
NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2025 Feb 3, 09:38 -0800
Nice! Your photo came out pretty good, Sean. That's also just how it looked here at 2:30 in the middle of the afternoon Saturday. I stepped outside... scanned about a bit to find the Moon (not easy at this phase)... and then looked up 3°... TA-DA! Easy. Didn't even need binoculars for the initial view. It was just "right there"... in plain sight, naked eye.
I am compelled to emphasize here that Venus is easy in daylight each and every day for the next few months except for a few weeks right around inferior conjunction on March 23. All you need is a method for finding it. A robotic telescope can certainly do the job. A phone app isn't good enough. Once you lay eyes on it, it jumps right out at you, and it's hard to believe you didn't see it immediately. This past Saturday when Venus was close to the Moon for observers in North American longitudes, the Moon was the guide. On other dates we can use the Sun or the stars of Orion.
Sun Guide:
Near local noon, find a spot where you can easily hide the Sun behind a convenient foreground feature like a roof peak, a boat mast (if moored!), a utility pole, a distinctive tree limb, or similar object at least ten or twenty meters in front of you. Mark the exact spot on the ground and take note of the time. Return to that spot later in the afternoon, or later in the season, return the next morning. I recommend binoculars for your initial search, but once you have it, you can see it without optical aid. Check this table:
After Sun dates: table gives the delay of Venus after the Sun and the angular offset above (north of) the Sun:
feb1 2h45 18°
feb8 2h35 19°
feb15 2h20 19°
feb22 2h00 19°
mar1 1h35 18°
mar8 1h05 18°
conjunction: mar23 0h 8° [ecliptic latitude offset; min separation]
After conjunction, Venus is a morning object, the "morning star" before sunrise. In this period, you should return to your marked spot (where the Sun was aligned with a foreground object) the next day at a time before you saw the Sun the previous day.
Before Sun dates: table gives time before Sun and angular offset below (south of) the Sun (negative = below/south):
apr5 1h25 -2°
apr12 1h50 -7°
apr19 2h15 -10°
apr26 2h30 -13°
may3 2h40 -15°
may10 2h45 -16°
may17 2h55 -16°
may24 3h00 -15°
Orion Guide:
Find Orion in the evening sky at any time of night convenient to this alignment process. The stars you need are Mintaka in Orion's Belt (northernmost of the three), Betelgeuse above the belt, and later in the season, Procyon, which, of course, is not in Orion, but nearby. Place the required star behind or "perched" on a convenient foreground feature like a roof peak, a boat mast (if moored!), a utility pole, a distinctive tree limb, or similar object at least ten or twenty meters in front of you. Mark the exact spot on the ground and take note of the time. Then check this table:
ALL BEFORE STAR. Time is before the corresponding star. Record your time when your key star is aligned on a Tuesday, and look for Venus the required hours and minutes earlier on Wednesday (*). Angular offset is degrees to the north of the finder star or to the south if negative. Stars are Mintaka, abbreviated Mint, Betelgeuse or Bet, and Procyon or Pro:
feb1 Mint 5h40 1°
feb8 Bet 5h50 -3°
feb15 Bet 5h35 -1°
feb22 Bet 5h30 2°
mar1 Bet 5h25 3°
mar8 Bet 5h25 4°
conjunction: mar23 0h 8° [ecliptic latitude offset; min separation]
apr5 Mint 6h00 4°
apr12 Mint 6h00 3°
apr19 Mint 5h55 1°
apr26 Mint 5h40 1°
may3 Pro 7h35 -4°
may10 Pro 7h20 -3°
may17 Pro 6h55 -1°
may24 Pro 6h30 0°
It works. Try it. By the way for observers in other parts of the world, there will be near Moon days around April 23/24 and May 23. The Moon will also be fairly close to Venus on Mar 1, but not as impressive as this past weekend.
It is interesting to note that Venus is at the same position relative to the stars on Feb 1 and Apr 26. On the celestial sphere, Venus is tracing out a small tight loop, the "Little Fish Loop" over one of the "fish" of Pisces just below the Great Square of Pegasus. Despite passing from 45° after the Sun, as the "evening star", in January to 45° before the Sun, as "morning star" in May, its RA (or SHA) and its Dec are confined to a rather small box for the duration while the Sun passes through...
Frank Reed
* A little trick with the stars. If you have Mintaka, for example, aligned with a tree limb at some time, let's say 8:35pm on a Tuesday, but it's cloudy on Wednesday and Thursday, you don't have to observe Mintaka again. Instead just add four minutes for each elapsed day. If you saw it at 8:35 on Tuesday, then you would have seen it with the same alignment at 8:43 on Thursday. Then on Friday, assumed to be the next clear day, you could observe Venus at 2:43 in the afternoon (if the time offset is exactly 6h00).