Time: 12:30 AM
Brief
At our global coordinates, we will end April tomorrow with the three Summer Triangle stars above the horizon as the clock reaches midnight. For this evening, I sped the clock ahead by half an hour, so Altair is a little higher. Vega rises first at 8:36, and Deneb rises second not long after at 9:45. Being about 7º north of Vega, Deneb spends more time above the horizon. Both will be seen high in the sky before and during dawn. Further south and east, Altair does not rise until just before midnight (yesterday into today), and about 30º further south of Vega.
Here is the image of all three stars, with the celestial grid showing to remind us of the declination of each star.
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click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp. |
As the celestial grid shows, Deneb is not far from a circumpolar declination, if viewed from our latitude. If we were not much further north, at least 45º, Deneb would never be seen setting; it would just barely clear the horizon, and spend a few hours very close to it. Further north, as seen from locations from the western Canadian provinces, Great Britain, Siberia, etc, Deneb would be more visible above the horizon at its lowest. The further north a person goes, even Vega eventually becomes circumpolar. Altair would not be that way however, until someone brave enough reached the most northern latitudes nearest to the north pole.
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