A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2020 Apr 4, 15:38 -0700
Sunny skies today above Conanicut Island so I took a minute to look at Venus again at 5:00pm local time in full daylight. Took a quick peek with binoculars to find it. Moved it to a tree limb, and then it was easy naked eye. Once you see, it's remarkably bright. Then when you lose it again, youll swear the planet has dropped through a wormhole.
Another trick to find the right spot...
Go out after sunset tonight and find Pollux. You know Pollux? Next to Castor? But which one is which? Fortunately the stars are in alphabetical order, so Castor is closer to Capella and Pollux is closer to Procyon. Tomorrow Venus is 3h 50m ahead of Pollux (diff in RA or diff in SHA divided by 15), and the Declination of Venus is about 3.5° lower, which is close enough. So go outside tonight at 8:50pm your local time. Bring a rock. Find Pollux and walk to a spot where the star is sitting close to a convenient foreground object like a roof peak, the top of a utility pole, or a tree limb. Drop your rock. Then tomorrow go outside at 5:00pm which is, of course, 3h 50m earlier than when you were outside the previous night. Find your rock. Stand there, and look above that foreground feature. If necessary, start with binoculars. It's easy!
A couple of you asked if there was some easily identifiable time when Venus is visible in daylight. It's called "maximum brilliancy". It's a trade-off between the planet's angular size, which increases as it gets nearer to us, and its illuminated fraction, which decreases as it gets closer. From the end of last month through late May, Venus is near enough to maximum brilliancy that you can see it in daylight. And a reminder: you can absolutely use it for sextant sights under these conditions, but you should think ahead about where it will be in the sky in terms of azimuth relative to the Sun (no point if their azimuths are too close).