| Parameter |
Value |
| Designation |
C/2008 J1 (Boattini) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2008-07-13T06:16:45.272640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:19Z |
| Obs used |
1557 |
| NEO |
- |
| M1 |
8.700 |
| K1 |
17.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-08-03.0000000 |
| e |
0.98961635 |
| q (au) |
1.724294 |
| a (au) |
166.058556 |
| i (deg) |
61.780021 |
| Ω (om, deg) |
273.419698 |
| ω (w, deg) |
68.122712 |
| M (ma, deg) |
0.009552 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.102 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.102 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.525 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2008-05-02 |
2008-07-13 |
+2.4126 |
-0.690 |
| 2008-07-13 |
2009-04-04 |
+6.1030 |
-2.669 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
07:37:38.44 |
-16:33:34.1 |
HIP 37289 |
30.65 |
| 2026-09-20 12:00 |
07:37:39.88 |
-16:34:05.9 |
HIP 37289 |
30.07 |
| 2026-09-21 00:00 |
07:37:41.29 |
-16:34:37.8 |
HIP 37289 |
29.49 |
| 2026-09-21 12:00 |
07:37:42.68 |
-16:35:09.8 |
HIP 37289 |
28.92 |
| 2026-09-22 00:00 |
07:37:44.05 |
-16:35:41.8 |
HIP 37289 |
28.36 |
| 2026-09-22 12:00 |
07:37:45.38 |
-16:36:13.9 |
HIP 37289 |
27.80 |
| 2026-09-23 00:00 |
07:37:46.70 |
-16:36:46.1 |
HIP 37289 |
27.25 |
| 2026-09-23 12:00 |
07:37:47.99 |
-16:37:18.3 |
HIP 37289 |
26.71 |
| 2026-09-24 00:00 |
07:37:49.25 |
-16:37:50.5 |
HIP 37289 |
26.18 |
| 2026-09-24 12:00 |
07:37:50.48 |
-16:38:22.8 |
HIP 37289 |
25.66 |
| 2026-09-25 00:00 |
07:37:51.69 |
-16:38:55.2 |
HIP 37289 |
25.15 |
| 2026-09-25 12:00 |
07:37:52.88 |
-16:39:27.6 |
HIP 37289 |
24.64 |
| 2026-09-26 00:00 |
07:37:54.04 |
-16:40:00.1 |
HIP 37289 |
24.15 |
| 2026-09-26 12:00 |
07:37:55.17 |
-16:40:32.6 |
HIP 37289 |
23.67 |
| 2026-09-27 00:00 |
07:37:56.27 |
-16:41:05.1 |
HIP 37289 |
23.19 |
| 2026-09-27 12:00 |
07:37:57.35 |
-16:41:37.7 |
HIP 37289 |
22.74 |
| 2026-09-28 00:00 |
07:37:58.41 |
-16:42:10.3 |
HIP 37289 |
22.29 |
| 2026-09-28 12:00 |
07:37:59.43 |
-16:42:43.0 |
HIP 37289 |
21.85 |
| 2026-09-29 00:00 |
07:38:00.43 |
-16:43:15.7 |
HIP 37289 |
21.43 |
| 2026-09-29 12:00 |
07:38:01.41 |
-16:43:48.4 |
HIP 37289 |
21.03 |
| 2026-09-30 00:00 |
07:38:02.35 |
-16:44:21.2 |
HIP 37289 |
20.63 |
| 2026-09-30 12:00 |
07:38:03.27 |
-16:44:54.0 |
HIP 37289 |
20.26 |
| 2026-10-01 00:00 |
07:38:04.16 |
-16:45:26.8 |
HIP 37289 |
19.90 |
| 2026-10-01 12:00 |
07:38:05.03 |
-16:45:59.6 |
HIP 37289 |
19.56 |
| 2026-10-02 00:00 |
07:38:05.87 |
-16:46:32.5 |
HIP 37289 |
19.23 |
| 2026-10-02 12:00 |
07:38:06.68 |
-16:47:05.4 |
HIP 37289 |
18.93 |
| 2026-10-03 00:00 |
07:38:07.46 |
-16:47:38.3 |
HIP 37289 |
18.64 |
| 2026-10-03 12:00 |
07:38:08.22 |
-16:48:11.2 |
HIP 37289 |
18.37 |
| 2026-10-04 00:00 |
07:38:08.94 |
-16:48:44.1 |
HIP 37289 |
18.13 |
| 2026-10-04 12:00 |
07:38:09.64 |
-16:49:17.1 |
HIP 37289 |
17.91 |
| 2026-10-05 00:00 |
07:38:10.32 |
-16:49:50.0 |
HIP 37289 |
17.71 |
| 2026-10-05 12:00 |
07:38:10.96 |
-16:50:23.0 |
HIP 37289 |
17.53 |
| 2026-10-06 00:00 |
07:38:11.58 |
-16:50:55.9 |
HIP 37289 |
17.38 |
| 2026-10-06 12:00 |
07:38:12.17 |
-16:51:28.9 |
HIP 37289 |
17.25 |
| 2026-10-07 00:00 |
07:38:12.73 |
-16:52:01.9 |
HIP 37289 |
17.14 |
| 2026-10-07 12:00 |
07:38:13.26 |
-16:52:34.8 |
HIP 37289 |
17.06 |
| 2026-10-08 00:00 |
07:38:13.76 |
-16:53:07.8 |
HIP 37289 |
17.01 |
| 2026-10-08 12:00 |
07:38:14.24 |
-16:53:40.8 |
HIP 37289 |
16.98 |
| 2026-10-09 00:00 |
07:38:14.69 |
-16:54:13.7 |
HIP 37289 |
16.97 |
| 2026-10-09 12:00 |
07:38:15.11 |
-16:54:46.7 |
HIP 37289 |
16.99 |
| 2026-10-10 00:00 |
07:38:15.50 |
-16:55:19.6 |
HIP 37289 |
17.04 |
| 2026-10-10 12:00 |
07:38:15.86 |
-16:55:52.5 |
HIP 37289 |
17.11 |
| 2026-10-11 00:00 |
07:38:16.19 |
-16:56:25.4 |
HIP 37289 |
17.20 |