Sunday, November 12, 2017

checking visibility part 2

Sent a follow-up to the RASC TC forums regarding Nick's issue of checking the visibility of objects (after my 8 Nov remarks). I had popped into DSO Browser to check something on one of my astrophotos and I spotted the elevation graphs. Similar to SkyTools but online.

elevation charts from DSO Browser

The image shows the data for the Pleiades given the viewing location of Orillia.

The first helps verify the best time to view or shoot in an evening; the second tells you when the item is best viewed in the year.

It lets you adjust the observing time in the Monthly Elevation chart which is cool. SkyTools does too—I've never used the feature before.

I still like the SkyTools YearBar better. A subtle thing is that it includes the moonlighting. From the graph above, we can glean that Pleiades is best in the winter, high in the sky in November, December, and January. For the example date shown, Nov 12, it crosses the meridian around midnight. For 2017, that's OK as there's little moonlight; but in 2018, the sky will be washed out with the stoopid Moon.

Another member referred to a "simple calculation" to locate objects but did not expand.

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