Data: Stellar Quadrant Observations – 1/4/19

Last night was a nearly new moon. The temperature was uncommonly warm for this time of year1 but that didn’t end up disturbing the seeing too much as we had an exceptionally good night for observing. Combined with a rich field of stars in Taurus and Orion passing during the evening and Padraig and I had the most productive evening yet cataloging 59 stars, 16 of which were not in my original list of targets, but due to being able to see down to 5th magnitude, we were able to grab them.

Object Alt Az ST Dec Error2
λ Tau 63.8 180 4:03 12.53 +0.05
ν Tau 57.6 180 4:05 6.32 +0.34
ο1 Eri 44.8 180 4:11 -6.48 +0.35
μ Tau 60.4 180 4:15 9.12 +0.24
ο2 Eri 43.25 180 4:17 -8.03 +0.38
γ Tau 66.8 180 4:21 15.52 -0.10
δ1 Tau 68.85 180 4:26 17.57 +0.04
υ3 Eri 17.5 180 4:25 -33.78 +0.24
κ1 Tau 73.6 180 4:29 22.32 +0.04
υ Tau 73.75 180 4:30 22.48 -0.32
δ3 Tau 68.8 180 4:32 17.52 -0.40
θ1 Tau 67.5 180 4:34 16.22 +0.35
ε Tau 70.2 180 4:34 18.92 -0.25
υ2 Eri 20.45 180 4:36 -30.83 -0.27
ν Eri 48.2 180 4:38 -3.08 +0.27
α Tau 68.3 180 4:39 17.02 +0.52
88 Tau 61.5 180 4:41 10.22 +0.07
l Eri 37.4 180 4:42 -13.88 +0.42
c Tau 63.55 180 4:43 12.27 -0.23
54 Eri 31.35 180 4:45 -19.93 -0.26
τ Tau 73.7 180 4:47 22.42 -0.53
π3 Ori 58.35 180 4:49 7.07 +0.12
π2 Ori 60.3 180 4:49 9.02 +0.12
π4 Ori 57.0 180 4:50 5.72 +0.11
ω Eri 46.3 180 4:50 -4.98 +0.47
α Cam 61.5 0 4:54 67.22 +0.89
ο2 Ori 64.8 180 4:57 13.52 +0.02
π5 Ori 53.75 180 4:57 2.47 0.03
β Cam 68.0 0 4:59 60.72 -0.15
ε Lep 28.0 180 5:00 -23.28 -0.91
β Eri 46.7 180 5:06 -4.58 +0.50
λ Eri 43.0 180 5:07 -8.28 +0.47
μ Lep 35.4 180 5:10 -15.88 +0.32
β Ori 43.4 180 5:11 -7.88 +0.32
τ Ori 44.8 180 5:15 -6.47 -0.36
λ Lep 37.8 180 5:17 -13.48 -0.31
o Ori 50.9 180 5:20 -0.38 +0.01
e Ori 43.8 180 5:22 -7.48 +0.32
γ Ori 57.7 180 5:23 9.72 -0.21
β Lep 30.5 180 5:25 -20.78 -0.03
32 Ori 56.7 180 5:29 5.42 -0.51
δ Ori 50.8 180 5:31 -0.48 -0.20
φ1 Ori 60.8 180 5:35 9.52 +0.03
λ Ori 61.0 180 5:35 9.72 -0.21
ι Ori 45.6 180 5:36 5.68 +0.22
θ Ori 46.1 180 5:36 -5.18 +0.24
c Ori 46.8 180 5:37 -4.48 +0.36
ε Ori 50.0 180 5:38 -1.28 -0.08
φ2 Ori 60.6 180 5:38 9.32 +0.03
ζ Tau 72.4 180 5:39 21.12 -0.01
α Col 17.3 180 5:40 -33.98 +0.09
ζ Ori 49.55 180 5:42 -1.73 +0.17
γ Lep 29.1 180 5:45 -20.78 +0.09
ζ Lep 36.4 180 5:46 -14.88 -0.06
β Col 15.6 180 5:47 -35.68 +0.09
κ Ori 41.8 180 5:48 -9.48 +0.19
δ Lep 30.5 180 5:50 -20.78 +0.09
α Ori 58.8 180 5:52 7.52 +0.12
η Lep 37.3 180 5:54 -13.98 +0.19
Average +0.07
StDev 0.31

As noted above, this was by far our most productive evening. To drive the point home, here’s the plot that the program I’ve written put together3:

All the data we’d collected previously is on the right whereas last night’s data is the dense section on the left, with the large gap in between the few months of observing that were missed due to weather and illnesses.

And on top of the prodigious number of observations we accumulated, the accuracy was exceptionally good as well with the declination averaging just 0.07º off with a standard deviation of 0.31º. This is significantly better than previous observing nights on the data quality standpoint as well.

As previously noted, 16 of these stars were not ones that were on observing list. But Padraig consistently finds stars that are a bit fainter than what I set out to target. Previously, I’ve had my laptop with Stellarium with me so we could try to figure out what it was before making the measurements, but this time, we simply drew directly on the star charts I’d printed, numbering them to determine later. This allowed us to make numerous observations much more rapidly, so as not to worry about identification first, hence how we were able to get multiple observations within a single minute sometimes. This may become the new methodology as it worked extremely well.


  1. High of nearly 50º in January.
  2. Error is vs modern published values.
  3. Keep in mind that this plot is flipped horizontally as compared to how it would be viewed from Earth. It’s also highly distorted, so don’t bother trying to pick out the constellations.