| Parameter |
Value |
| Designation |
C/2001 W2 (BATTERS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2001-12-23T22:02:21.914880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:11Z |
| Obs used |
350 |
| NEO |
Yes |
| M1 |
12.100 |
| K1 |
10.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2001-12-05.0000000 |
| e |
0.94137478 |
| q (au) |
1.051065 |
| a (au) |
17.928550 |
| i (deg) |
115.913079 |
| Ω (om, deg) |
113.355852 |
| ω (w, deg) |
142.085792 |
| M (ma, deg) |
359.754377 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.657 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.657 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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) |
| 2026-09-20 00:00 |
08:33:50.23 |
-20:17:09.2 |
HIP 42022 |
13.27 |
| 2026-09-20 12:00 |
08:33:52.49 |
-20:17:40.2 |
HIP 42022 |
13.73 |
| 2026-09-21 00:00 |
08:33:54.72 |
-20:18:11.4 |
HIP 42022 |
14.21 |
| 2026-09-21 12:00 |
08:33:56.94 |
-20:18:42.6 |
HIP 42022 |
14.71 |
| 2026-09-22 00:00 |
08:33:59.12 |
-20:19:14.0 |
HIP 42022 |
15.23 |
| 2026-09-22 12:00 |
08:34:01.28 |
-20:19:45.5 |
HIP 42022 |
15.78 |
| 2026-09-23 00:00 |
08:34:03.42 |
-20:20:17.1 |
HIP 42022 |
16.33 |
| 2026-09-23 12:00 |
08:34:05.53 |
-20:20:48.8 |
HIP 42022 |
16.91 |
| 2026-09-24 00:00 |
08:34:07.62 |
-20:21:20.6 |
HIP 42022 |
17.49 |
| 2026-09-24 12:00 |
08:34:09.68 |
-20:21:52.5 |
HIP 42022 |
18.09 |
| 2026-09-25 00:00 |
08:34:11.72 |
-20:22:24.6 |
HIP 42148 |
18.16 |
| 2026-09-25 12:00 |
08:34:13.73 |
-20:22:56.7 |
HIP 42148 |
17.73 |
| 2026-09-26 00:00 |
08:34:15.72 |
-20:23:28.9 |
HIP 42148 |
17.33 |
| 2026-09-26 12:00 |
08:34:17.67 |
-20:24:01.2 |
HIP 42148 |
16.95 |
| 2026-09-27 00:00 |
08:34:19.61 |
-20:24:33.6 |
HIP 42148 |
16.61 |
| 2026-09-27 12:00 |
08:34:21.51 |
-20:25:06.1 |
HIP 42148 |
16.29 |
| 2026-09-28 00:00 |
08:34:23.39 |
-20:25:38.7 |
HIP 42148 |
16.00 |
| 2026-09-28 12:00 |
08:34:25.25 |
-20:26:11.3 |
HIP 42148 |
15.75 |
| 2026-09-29 00:00 |
08:34:27.07 |
-20:26:44.1 |
HIP 42148 |
15.52 |
| 2026-09-29 12:00 |
08:34:28.87 |
-20:27:16.9 |
HIP 42148 |
15.34 |
| 2026-09-30 00:00 |
08:34:30.65 |
-20:27:49.8 |
HIP 42148 |
15.18 |
| 2026-09-30 12:00 |
08:34:32.39 |
-20:28:22.8 |
HIP 42148 |
15.07 |
| 2026-10-01 00:00 |
08:34:34.11 |
-20:28:55.9 |
HIP 42148 |
14.99 |
| 2026-10-01 12:00 |
08:34:35.80 |
-20:29:29.0 |
HIP 42148 |
14.95 |
| 2026-10-02 00:00 |
08:34:37.47 |
-20:30:02.2 |
HIP 42148 |
14.94 |
| 2026-10-02 12:00 |
08:34:39.10 |
-20:30:35.5 |
HIP 42148 |
14.97 |
| 2026-10-03 00:00 |
08:34:40.71 |
-20:31:08.9 |
HIP 42148 |
15.04 |
| 2026-10-03 12:00 |
08:34:42.29 |
-20:31:42.3 |
HIP 42148 |
15.14 |
| 2026-10-04 00:00 |
08:34:43.84 |
-20:32:15.8 |
HIP 42148 |
15.28 |
| 2026-10-04 12:00 |
08:34:45.36 |
-20:32:49.3 |
HIP 42148 |
15.45 |
| 2026-10-05 00:00 |
08:34:46.86 |
-20:33:22.9 |
HIP 42148 |
15.65 |
| 2026-10-05 12:00 |
08:34:48.32 |
-20:33:56.5 |
HIP 42148 |
15.88 |
| 2026-10-06 00:00 |
08:34:49.76 |
-20:34:30.2 |
HIP 42148 |
16.14 |
| 2026-10-06 12:00 |
08:34:51.17 |
-20:35:04.0 |
HIP 42148 |
16.42 |
| 2026-10-07 00:00 |
08:34:52.54 |
-20:35:37.8 |
HIP 42148 |
16.73 |
| 2026-10-07 12:00 |
08:34:53.89 |
-20:36:11.6 |
HIP 42148 |
17.07 |
| 2026-10-08 00:00 |
08:34:55.21 |
-20:36:45.5 |
HIP 42148 |
17.42 |
| 2026-10-08 12:00 |
08:34:56.50 |
-20:37:19.4 |
HIP 42148 |
17.79 |
| 2026-10-09 00:00 |
08:34:57.76 |
-20:37:53.4 |
HIP 42148 |
18.19 |
| 2026-10-09 12:00 |
08:34:58.99 |
-20:38:27.4 |
HIP 42148 |
18.59 |
| 2026-10-10 00:00 |
08:35:00.19 |
-20:39:01.4 |
HIP 42148 |
19.02 |
| 2026-10-10 12:00 |
08:35:01.36 |
-20:39:35.4 |
HIP 42148 |
19.46 |
| 2026-10-11 00:00 |
08:35:02.49 |
-20:40:09.5 |
HIP 42148 |
19.91 |