.3 |
HIP 85428 |
23.86 |
| 2026-10-04 12:00 |
17:26:47.90 |
+06:08:35.1 |
HIP 85428 |
24.14 |
| 2026-10-05 00:00 |
17:26:52.25 |
+06:07:50.1 |
HIP 85428 |
24.47 |
| 2026-10-05 12:00 |
17:26:56.65 |
+06:07:05.2 |
HIP 85428 |
24.86 |
| 2026-10-06 00:00 |
17:27:01.11 |
+06:06:20.4 |
HIP 85428 |
25.31 |
| 2026-10-06 12:00 |
17:27:05.63 |
+06:05:35.9 |
HIP 85428 |
25.82 |
| 2026-10-07 00:00 |
17:27:10.20 |
+06:04:51.5 |
HIP 85428 |
26.38 |
| 2026-10-07 12:00 |
17:27:14.82 |
+06:04:07.2 |
HIP 85428 |
26.99 |
| 2026-10-08 00:00 |
17:27:19.50 |
+06:03:23.2 |
HIP 85428 |
27.65 |
| 2026-10-08 12:00 |
17:27:24.24 |
+06:02:39.3 |
HIP 85564 |
26.92 |
| 2026-10-09 00:00 |
17:27:29.03 |
+06:01:55.6 |
HIP 85564 |
25.95 |
| 2026-10-09 12:00 |
17:27:33.88 |
+06:01:12.1 |
HIP 85564 |
25.00 |
| 2026-10-10 00:00 |
17:27:38.78 |
+06:00:28.8 |
HIP 85564 |
24.09 |
| 2026-10-10 12:00 |
17:27:43.73 |
+05:59:45.7 |
HIP 85564 |
23.21 |
| 2026-10-11 00:00 |
17:27:48.74 |
+05:59:02.7 |
HIP 85564 |
22.38 |
| 2026-10-11 12:00 |
17:27:53.80 |
+05:58:20.0 |
HIP 85564 |
21.60 |
| 2026-10-12 00:00 |
17:27:58.91 |
+05:57:37.5 |
HIP 85564 |
20.87 |
| 2026-10-12 12:00 |
17:28:04.08 |
+05:56:55.2 |
HIP 85564 |
20.22 |
| 2026-10-13 00:00 |
17:28:09.30 |
+05:56:13.1 |
HIP 85564 |
19.63 |
| 2026-10-13 12:00 |
17:28:14.57 |
+05:55:31.2 |
HIP 85564 |
19.13 |
| 2026-10-14 00:00 |
17:28:19.89 |
+05:54:49.5 |
HIP 85564 |
18.73 |
| 2026-10-14 12:00 |
17:28:25.26 |
+05:54:08.1 |
HIP 85564 |
18.42 |
| 2026-10-15 00:00 |
17:28:30.68 |
+05:53:26.9 |
HIP 85564 |
18.23 |
| 2026-10-15 12:00 |
17:28:36.16 |
+05:52:45.9 |
HIP 85564 |
18.15 |
| 2026-10-16 00:00 |
17:28:41.68 |
+05:52:05.1 |
HIP 85564 |
18.19 |