490P/ATLAS
| 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) |
| 2026-02-03 00:00 |
03:36:00.10 |
+30:44:37.8 |
HIP 16872 |
27.03 |
| 2026-02-03 12:00 |
03:36:05.45 |
+30:43:09.4 |
HIP 16872 |
27.73 |
| 2026-02-04 00:00 |
03:36:11.06 |
+30:41:42.2 |
HIP 16872 |
28.48 |
| 2026-02-04 12:00 |
03:36:16.94 |
+30:40:16.2 |
HIP 16872 |
29.30 |
| 2026-02-05 00:00 |
03:36:23.09 |
+30:38:51.4 |
HIP 16872 |
30.18 |
| 2026-02-05 12:00 |
03:36:29.51 |
+30:37:27.7 |
HIP 16872 |
31.12 |
| 2026-02-06 00:00 |
03:36:36.20 |
+30:36:05.2 |
HIP 16872 |
32.13 |
| 2026-02-06 12:00 |
03:36:43.15 |
+30:34:43.9 |
HIP 16872 |
33.19 |
| 2026-02-07 00:00 |
03:36:50.36 |
+30:33:23.8 |
HIP 16872 |
34.31 |
| 2026-02-07 12:00 |
03:36:57.84 |
+30:32:04.8 |
HIP 16795 |
34.57 |
| 2026-02-08 00:00 |
03:37:05.57 |
+30:30:47.0 |
HIP 16795 |
33.87 |
| 2026-02-08 12:00 |
03:37:13.56 |
+30:29:30.3 |
HIP 16795 |
33.33 |
| 2026-02-09 00:00 |
03:37:21.80 |
+30:28:14.8 |
HIP 16795 |
32.97 |
| 2026-02-09 12:00 |
03:37:30.30 |
+30:27:00.5 |
HIP 16795 |
32.79 |
| 2026-02-10 00:00 |
03:37:39.05 |
+30:25:47.3 |
HIP 16795 |
32.81 |
| 2026-02-10 12:00 |
03:37:48.06 |
+30:24:35.3 |
HIP 16795 |
33.04 |
| 2026-02-11 00:00 |
03:37:57.31 |
+30:23:24.4 |
HIP 16795 |
33.47 |
| 2026-02-11 12:00 |
03:38:06.81 |
+30:22:14.7 |
HIP 16795 |
34.10 |
| 2026-02-12 00:00 |
03:38:16.55 |
+30:21:06.0 |
HIP 16795 |
34.94 |
| 2026-02-12 12:00 |
03:38:26.54 |
+30:19:58.6 |
HIP 17151 |
34.04 |
| 2026-02-13 00:00 |
03:38:36.77 |
+30:18:52.2 |
HIP 17151 |
31.66 |
| 2026-02-13 12:00 |
03:38:47.24 |
+30:17:47.0 |
HIP 17151 |
29.27 |
| 2026-02-14 00:00 |
03:38:57.95 |
+30:16:42.9 |
HIP 17151 |
26.88 |
| 2026-02-14 12:00 |
03:39:08.90 |
+30:15:39.9 |
HIP 17151 |
24.50 |
| 2026-02-15 00:00 |
03:39:20.08 |
+30:14:38.0 |
HIP 17151 |
22.15 |
| 2026-02-15 12:00 |
03:39:31.50 |
+30:13:37.3 |
HIP 17151 |
19.86 |
| 2026-02-16 00:00 |
03:39:43.15 |
+30:12:37.6 |
HIP 17151 |
17.66 |
| 2026-02-16 12:00 |
03:39:55.03 |
+30:11:39.0 |
HIP 17151 |
15.62 |
| 2026-02-17 00:00 |
03:40:07.14 |
+30:10:41.5 |
HIP 17151 |
13.83 |
| 2026-02-17 12:00 |
03:40:19.47 |
+30:09:45.1 |
HIP 17151 |
12.43 |
| 2026-02-18 00:00 |
03:40:32.03 |
+30:08:49.8 |
HIP 17151 |
11.59 |
| 2026-02-18 12:00 |
03:40:44.82 |
+30:07:55.5 |
HIP 17151 |
11.46 |
| 2026-02-19 00:00 |
03:40:57.82 |
+30:07:02.3 |
HIP 17151 |
12.10 |
| 2026-02-19 12:00 |
03:41:11.05 |
+30:06:10.1 |
HIP 17151 |
13.42 |
| 2026-02-20 00:00 |
03:41:24.49 |
+30:05:19.0 |
HIP 17151 |
15.27 |
| 2026-02-20 12:00 |
03:41:38.15 |
+30:04:29.0 |
HIP 17151 |
17.51 |
| 2026-02-21 00:00 |
03:41:52.03 |
+30:03:40.0 |
HIP 17151 |
20.02 |
| 2026-02-21 12:00 |
03:42:06.11 |
+30:02:52.0 |
HIP 17151 |
22.73 |
| 2026-02-22 00:00 |
03:42:20.41 |
+30:02:05.0 |
HIP 17151 |
25.59 |
| 2026-02-22 12:00 |
03:42:34.92 |
+30:01:19.0 |
HIP 17423 |
27.16 |
| 2026-02-23 00:00 |
03:42:49.63 |
+30:00:34.1 |
HIP 17423 |
24.56 |
| 2026-02-23 12:00 |
03:43:04.55 |
+29:59:50.1 |
HIP 17423 |
22.13 |
| 2026-02-24 00:00 |
03:43:19.68 |
+29:59:07.2 |
HIP 17423 |
19.95 |