| Parameter |
Value |
| Designation |
478P/ATLAS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2024-05-01T18:15:32.791680Z |
| Orbit solution date (soln_date, UTC) |
2024-10-10T17:58:36Z |
| Obs used |
494 |
| NEO |
- |
| M1 |
10.000 |
| K1 |
19.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2017-01-28T11:47:24Z |
| Discovery magnitude (MPC) |
20.80 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-08-06.0000000 |
| e |
0.34362489 |
| q (au) |
2.394062 |
| a (au) |
3.647398 |
| i (deg) |
12.523311 |
| Ω (om, deg) |
127.279868 |
| ω (w, deg) |
13.107152 |
| M (ma, deg) |
321.831235 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.334 + 5.191\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.334 |
| n |
5.191 |
| gf |
0.938 |
| gb |
-0.669 |
| k |
0.800 |
| δ90 |
1.335 |
| 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 |
19:22:12.76 |
-14:52:51.1 |
HIP 95266 |
38.84 |
| 2026-05-12 12:00 |
19:22:08.49 |
-14:52:52.7 |
HIP 95266 |
39.16 |
| 2026-05-13 00:00 |
19:22:03.97 |
-14:52:55.0 |
HIP 95266 |
39.54 |
| 2026-05-13 12:00 |
19:21:59.21 |
-14:52:58.1 |
HIP 95266 |
39.98 |
| 2026-05-14 00:00 |
19:21:54.21 |
-14:53:01.9 |
HIP 95266 |
40.48 |
| 2026-05-14 12:00 |
19:21:48.96 |
-14:53:06.5 |
HIP 95175 |
41.04 |
| 2026-05-15 00:00 |
19:21:43.47 |
-14:53:11.8 |
HIP 95175 |
40.92 |
| 2026-05-15 12:00 |
19:21:37.73 |
-14:53:17.9 |
HIP 95175 |
40.84 |
| 2026-05-16 00:00 |
19:21:31.75 |
-14:53:24.8 |
HIP 95175 |
40.80 |
| 2026-05-16 12:00 |
19:21:25.53 |
-14:53:32.4 |
HIP 95175 |
40.81 |
| 2026-05-17 00:00 |
19:21:19.07 |
-14:53:40.8 |
HIP 95175 |
40.86 |
| 2026-05-17 12:00 |
19:21:12.37 |
-14:53:49.9 |
HIP 95175 |
40.98 |
| 2026-05-18 00:00 |
19:21:05.42 |
-14:53:59.8 |
HIP 95175 |
41.15 |
| 2026-05-18 12:00 |
19:20:58.24 |
-14:54:10.5 |
HIP 95175 |
41.40 |
| 2026-05-19 00:00 |
19:20:50.82 |
-14:54:22.0 |
HIP 95175 |
41.72 |
| 2026-05-19 12:00 |
19:20:43.16 |
-14:54:34.2 |
HIP 95175 |
42.13 |
| 2026-05-20 00:00 |
19:20:35.27 |
-14:54:47.2 |
HIP 95175 |
42.62 |
| 2026-05-20 12:00 |
19:20:27.14 |
-14:55:01.0 |
HIP 94929 |
42.65 |
| 2026-05-21 00:00 |
19:20:18.78 |
-14:55:15.6 |
HIP 94929 |
41.48 |
| 2026-05-21 12:00 |
19:20:10.19 |
-14:55:30.9 |
HIP 94929 |
40.34 |
| 2026-05-22 00:00 |
19:20:01.36 |
-14:55:47.1 |
HIP 94929 |
39.25 |
| 2026-05-22 12:00 |
19:19:52.30 |
-14:56:04.0 |
HIP 94929 |
38.22 |
| 2026-05-23 00:00 |
19:19:43.01 |
-14:56:21.7 |
HIP 94929 |
37.26 |
| 2026-05-23 12:00 |
19:19:33.50 |
-14:56:40.1 |
HIP 94929 |
36.38 |
| 2026-05-24 00:00 |
19:19:23.76 |
-14:56:59.4 |
HIP 94929 |
35.62 |
| 2026-05-24 12:00 |
19:19:13.79 |
-14:57:19.4 |
HIP 94929 |
34.98 |
| 2026-05-25 00:00 |
19:19:03.60 |
-14:57:40.2 |
HIP 94929 |
34.49 |
| 2026-05-25 12:00 |
19:18:53.18 |
-14:58:01.8 |
HIP 94929 |
34.17 |
| 2026-05-26 00:00 |
19:18:42.54 |
-14:58:24.1 |
HIP 94807 |
33.55 |
| 2026-05-26 12:00 |
19:18:31.69 |
-14:58:47.2 |
HIP 94807 |
32.56 |
| 2026-05-27 00:00 |
19:18:20.61 |
-14:59:11.1 |
HIP 94807 |
31.75 |
| 2026-05-27 12:00 |
19:18:09.32 |
-14:59:35.8 |
HIP 94807 |
31.15 |
| 2026-05-28 00:00 |
19:17:57.80 |
-15:00:01.3 |
HIP 94807 |
30.79 |
| 2026-05-28 12:00 |
19:17:46.08 |
-15:00:27.5 |
HIP 94807 |
30.68 |
| 2026-05-29 00:00 |
19:17:34.14 |
-15:00:54.5 |
HIP 94657 |
29.01 |
| 2026-05-29 12:00 |
19:17:21.99 |
-15:01:22.2 |
HIP 94657 |
26.50 |
| 2026-05-30 00:00 |
19:17:09.63 |
-15:01:50.7 |
HIP 94657 |
24.04 |
| 2026-05-30 12:00 |
19:16:57.06 |
-15:02:20.0 |
HIP 94657 |
21.70 |
| 2026-05-31 00:00 |
19:16:44.28 |
-15:02:50.0 |
HIP 94657 |
19.53 |
| 2026-05-31 12:00 |
19:16:31.30 |
-15:03:20.8 |
HIP 94657 |
17.63 |
| 2026-06-01 00:00 |
19:16:18.11 |
-15:03:52.4 |
HIP 94657 |
16.11 |
| 2026-06-01 12:00 |
19:16:04.72 |
-15:04:24.7 |
HIP 94657 |
15.14 |
| 2026-06-02 00:00 |
19:15:51.13 |
-15:04:57.8 |
HIP 94657 |
14.85 |