| Parameter |
Value |
| Designation |
221P/LINEAR |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2009-01-24T08:32:46.219200Z |
| Orbit solution date (soln_date, UTC) |
2022-10-28T22:13:13Z |
| Obs used |
627 |
| NEO |
- |
| M1 |
14.000 |
| K1 |
13.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-08-08.0000000 |
| e |
0.48757555 |
| q (au) |
1.779766 |
| a (au) |
3.473226 |
| i (deg) |
11.431021 |
| Ω (om, deg) |
229.989314 |
| ω (w, deg) |
39.511181 |
| M (ma, deg) |
140.944591 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.562 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.562 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.891 |
| k |
0.999 |
| 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) |
| 2026-06-01 00:00 |
07:19:30.41 |
+13:29:22.9 |
HIP 35501 |
27.30 |
| 2026-06-01 12:00 |
07:19:55.47 |
+13:28:58.6 |
HIP 35501 |
28.01 |
| 2026-06-02 00:00 |
07:20:20.62 |
+13:28:33.5 |
HIP 35646 |
23.76 |
| 2026-06-02 12:00 |
07:20:45.85 |
+13:28:07.9 |
HIP 35646 |
20.15 |
| 2026-06-03 00:00 |
07:21:11.16 |
+13:27:41.5 |
HIP 35646 |
17.97 |
| 2026-06-03 12:00 |
07:21:36.55 |
+13:27:14.4 |
HIP 35646 |
17.77 |
| 2026-06-04 00:00 |
07:22:02.02 |
+13:26:46.7 |
HIP 35646 |
19.62 |
| 2026-06-04 12:00 |
07:22:27.56 |
+13:26:18.2 |
HIP 35812 |
22.64 |
| 2026-06-05 00:00 |
07:22:53.18 |
+13:25:49.1 |
HIP 35812 |
20.13 |
| 2026-06-05 12:00 |
07:23:18.88 |
+13:25:19.3 |
HIP 35812 |
19.38 |
| 2026-06-06 00:00 |
07:23:44.65 |
+13:24:48.8 |
HIP 35812 |
20.61 |
| 2026-06-06 12:00 |
07:24:10.50 |
+13:24:17.6 |
HIP 35812 |
23.52 |
| 2026-06-07 00:00 |
07:24:36.42 |
+13:23:45.7 |
HIP 35812 |
27.59 |
| 2026-06-07 12:00 |
07:25:02.41 |
+13:23:13.2 |
HIP 36153 |
29.31 |
| 2026-06-08 00:00 |
07:25:28.48 |
+13:22:39.9 |
HIP 36153 |
23.83 |
| 2026-06-08 12:00 |
07:25:54.61 |
+13:22:05.9 |
HIP 36153 |
18.92 |
| 2026-06-09 00:00 |
07:26:20.82 |
+13:21:31.3 |
HIP 36153 |
15.14 |
| 2026-06-09 12:00 |
07:26:47.10 |
+13:20:55.9 |
HIP 36153 |
13.52 |
| 2026-06-10 00:00 |
07:27:13.45 |
+13:20:19.9 |
HIP 36153 |
14.80 |
| 2026-06-10 12:00 |
07:27:39.87 |
+13:19:43.2 |
HIP 36153 |
18.41 |
| 2026-06-11 00:00 |
07:28:06.36 |
+13:19:05.7 |
HIP 36153 |
23.30 |
| 2026-06-11 12:00 |
07:28:32.91 |
+13:18:27.6 |
HIP 36153 |
28.84 |
| 2026-06-12 00:00 |
07:28:59.53 |
+13:17:48.8 |
HIP 36371 |
32.34 |
| 2026-06-12 12:00 |
07:29:26.22 |
+13:17:09.2 |
HIP 36371 |
31.76 |
| 2026-06-13 00:00 |
07:29:52.97 |
+13:16:29.0 |
HIP 36371 |
32.50 |
| 2026-06-13 12:00 |
07:30:19.78 |
+13:15:48.1 |
HIP 36371 |
34.49 |
| 2026-06-14 00:00 |
07:30:46.66 |
+13:15:06.4 |
HIP 36709 |
33.39 |
| 2026-06-14 12:00 |
07:31:13.60 |
+13:14:24.1 |
HIP 36709 |
26.80 |
| 2026-06-15 00:00 |
07:31:40.60 |
+13:13:41.1 |
HIP 36709 |
20.19 |
| 2026-06-15 12:00 |
07:32:07.67 |
+13:12:57.4 |
HIP 36709 |
13.57 |
| 2026-06-16 00:00 |
07:32:34.79 |
+13:12:12.9 |
HIP 36709 |
6.93 |
| 2026-06-16 12:00 |
07:33:01.97 |
+13:11:27.8 |
HIP 36709 |
0.40 |
| 2026-06-17 00:00 |
07:33:29.21 |
+13:10:41.9 |
HIP 36709 |
6.42 |
| 2026-06-17 12:00 |
07:33:56.51 |
+13:09:55.4 |
HIP 36709 |
13.11 |
| 2026-06-18 00:00 |
07:34:23.86 |
+13:09:08.2 |
HIP 36771 |
17.74 |
| 2026-06-18 12:00 |
07:34:51.27 |
+13:08:20.3 |
HIP 36771 |
22.42 |
| 2026-06-19 00:00 |
07:35:18.73 |
+13:07:31.6 |
HIP 37045 |
26.36 |
| 2026-06-19 12:00 |
07:35:46.25 |
+13:06:42.3 |
HIP 37045 |
20.74 |
| 2026-06-20 00:00 |
07:36:13.82 |
+13:05:52.3 |
HIP 37045 |
15.99 |
| 2026-06-20 12:00 |
07:36:41.44 |
+13:05:01.6 |
HIP 37045 |
13.14 |
| 2026-06-21 00:00 |
07:37:09.12 |
+13:04:10.2 |
HIP 37045 |
13.47 |
| 2026-06-21 12:00 |
07:37:36.84 |
+13:03:18.1 |
HIP 37147 |
16.30 |
| 2026-06-22 00:00 |
07:38:04.61 |
+13:02:25.3 |
HIP 37147 |
14.36 |