| Parameter |
Value |
| Designation |
490P/ATLAS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2019-06-22T16:00:54.581760Z |
| Orbit solution date (soln_date, UTC) |
2024-12-03T17:12:47Z |
| Obs used |
368 |
| NEO |
Yes |
| M1 |
20.500 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-06-29T13:56:52.051200Z |
| Discovery magnitude (MPC) |
18.36 o |
| Discovery observatory (MPC) |
T08 · ATLAS-MLO, Mauna Loa |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-12-01.0000000 |
| e |
0.64849913 |
| q (au) |
1.063456 |
| a (au) |
3.025473 |
| i (deg) |
12.281885 |
| Ω (om, deg) |
307.601988 |
| ω (w, deg) |
332.525414 |
| M (ma, deg) |
30.215976 |
Magnitude
Scatter + Global Linear
$$
M_a = (19.669 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
19.669 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.735 |
| k |
0.975 |
| 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 |
06:46:52.08 |
+30:50:23.5 |
HIP 32583 |
18.55 |
| 2026-09-25 12:00 |
06:47:02.90 |
+30:50:42.2 |
HIP 32583 |
16.67 |
| 2026-09-26 00:00 |
06:47:13.52 |
+30:51:01.2 |
HIP 32583 |
14.94 |
| 2026-09-26 12:00 |
06:47:23.93 |
+30:51:20.6 |
HIP 32583 |
13.41 |
| 2026-09-27 00:00 |
06:47:34.14 |
+30:51:40.2 |
HIP 32583 |
12.11 |
| 2026-09-27 12:00 |
06:47:44.13 |
+30:52:00.2 |
HIP 32583 |
11.12 |
| 2026-09-28 00:00 |
06:47:53.92 |
+30:52:20.5 |
HIP 32583 |
10.48 |
| 2026-09-28 12:00 |
06:48:03.49 |
+30:52:41.1 |
HIP 32583 |
10.24 |
| 2026-09-29 00:00 |
06:48:12.86 |
+30:53:02.0 |
HIP 32583 |
10.40 |
| 2026-09-29 12:00 |
06:48:22.00 |
+30:53:23.3 |
HIP 32583 |
10.91 |
| 2026-09-30 00:00 |
06:48:30.94 |
+30:53:44.8 |
HIP 32583 |
11.71 |
| 2026-09-30 12:00 |
06:48:39.66 |
+30:54:06.7 |
HIP 32583 |
12.72 |
| 2026-10-01 00:00 |
06:48:48.16 |
+30:54:28.9 |
HIP 32583 |
13.88 |
| 2026-10-01 12:00 |
06:48:56.44 |
+30:54:51.5 |
HIP 32583 |
15.14 |
| 2026-10-02 00:00 |
06:49:04.50 |
+30:55:14.3 |
HIP 32583 |
16.45 |
| 2026-10-02 12:00 |
06:49:12.34 |
+30:55:37.5 |
HIP 32583 |
17.80 |
| 2026-10-03 00:00 |
06:49:19.95 |
+30:56:01.1 |
HIP 32583 |
19.16 |
| 2026-10-03 12:00 |
06:49:27.34 |
+30:56:24.9 |
HIP 32583 |
20.52 |
| 2026-10-04 00:00 |
06:49:34.51 |
+30:56:49.1 |
HIP 32583 |
21.87 |
| 2026-10-04 12:00 |
06:49:41.45 |
+30:57:13.6 |
HIP 32651 |
22.97 |
| 2026-10-05 00:00 |
06:49:48.16 |
+30:57:38.5 |
HIP 32651 |
23.50 |
| 2026-10-05 12:00 |
06:49:54.64 |
+30:58:03.7 |
HIP 32651 |
24.08 |
| 2026-10-06 00:00 |
06:50:00.89 |
+30:58:29.2 |
HIP 32651 |
24.68 |
| 2026-10-06 12:00 |
06:50:06.91 |
+30:58:55.1 |
HIP 32651 |
25.31 |
| 2026-10-07 00:00 |
06:50:12.69 |
+30:59:21.2 |
HIP 32651 |
25.96 |
| 2026-10-07 12:00 |
06:50:18.24 |
+30:59:47.8 |
HIP 32651 |
26.60 |
| 2026-10-08 00:00 |
06:50:23.55 |
+31:00:14.6 |
HIP 32651 |
27.25 |
| 2026-10-08 12:00 |
06:50:28.63 |
+31:00:41.8 |
HIP 32651 |
27.89 |
| 2026-10-09 00:00 |
06:50:33.46 |
+31:01:09.3 |
HIP 32651 |
28.52 |
| 2026-10-09 12:00 |
06:50:38.06 |
+31:01:37.2 |
HIP 32651 |
29.13 |
| 2026-10-10 00:00 |
06:50:42.42 |
+31:02:05.3 |
HIP 32651 |
29.72 |
| 2026-10-10 12:00 |
06:50:46.53 |
+31:02:33.8 |
HIP 32651 |
30.29 |
| 2026-10-11 00:00 |
06:50:50.40 |
+31:03:02.7 |
HIP 32651 |
30.83 |
| 2026-10-11 12:00 |
06:50:54.03 |
+31:03:31.8 |
HIP 32651 |
31.33 |
| 2026-10-12 00:00 |
06:50:57.41 |
+31:04:01.3 |
HIP 32651 |
31.81 |
| 2026-10-12 12:00 |
06:51:00.55 |
+31:04:31.1 |
HIP 32651 |
32.25 |
| 2026-10-13 00:00 |
06:51:03.44 |
+31:05:01.2 |
HIP 32651 |
32.65 |
| 2026-10-13 12:00 |
06:51:06.08 |
+31:05:31.6 |
HIP 32651 |
33.02 |
| 2026-10-14 00:00 |
06:51:08.47 |
+31:06:02.4 |
HIP 33049 |
32.85 |
| 2026-10-14 12:00 |
06:51:10.62 |
+31:06:33.4 |
HIP 33049 |
32.16 |
| 2026-10-15 00:00 |
06:51:12.51 |
+31:07:04.8 |
HIP 33049 |
31.51 |
| 2026-10-15 12:00 |
06:51:14.15 |
+31:07:36.5 |
HIP 33049 |
30.91 |
| 2026-10-16 00:00 |
06:51:15.54 |
+31:08:08.5 |
HIP 33049 |
30.34 |