C/2017 D3 (ATLAS)
| Parameter |
Value |
| Designation |
C/2017 D3 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-04-26T17:48:37.664640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:30Z |
| Obs used |
523 |
| NEO |
- |
| M1 |
11.100 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-10-06.0000000 |
| e |
1.00243639 |
| q (au) |
4.971286 |
| a (au) |
-2040.429612 |
| i (deg) |
125.570039 |
| Ω (om, deg) |
186.618173 |
| ω (w, deg) |
340.767499 |
| M (ma, deg) |
0.001735 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.067 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.067 |
| n |
2.000 |
| gf |
0.999 |
| gb |
-1.000 |
| k |
1.000 |
| δ90 |
9.999 |
| 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 |
03:21:05.07 |
+75:22:46.9 |
HIP 15516 |
9.56 |
| 2026-02-03 12:00 |
03:20:59.05 |
+75:21:20.2 |
HIP 15516 |
8.11 |
| 2026-02-04 00:00 |
03:20:53.26 |
+75:19:53.4 |
HIP 15516 |
6.68 |
| 2026-02-04 12:00 |
03:20:47.68 |
+75:18:26.8 |
HIP 15516 |
5.29 |
| 2026-02-05 00:00 |
03:20:42.33 |
+75:17:00.2 |
HIP 15516 |
3.99 |
| 2026-02-05 12:00 |
03:20:37.19 |
+75:15:33.7 |
HIP 15516 |
2.88 |
| 2026-02-06 00:00 |
03:20:32.27 |
+75:14:07.3 |
HIP 15516 |
2.26 |
| 2026-02-06 12:00 |
03:20:27.57 |
+75:12:41.0 |
HIP 15516 |
2.51 |
| 2026-02-07 00:00 |
03:20:23.09 |
+75:11:14.8 |
HIP 15516 |
3.44 |
| 2026-02-07 12:00 |
03:20:18.82 |
+75:09:48.7 |
HIP 15516 |
4.66 |
| 2026-02-08 00:00 |
03:20:14.76 |
+75:08:22.7 |
HIP 15516 |
5.99 |
| 2026-02-08 12:00 |
03:20:10.92 |
+75:06:56.8 |
HIP 15516 |
7.36 |
| 2026-02-09 00:00 |
03:20:07.28 |
+75:05:31.1 |
HIP 15516 |
8.76 |
| 2026-02-09 12:00 |
03:20:03.86 |
+75:04:05.5 |
HIP 15516 |
10.17 |
| 2026-02-10 00:00 |
03:20:00.65 |
+75:02:40.0 |
HIP 15516 |
11.59 |
| 2026-02-10 12:00 |
03:19:57.65 |
+75:01:14.7 |
HIP 15516 |
13.01 |
| 2026-02-11 00:00 |
03:19:54.85 |
+74:59:49.5 |
HIP 15516 |
14.43 |
| 2026-02-11 12:00 |
03:19:52.26 |
+74:58:24.5 |
HIP 15516 |
15.85 |
| 2026-02-12 00:00 |
03:19:49.87 |
+74:56:59.7 |
HIP 15516 |
17.26 |
| 2026-02-12 12:00 |
03:19:47.69 |
+74:55:35.0 |
HIP 15516 |
18.68 |
| 2026-02-13 00:00 |
03:19:45.71 |
+74:54:10.6 |
HIP 15516 |
20.09 |
| 2026-02-13 12:00 |
03:19:43.93 |
+74:52:46.3 |
HIP 15516 |
21.50 |
| 2026-02-14 00:00 |
03:19:42.35 |
+74:51:22.2 |
HIP 15516 |
22.90 |
| 2026-02-14 12:00 |
03:19:40.98 |
+74:49:58.3 |
HIP 15516 |
24.30 |
| 2026-02-15 00:00 |
03:19:39.80 |
+74:48:34.6 |
HIP 15516 |
25.70 |
| 2026-02-15 12:00 |
03:19:38.81 |
+74:47:11.1 |
HIP 15516 |
27.09 |
| 2026-02-16 00:00 |
03:19:38.03 |
+74:45:47.9 |
HIP 15516 |
28.48 |
| 2026-02-16 12:00 |
03:19:37.43 |
+74:44:24.8 |
HIP 14948 |
29.58 |
| 2026-02-17 00:00 |
03:19:37.03 |
+74:43:02.0 |
HIP 14948 |
30.15 |
| 2026-02-17 12:00 |
03:19:36.83 |
+74:41:39.4 |
HIP 14948 |
30.78 |
| 2026-02-18 00:00 |
03:19:36.81 |
+74:40:17.1 |
HIP 14948 |
31.47 |
| 2026-02-18 12:00 |
03:19:36.98 |
+74:38:55.0 |
HIP 14948 |
32.21 |
| 2026-02-19 00:00 |
03:19:37.34 |
+74:37:33.2 |
HIP 15073 |
31.44 |
| 2026-02-19 12:00 |
03:19:37.89 |
+74:36:11.6 |
HIP 15073 |
30.50 |
| 2026-02-20 00:00 |
03:19:38.63 |
+74:34:50.3 |
HIP 15073 |
29.60 |
| 2026-02-20 12:00 |
03:19:39.54 |
+74:33:29.3 |
HIP 15073 |
28.75 |
| 2026-02-21 00:00 |
03:19:40.65 |
+74:32:08.5 |
HIP 15073 |
27.96 |
| 2026-02-21 12:00 |
03:19:41.93 |
+74:30:48.0 |
HIP 15843 |
27.09 |
| 2026-02-22 00:00 |
03:19:43.39 |
+74:29:27.8 |
HIP 15843 |
26.03 |
| 2026-02-22 12:00 |
03:19:45.03 |
+74:28:07.9 |
HIP 15843 |
25.00 |
| 2026-02-23 00:00 |
03:19:46.85 |
+74:26:48.3 |
HIP 15843 |
23.99 |
| 2026-02-23 12:00 |
03:19:48.85 |
+74:25:29.0 |
HIP 15843 |
23.01 |
| 2026-02-24 00:00 |
03:19:51.02 |
+74:24:10.0 |
HIP 15843 |
22.05 |