Data: Stellar Quadrant Observations – Lilies War

This past week was Lilies War, north of Kansas City. With a bit of packing tetris, I was able to fit the full quadrant along with most of my camping gear1 to attend. Despite Lilies being traditionally extremely hot2 and stormy, the weather was quite nice this year with highs in the 70’s most days and lows in the 50’s3. This unseasonably cool weather did bring some storms, but nothing like what we’ve experienced the past few years. Yet between storms I was able to get in a few nights of observing, getting in observations of 59 stellar targets, 26 of which are new to the catalog.

As always, data below the fold.

The first night of observing was on 6/8/2019. This night I was assisted by Ellie and Skooli. The moon was just before first quarter, which was quite bright, but I was still able to see into the range of about magnitude 4.5. Looking over the data, one of the things that stands out is that the time I took the observations was often quite early. Being a bit early isn’t uncommon, but in some cases I believed the target to be on the meridian almost 10 minutes early. The consistency with which this was the case suggests that the quadrant was knocked out of polar alignment. However, since there is little component of the motion with respect to the declination as objects cross the meridian, this had little impact on the altitude.

Object Alt Az ST Dec Error4
α Vir 39.6 180 13:25 -10.97 +0.19
τ Vir 51.9 180 13:59 1.33 -0.21
κ Vir 40.4 180 14:06 -10.17 +0.10
ι Vir 44.5 180 14:11 -6.07 -0.07
α Boo 69.6 180 14:12 19.03 -0.14
η Cen 8.4 180 14:19 -42.17 -0.01
μ Vir 44.9 180 14:36 -5.67 -0.01
ζ Boo 64.1 180 14:39 13.53 -0.19
109 Vir 52.4 180 14:43 1.83 -0.06
α Lib 34.7 180 14:45 -15.87 +0.17
16 Lib 46.0 180 14:52 -4.57 -0.22
σ Lib 25.2 180 14:54 -25.37 -0.09
110 Vir 52.8 180 15:00 2.23 +0.13
β UMi 55.2 0 15:04 74.23 +0.07
φ Lup 14.4 180 15:08 -36.17 +0.09
β Lib 41.2 180 15:13 -9.37 +0.01
γ Lib 35.7 180 15:28 -14.87 -0.08
υ Lib 22.4 180 15:29 -28.17 -0.03
τ Lib 20.7 180 15:29 -29.67 +0.11
δ Ser 61.0 180 15:31 10.43 -0.11
α Ser 57.0 180 15:42 6.43 +0.00
μ Ser 47.3 180 15:44 -3.27 +0.16
ε Ser 55.7 180 15:47 5.13 +0.65
β Ser 66.8 180 15:48 16.23 +0.81
π Sco 24.0 180 15:50 -26.57 -0.46
δ Sco 27.8 180 15:54 -22.77 -0.15
β Sco 30.7 180 15:54 -19.87 -0.06
ξ Sco 39.3 180 16:1 -11.27 +0.10
ω Sco 30.0 180 16:02 -20.57 +0.10
ζ UMi 51.7 0 16:06 77.73 -0.06
δ Oph 46.9 180 16:08 -3.67 +0.02
ε Oph 46.8 180 16:14 -3.77 +0.92
σ Sco 25.1 180 16:15 -25.47 +0.12
α Sco 24.0 180 16:21 -26.57 -0.14
τ Sco 22.4 180 16:32 -28.17 +0.05
ζ Oph 40.0 180 16:32 -10.57 -0.00
ε Sco 16.1 180 16:42 -34.47 -0.17
μ Sco 12.5 180 16:42 -38.07 -0.02
η Oph 35.0 180 17:05 -15.57 +0.15
Jupiter 28.2 180 17:08 -22.37 +0.06
Average +0.04
StDev 0.24

The second night I was able to observe was 6/10. The moon phase was a bit more progressed, but there was a lot of haze and seeing 4th magnitude stars was not going to happen. This night, I was assisted by Cathus and Ellie again for the Jupiter observations. The Jupiter observations were especially important as on this night, Jupiter was at opposition, and as I’ve noted before, observations at opposition are necessary for determining orbits using Kepler’s methods.

Before processing these 6/10 observations, I was quite worried about the data from this night and the previous one. A storm came through and I took the quadrant down to store in my car, and as I did, I noticed the central axle was turned again. This was the same problem I’d had earlier this year that resulted in tossing an entire night worth of data; If the axle is rotated the plumb doesn’t hang straight to read from. However, the quadrant arm wasn’t sticking, so I had to hope it hadn’t become an issue until I took it down. Fortunately, after looking at the data, it seems to be the case as the error is within expected values.

Object Alt Az ST Dec Error5
ι Vir 44.4 180 14:16 -6.17 -0.17
α Boo 69.9 180 14:19 19.33 +0.16
μ Vir 44.9 180 14:43 -5.67 -0.01
β UMi 55.3 0 14:47 74.13 -0.03
α Lib 34.3 180 14:49 -16.27 -0.27
β Lib 41.1 180 15:17 -9.47 -0.09
δ Ser 60.9 180 15:32 10.33 -0.21
α Ser 57.0 180 15:42 6.43 +0.00
μ Ser 47.0 180 15:47 -3.57 -0.14
ε Ser 54.95 180 15:49 4.37 -0.11
ρ Sco 21.9 180 15:53 -28.67 +0.54
π Sco 24.35 180 15:54 -26.22 -0.11
δ Sco 28.05 180 16:00 -22.52 +0.10
β Sco 30.9 180 16:04 -19.67 +0.14
α Sco 24.35 180 16:32 -26.22 +0.21
ζ Oph 39.85 180 16:34 -10.72 -0.15
Jupiter 28.55 180 17:09 -22.02 +0.39
Average +0.01
StDev 0.21

My last night of observing was 6/12. At this point the moon was creeping up on full and all assistants seemed to have other things to do that night. I took a few observations by myself, but ended up turning in early.

Object Alt Az ST Dec Error6
α Lib 35.45 180 14:51 -15.12 +0.88
β UMi 55.6 0 15:00 73.82 -0.34
σ Lib 25.3 180 15:06 -25.27 +0.01
β Lib 41.0 290 15:16 -9.57 -0.19
Average +0.09
StDev 0.47

With the addition of the new observations, here’s how the star chart looks now.

Many of the observations are starting to have multiple observations and a bit of casual inspection indicates that these averages are looking to go a good job of coming closer to a true value than any single observation, which is what we should expect.

Looking forward, I probably won’t be posting much on the Almagest because Kingdom A&S is coming up next month. It will be on the 1 year anniversary of first light of the quadrant, so I think it fitting that I do a retrospective of the year’s observations, looking at things far more comprehensively that I have in these posts.

  1. The only thing I didn’t take was my camp kitchen which was no big loss. The stove hasn’t been working well and I almost never tend to use it as cleaning up on site is challenging.
  2. The past several years, highs have been over 100º F with heat indexes in the hundred teens.
  3. With one night getting into the 40’s!
  4. Error is vs modern published values and only for Dec.
  5. Error is vs modern published values and only for Dec.
  6. Error is vs modern published values and only for Dec.