| Parameter |
Value |
| Designation |
C/2011 Q4 (SWAN) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2011-09-21T02:00:10.520640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:56Z |
| Obs used |
168 |
| NEO |
- |
| M1 |
11.700 |
| K1 |
9.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-11-05.0000000 |
| e |
0.97415823 |
| q (au) |
1.112227 |
| a (au) |
43.039904 |
| i (deg) |
147.843070 |
| Ω (om, deg) |
252.085709 |
| ω (w, deg) |
1.880850 |
| M (ma, deg) |
0.156785 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.419 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.419 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.663 |
| k |
0.800 |
| 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 |
05:45:22.11 |
+31:33:31.3 |
HIP 27164 |
14.12 |
| 2026-07-29 12:00 |
05:45:25.32 |
+31:33:36.0 |
HIP 27164 |
14.14 |
| 2026-07-30 00:00 |
05:45:28.52 |
+31:33:40.8 |
HIP 27164 |
14.19 |
| 2026-07-30 12:00 |
05:45:31.69 |
+31:33:45.6 |
HIP 27164 |
14.28 |
| 2026-07-31 00:00 |
05:45:34.84 |
+31:33:50.5 |
HIP 27164 |
14.39 |
| 2026-07-31 12:00 |
05:45:37.96 |
+31:33:55.4 |
HIP 27164 |
14.54 |
| 2026-08-01 00:00 |
05:45:41.06 |
+31:34:00.3 |
HIP 27164 |
14.72 |
| 2026-08-01 12:00 |
05:45:44.14 |
+31:34:05.3 |
HIP 27164 |
14.92 |
| 2026-08-02 00:00 |
05:45:47.19 |
+31:34:10.3 |
HIP 27164 |
15.15 |
| 2026-08-02 12:00 |
05:45:50.22 |
+31:34:15.4 |
HIP 27164 |
15.41 |
| 2026-08-03 00:00 |
05:45:53.22 |
+31:34:20.5 |
HIP 27164 |
15.68 |
| 2026-08-03 12:00 |
05:45:56.20 |
+31:34:25.6 |
HIP 27164 |
15.98 |
| 2026-08-04 00:00 |
05:45:59.16 |
+31:34:30.8 |
HIP 27164 |
16.29 |
| 2026-08-04 12:00 |
05:46:02.08 |
+31:34:36.0 |
HIP 27164 |
16.62 |
| 2026-08-05 00:00 |
05:46:04.99 |
+31:34:41.2 |
HIP 27164 |
16.97 |
| 2026-08-05 12:00 |
05:46:07.86 |
+31:34:46.5 |
HIP 27164 |
17.33 |
| 2026-08-06 00:00 |
05:46:10.71 |
+31:34:51.8 |
HIP 27164 |
17.70 |
| 2026-08-06 12:00 |
05:46:13.54 |
+31:34:57.2 |
HIP 27164 |
18.08 |
| 2026-08-07 00:00 |
05:46:16.34 |
+31:35:02.6 |
HIP 27164 |
18.47 |
| 2026-08-07 12:00 |
05:46:19.11 |
+31:35:08.0 |
HIP 27164 |
18.87 |
| 2026-08-08 00:00 |
05:46:21.85 |
+31:35:13.5 |
HIP 27164 |
19.28 |
| 2026-08-08 12:00 |
05:46:24.57 |
+31:35:19.0 |
HIP 27164 |
19.69 |
| 2026-08-09 00:00 |
05:46:27.26 |
+31:35:24.5 |
HIP 27164 |
20.11 |
| 2026-08-09 12:00 |
05:46:29.92 |
+31:35:30.1 |
HIP 27164 |
20.54 |
| 2026-08-10 00:00 |
05:46:32.55 |
+31:35:35.7 |
HIP 27164 |
20.97 |
| 2026-08-10 12:00 |
05:46:35.16 |
+31:35:41.4 |
HIP 27164 |
21.40 |
| 2026-08-11 00:00 |
05:46:37.74 |
+31:35:47.0 |
HIP 27164 |
21.83 |
| 2026-08-11 12:00 |
05:46:40.29 |
+31:35:52.8 |
HIP 27164 |
22.27 |
| 2026-08-12 00:00 |
05:46:42.80 |
+31:35:58.5 |
HIP 27164 |
22.70 |
| 2026-08-12 12:00 |
05:46:45.30 |
+31:36:04.3 |
HIP 27164 |
23.14 |
| 2026-08-13 00:00 |
05:46:47.76 |
+31:36:10.1 |
HIP 27164 |
23.58 |
| 2026-08-13 12:00 |
05:46:50.19 |
+31:36:15.9 |
HIP 27164 |
24.01 |
| 2026-08-14 00:00 |
05:46:52.59 |
+31:36:21.8 |
HIP 27164 |
24.45 |
| 2026-08-14 12:00 |
05:46:54.96 |
+31:36:27.7 |
HIP 27164 |
24.89 |
| 2026-08-15 00:00 |
05:46:57.30 |
+31:36:33.6 |
HIP 27164 |
25.32 |
| 2026-08-15 12:00 |
05:46:59.61 |
+31:36:39.6 |
HIP 27164 |
25.75 |
| 2026-08-16 00:00 |
05:47:01.89 |
+31:36:45.6 |
HIP 27164 |
26.18 |
| 2026-08-16 12:00 |
05:47:04.14 |
+31:36:51.6 |
HIP 27164 |
26.61 |
| 2026-08-17 00:00 |
05:47:06.36 |
+31:36:57.7 |
HIP 27164 |
27.04 |
| 2026-08-17 12:00 |
05:47:08.55 |
+31:37:03.8 |
HIP 27164 |
27.46 |
| 2026-08-18 00:00 |
05:47:10.70 |
+31:37:09.9 |
HIP 27164 |
27.88 |
| 2026-08-18 12:00 |
05:47:12.83 |
+31:37:16.0 |
HIP 27164 |
28.29 |
| 2026-08-19 00:00 |
05:47:14.92 |
+31:37:22.2 |
HIP 27164 |
28.70 |