Bassano Bresciano Observatory Veronika … · Nov 2012 612 Veronika rotation time find out Pag.18...

Bassano Bresciano Observatory Nov 2012 612 Veronika rotation time find out Pag.1

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Summary

Assumptions ...................................................................................................................................................... 2

Initial data .......................................................................................................................................................... 2

Analysis ............................................................................................................................................................ 12

Conclusion ....................................................................................................................................................... 18

Assumptions

Discovered 08/10/1906 at Heidelberg observatory by August Kopff Semi-major axis: 3.160 UA Orbital eccentricity: 0.259 Orbital inclination: 20.831° Diameter: 37.74 Km This minor planet is reported on Minor Planet Bulletin n. 39-3 with no previous period.

Initial data

Analysis was done with measurement taken between 11/09/2012 and 16/10/2012. Observations cover 359 days span. These sessions was included


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Sessions 227 taken 11/09/2012

62 points in 2:20 hours


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Session 225 taken 13/09/2012



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Session taken 245 21/09/2012



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Analysis

A first check was done with all raw values. Session 237 was applied a delta comp = 13.5 because it wasn’t catalogue matched

Using session 245 as reference due low amplitude delta comp was assigned in order to reduce the difference


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From single night measurement period should be bimodal more than 5 hours. A first analysis was done in the range between 5 and 20 hours with step 0.01. This is period spectrum.

It show possible rotation time at: 8.3, 12.4, 16.5


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An analysis in the range between 8.0 and 9.0 hours with step 0.001 shows this phase diagram.

Good correlation


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Good correlation, too many maximum


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No good correlation.


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The best correlations is at period 8.245. This is coherent to the single night measurement showing an asymmetric bimodal curve. So we adjusted delta comps assuming as reference the sessions 245. Others sessions was adjusted running many time period finding trying different delta comp. values util RMS decrease. These was done for all sessions. Each time was found a value minimizing RMS the operation was replied on all other sessions. Process was stopped when any change in any session would make RMS greater. At the end delta comp sessions is

237 13.720 238 0.170 239 0.280 242 0.230 243 0.000 244 0.010 245 0.000 246 0.020 247 -0.140

With this phased plot.

Diagram shows 8.244 hours period.


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Conclusion

612 Veronika. It was selected from “Lightcurve Photometry opportunities: 2012 July September ” Minor Planet Bulletin 39. With no previous period reported. It was been observed for 8 nights covering 35 days span. Three sessions was longer than 5 hours, all these show very asymmetric period not totally covered. Period spectrum analysis has a only big deep peak It give a period P = 8.244 ± 0.001 hours with amplitude A = 0.14 ± 0.02 Mag.

Bassano Bresciano Observatory Veronika … · Nov 2012 612 Veronika rotation time find out Pag.18...

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