| Parameter |
Value |
| Designation |
C/2015 V2 (Johnson) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-06-12T08:20:20.379840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:16Z |
| Obs used |
5886 |
| NEO |
- |
| M1 |
10.000 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-01-18.0000000 |
| e |
1.00170268 |
| q (au) |
1.636950 |
| a (au) |
-961.396893 |
| i (deg) |
49.874813 |
| Ω (om, deg) |
69.852102 |
| ω (w, deg) |
164.898092 |
| M (ma, deg) |
-0.004806 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.183 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.183 |
| n |
2.000 |
| gf |
0.999 |
| gb |
-0.781 |
| 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 |
| 2015-01-11 |
2017-06-11 |
+1.6631 |
-1.343 |
| 2017-06-12 |
2017-08-29 |
-9.8516 |
+0.988 |
| 2017-08-29 |
2019-10-27 |
+2.9922 |
-2.101 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
03:02:41.68 |
-16:43:39.3 |
HIP 14101 |
14.47 |
| 2026-06-01 12:00 |
03:02:46.49 |
-16:43:34.2 |
HIP 14101 |
15.39 |
| 2026-06-02 00:00 |
03:02:51.29 |
-16:43:29.5 |
HIP 14101 |
16.35 |
| 2026-06-02 12:00 |
03:02:56.07 |
-16:43:25.1 |
HIP 14101 |
17.32 |
| 2026-06-03 00:00 |
03:03:00.83 |
-16:43:21.2 |
HIP 14101 |
18.32 |
| 2026-06-03 12:00 |
03:03:05.58 |
-16:43:17.6 |
HIP 14101 |
19.33 |
| 2026-06-04 00:00 |
03:03:10.31 |
-16:43:14.3 |
HIP 14101 |
20.35 |
| 2026-06-04 12:00 |
03:03:15.02 |
-16:43:11.5 |
HIP 14101 |
21.39 |
| 2026-06-05 00:00 |
03:03:19.71 |
-16:43:09.0 |
HIP 14101 |
22.43 |
| 2026-06-05 12:00 |
03:03:24.39 |
-16:43:06.9 |
HIP 14101 |
23.47 |
| 2026-06-06 00:00 |
03:03:29.05 |
-16:43:05.1 |
HIP 14101 |
24.52 |
| 2026-06-06 12:00 |
03:03:33.70 |
-16:43:03.7 |
HIP 14101 |
25.58 |
| 2026-06-07 00:00 |
03:03:38.32 |
-16:43:02.8 |
HIP 14101 |
26.63 |
| 2026-06-07 12:00 |
03:03:42.93 |
-16:43:02.1 |
HIP 14380 |
26.79 |
| 2026-06-08 00:00 |
03:03:47.51 |
-16:43:01.9 |
HIP 14380 |
25.73 |
| 2026-06-08 12:00 |
03:03:52.08 |
-16:43:02.0 |
HIP 14380 |
24.67 |
| 2026-06-09 00:00 |
03:03:56.63 |
-16:43:02.5 |
HIP 14380 |
23.63 |
| 2026-06-09 12:00 |
03:04:01.16 |
-16:43:03.4 |
HIP 14380 |
22.59 |
| 2026-06-10 00:00 |
03:04:05.67 |
-16:43:04.6 |
HIP 14380 |
21.57 |
| 2026-06-10 12:00 |
03:04:10.16 |
-16:43:06.2 |
HIP 14380 |
20.55 |
| 2026-06-11 00:00 |
03:04:14.62 |
-16:43:08.2 |
HIP 14380 |
19.56 |
| 2026-06-11 12:00 |
03:04:19.07 |
-16:43:10.6 |
HIP 14380 |
18.57 |
| 2026-06-12 00:00 |
03:04:23.50 |
-16:43:13.3 |
HIP 14380 |
17.60 |
| 2026-06-12 12:00 |
03:04:27.90 |
-16:43:16.4 |
HIP 14380 |
16.66 |
| 2026-06-13 00:00 |
03:04:32.29 |
-16:43:19.9 |
HIP 14380 |
15.73 |
| 2026-06-13 12:00 |
03:04:36.65 |
-16:43:23.7 |
HIP 14380 |
14.82 |
| 2026-06-14 00:00 |
03:04:40.98 |
-16:43:28.0 |
HIP 14380 |
13.95 |
| 2026-06-14 12:00 |
03:04:45.30 |
-16:43:32.5 |
HIP 14380 |
13.10 |
| 2026-06-15 00:00 |
03:04:49.59 |
-16:43:37.5 |
HIP 14380 |
12.30 |
| 2026-06-15 12:00 |
03:04:53.86 |
-16:43:42.8 |
HIP 14380 |
11.54 |
| 2026-06-16 00:00 |
03:04:58.11 |
-16:43:48.6 |
HIP 14380 |
10.83 |
| 2026-06-16 12:00 |
03:05:02.33 |
-16:43:54.6 |
HIP 14380 |
10.18 |
| 2026-06-17 00:00 |
03:05:06.53 |
-16:44:01.1 |
HIP 14380 |
9.60 |
| 2026-06-17 12:00 |
03:05:10.70 |
-16:44:07.9 |
HIP 14380 |
9.11 |
| 2026-06-18 00:00 |
03:05:14.85 |
-16:44:15.1 |
HIP 14380 |
8.72 |
| 2026-06-18 12:00 |
03:05:18.97 |
-16:44:22.6 |
HIP 14380 |
8.43 |
| 2026-06-19 00:00 |
03:05:23.07 |
-16:44:30.5 |
HIP 14380 |
8.26 |
| 2026-06-19 12:00 |
03:05:27.14 |
-16:44:38.8 |
HIP 14380 |
8.22 |
| 2026-06-20 00:00 |
03:05:31.19 |
-16:44:47.4 |
HIP 14380 |
8.30 |
| 2026-06-20 12:00 |
03:05:35.21 |
-16:44:56.4 |
HIP 14380 |
8.50 |
| 2026-06-21 00:00 |
03:05:39.20 |
-16:45:05.8 |
HIP 14380 |
8.81 |
| 2026-06-21 12:00 |
03:05:43.17 |
-16:45:15.5 |
HIP 14380 |
9.21 |
| 2026-06-22 00:00 |
03:05:47.11 |
-16:45:25.6 |
HIP 14380 |
9.69 |