| 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) |
| 2026-07-29 00:00 |
17:26:26.35 |
+07:46:54.2 |
HIP 85346 |
9.66 |
| 2026-07-29 12:00 |
17:26:22.47 |
+07:46:24.3 |
HIP 85346 |
9.17 |
| 2026-07-30 00:00 |
17:26:18.65 |
+07:45:54.0 |
HIP 85346 |
8.78 |
| 2026-07-30 12:00 |
17:26:14.87 |
+07:45:23.4 |
HIP 85346 |
8.50 |
| 2026-07-31 00:00 |
17:26:11.15 |
+07:44:52.4 |
HIP 85346 |
8.33 |
| 2026-07-31 12:00 |
17:26:07.48 |
+07:44:21.0 |
HIP 85346 |
8.29 |
| 2026-08-01 00:00 |
17:26:03.87 |
+07:43:49.2 |
HIP 85346 |
8.36 |
| 2026-08-01 12:00 |
17:26:00.30 |
+07:43:17.0 |
HIP 85346 |
8.55 |
| 2026-08-02 00:00 |
17:25:56.79 |
+07:42:44.5 |
HIP 85346 |
8.84 |
| 2026-08-02 12:00 |
17:25:53.34 |
+07:42:11.7 |
HIP 85333 |
9.06 |
| 2026-08-03 00:00 |
17:25:49.93 |
+07:41:38.5 |
HIP 85333 |
9.31 |
| 2026-08-03 12:00 |
17:25:46.59 |
+07:41:04.9 |
HIP 85333 |
9.65 |
| 2026-08-04 00:00 |
17:25:43.29 |
+07:40:31.0 |
HIP 85333 |
10.06 |
| 2026-08-04 12:00 |
17:25:40.05 |
+07:39:56.7 |
HIP 85287 |
9.86 |
| 2026-08-05 00:00 |
17:25:36.87 |
+07:39:22.1 |
HIP 85287 |
9.30 |
| 2026-08-05 12:00 |
17:25:33.74 |
+07:38:47.2 |
HIP 85287 |
8.81 |
| 2026-08-06 00:00 |
17:25:30.67 |
+07:38:11.9 |
HIP 85287 |
8.39 |
| 2026-08-06 12:00 |
17:25:27.66 |
+07:37:36.3 |
HIP 85287 |
8.06 |
| 2026-08-07 00:00 |
17:25:24.70 |
+07:37:00.3 |
HIP 85287 |
7.82 |
| 2026-08-07 12:00 |
17:25:21.80 |
+07:36:24.1 |
HIP 85287 |
7.67 |
| 2026-08-08 00:00 |
17:25:18.96 |
+07:35:47.5 |
HIP 85287 |
7.63 |
| 2026-08-08 12:00 |
17:25:16.17 |
+07:35:10.6 |
HIP 85287 |
7.69 |
| 2026-08-09 00:00 |
17:25:13.44 |
+07:34:33.4 |
HIP 85287 |
7.84 |
| 2026-08-09 12:00 |
17:25:10.77 |
+07:33:55.8 |
HIP 85287 |
8.07 |
| 2026-08-10 00:00 |
17:25:08.16 |
+07:33:18.0 |
HIP 85287 |
8.39 |
| 2026-08-10 12:00 |
17:25:05.61 |
+07:32:39.9 |
HIP 85287 |
8.77 |
| 2026-08-11 00:00 |
17:25:03.11 |
+07:32:01.4 |
HIP 85287 |
9.20 |
| 2026-08-11 12:00 |
17:25:00.68 |
+07:31:22.7 |
HIP 85287 |
9.69 |
| 2026-08-12 00:00 |
17:24:58.31 |
+07:30:43.7 |
HIP 85287 |
10.21 |
| 2026-08-12 12:00 |
17:24:55.99 |
+07:30:04.4 |
HIP 85287 |
10.76 |
| 2026-08-13 00:00 |
17:24:53.74 |
+07:29:24.9 |
HIP 85287 |
11.34 |
| 2026-08-13 12:00 |
17:24:51.54 |
+07:28:45.0 |
HIP 85287 |
11.94 |
| 2026-08-14 00:00 |
17:24:49.41 |
+07:28:04.9 |
HIP 85287 |
12.56 |
| 2026-08-14 12:00 |
17:24:47.34 |
+07:27:24.5 |
HIP 85287 |
13.18 |
| 2026-08-15 00:00 |
17:24:45.33 |
+07:26:43.9 |
HIP 85287 |
13.82 |
| 2026-08-15 12:00 |
17:24:43.38 |
+07:26:03.0 |
HIP 85287 |
14.47 |
| 2026-08-16 00:00 |
17:24:41.49 |
+07:25:21.9 |
HIP 85287 |
15.12 |
| 2026-08-16 12:00 |
17:24:39.67 |
+07:24:40.5 |
HIP 85287 |
15.77 |
| 2026-08-17 00:00 |
17:24:37.90 |
+07:23:58.9 |
HIP 85287 |
16.43 |
| 2026-08-17 12:00 |
17:24:36.20 |
+07:23:17.0 |
HIP 85287 |
17.09 |
| 2026-08-18 00:00 |
17:24:34.56 |
+07:22:34.9 |
HIP 85287 |
17.74 |
| 2026-08-18 12:00 |
17:24:32.99 |
+07:21:52.6 |
HIP 85287 |
18.40 |
| 2026-08-19 00:00 |
17:24:31.47 |
+07:21:10.0 |
HIP 85287 |
19.06 |