Thursday, April 18, 2024

Light pollution and the future of amateur astronomy

Photo of the U.S. Capitol dome at night with a bright, unshielded lightpost in the foreground.
Photo by VillageHero (CC)







A thread on the Cloudy Nights forum got me thinking about light pollution and the future of amateur astronomy, especially the visual astronomy that I love so much. I can only say for certain that amateur astronomy, for those whom circumstances allow, will still be an enjoyable hobby in the future in some form or another.

Based on trends I'm seeing now from my limited point of view, cheap Electronically Assisted Astronomy (EAA), or some semblance of it, will likely be the mainstream portal for new amateur astronomers or casual hobbyists until the next big thing comes along. We're almost there already. EAA is the use of a camera in lieu of an eyepiece at the telescope to capture and view images in near real time. It has recently become more affordable with the introduction of the Seestar S50 Smart Telescope, which is often paired with a tablet on a tripod for viewing its images. While still hindered by light pollution, these telescopes can cut through much of it, making for satisfying imaging even in light polluted areas.

People want to create something to share on social media, not just look at stuff. Who creates astro images and doesn't share them online? Here I am sharing material on visual observing because I can't share the actual views themselves, other than describing them in words or sketches. Social validation is huge in our society, probably always has been, and I don't see that changing.

I think most astro-imaging will be done from the comfort of home using data obtained in the backyard, from remote telescopes, and from data shared online (like Hubble data). Why drive way out, freeze in the cold, set up equipment, etc. when it will no longer be necessary? 

Will light pollution still be an issue for amateur astronomers? I think it will likely only be a pressing issue for a shrinking group of visual astronomers. Imagers, who used to be the biggest proponents of keeping the sky and observing field dark, now can obtain and process fantastic images from horribly light polluted locations, like this one from someone's backyard in Washington, DC. They can reject frames ruined by light, satellites, planes, clouds, etc. Sure, dark skies are better, but are no longer essential to create great deep-sky images. Visual observers have no such recourse.

At our public and club-only star parties, imagers are now the ones with bright unshielded screens, along with those with EAA setups, because dark adaptation no longer matters to them. At the latest public event, a young girl asked me, "Why do you ban white lights and pass out red filter material for our phones when you all have your bright white screens on?" I couldn't answer her.

In the foreseeable future, I think a few visual observers will be the only amateur astronomers with the self-interest to fight light pollution, and it may be mainly wildlife enthusiasts that take up the torch (see what I did there). I think most visual observers will just drive (or move) somewhere darker, or observe the bright planets, the Moon, the Sun, and double stars at or closer to home. That's what I do now.

Tuesday, April 2, 2024

Corvus in 3D

3D Constellation post index and instructions


CORVUS, The Crow


2D image of the main stars of constellation Corvus.




The pattern we see.






The 3D version. Click for a larger image (for phones and small screens).

PARALLEL VIEW:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Corvus.













With labels:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Corvus with labels.













CROSS VIEW:

Cross view stereoscopic 3D image pair of the main stars of the constellation Corvus.




With labels:

Cross view stereoscopic 3D image pair of the main stars of the constellation Corvus with labels.



Data:

Object                Magnitude     Dist. (light yrs.)

ε                               3.0          318
Gienah (γ)                2.6          154
Kraz (β)                    2.7          146
δ                               3.0           87
η                               4.3           60
α                          4.0           49

Hydra in 3D

3D Constellation post index and instructions


HYDRA, The Water Snake


2D image of the main stars of constellation Hydra.





The pattern we see.









The 3D version. Click for a larger image (for phones and small screens).

PARALLEL VIEW:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Hydra.













With labels:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Hydra with labels.














CROSS VIEW:

Cross view stereoscopic 3D image pair of the main stars of the constellation Hydra.













With labels:

Cross view stereoscopic 3D image pair of the main stars of the constellation Hydra with labels.














Data:

Object        Magnitude    Dist. (light years)
η                         4.3           590
σ                         4.4           370
ρ                         4.3           350
58 (E)                 4.4           330
β                         4.3           310
υ                         4.1           264
ι                          3.9           263
μ                         3.8           234
Alphard (α)         2.0           180
ζ                         3.1           167
δ                         4.1           160
ν                         3.1           144
γ                         3.0           134
ξ                         3.5           130
ε                         3.4           129
λ                         3.6           113
θ                         3.9           113
π                        3.5           101

Lacerta in 3D

3D Constellation post index and instructions


LACERTA, The Lizard


2D image of the main stars of constellation Lacerta.





The pattern we see.






The 3D version. Click for a larger image (for phones and small screens).

PARALLEL VIEW:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Lacerta.













With labels:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Lacerta with labels.












CROSS VIEW:

Cross view stereoscopic 3D image pair of the main stars of the constellation Lacerta.












With labels:

Cross view stereoscopic 3D image pair of the main stars of the constellation Lacerta with labels.













Data:

Object                Magnitude     Dist. (light yrs.)

4                                 4.6         2,200
6                                 4.5         1.700
5                                 4.3         1,600
1                                 4.1            620
2                                 4.6            550
HR 8485                     4.5            480
11                               4.5            330
β                                 4.4            170
α                                 3.8            103

Saturday, March 30, 2024

Who says blind people can't observe, too?

My goal is to share my enthusiasm for amateur astronomy observation with as many people as I can. I was thinking that the audio Space Walk Among the Stars guides would be great for blind and partially blind people, except it's completely visual based. So I thought, why not at least try to translate the visual aspect into the sense of touch and make a virtual Space Walk for someone who has never seen the night sky? So I did. Hopefully it conveys some of the pleasure and wonder of observing the night sky.

Virtual Space Walk for the Blind - Winter

Tuesday, March 26, 2024

Eyepiece cheat codes: Determining directions in the telescope

Eyepiece cheat codes logo
In the Space Walk Among the Stars audio guides, I frequently refer to compass directions or position angle. Sometimes I say "right" or "left" from a path we're following in the scope, but that really only applies to Newtonian reflectors, and for that I apologize.

Directions in the telescope can be confusing for beginners and even long time observers. It all depends on how many mirrors your telescope has. Generally, an odd number, and your telescope will mirror-reverse the view. An even number and your telescope will rotate the view 180 degrees.

A Newtonian reflector has two mirrors, the primary at the bottom of the tube and the secondary, the smaller one which directs the light to the eyepiece. In this case, an even number, therefore the view is rotated 180 degrees. (The view is rotated additionally because your focuser is usually located off to the side and your eye is positioned differently throughout the sky, so don’t assume south is always “up.”)

Most people with refractors and Cassegrain telescopes use a 90-degree mirror star diagonal before the eyepiece to give a more comfortable viewing position. That counts as one mirror in a refractor and three in a Cassegrain (which has a primary and secondary mirror plus the diagonal). An odd number, therefore these telescopes will keep the image correct side up, but mirror-reversed. (How your diagonal is rotated will affect what direction is actually "up" in your view.)

If you use an “erect image prism diagonal,” such as an Amici prism or pentaprism, in your refractor or Cassegrain, then you get a “correct image” that is neither rotated nor mirror-reversed (but there may be disadvantages that I won’t get into here).

One thing that stays the same regardless of your telescope type is that without any tracking motor engaged, the stars will always drift to the west (or, if you like, enter the field of view from the east). That’s because the Earth is rotating toward the east, and your telescope is fixed to the Earth. So you can always start with an easy reference point by noting the direction toward which the stars are drifting- that’s west. From there, you apply the correct diagram below and you are good to go!

If you’re interested in more information on how your equipment affects image orientation, see this article from the British Astronomical Association.

Choose the diagram that applies to your telescope

In all telescopes, stars and other objects will always drift to the WEST if the scope does not have a tracking motor operating. Know your telescope and directions in the eyepiece. 

The diagrams below show an example of how position angle (PA) is used to indicate the direction from a primary star to its secondary companion (PA 225 in this example) in reflectors and refractors/Cassegrains (with diagonal). You can also give any directions in the sky using PA or compass direction (270 or west, for example), as in many of these Space Walks. This view would be facing south.

This is for a NEWTONIAN REFLECTOR, such as a Dobsonian, and also for a straight-through finderscope. These show the image rotated 180 degrees from what you would see just looking up or in binoculars. North is COUNTER-CLOCKWISE from West:

 

Diagram for determining directions in a Newtonian reflector.

Tip: In Sky Safari Pro, tap the field of view measurement in the upper right and select "Flip: Both" so the chart will match your view in the eyepiece. Note that it might still be rotated somewhat because of your eye's orientation to the eyepiece.







REFRACTORS and CASSEGRAIN telescopes, typically used WITH A MIRROR DIAGONAL, will show the image correct side up but mirror reversed from what you would see just looking up or in binoculars. North is CLOCKWISE from West:

Diagram for determining directions in a refractor or Cassegrain with diagonal.

Tip: In Sky Safari Pro, tap the field of view measurement in the upper right and select "Flip: Horz" so the chart will match your view in the eyepiece.

Sunday, March 24, 2024

Added a new Space Walk Among the Stars - Binocular Edition

 

Photo of Nikon 10x50 binoculars.
More fun with binoculars! I just added a new Space Walk Among the Stars - Binocular Edition, audio guided tour. This one is for the Winter sky, like the first one, but it uses the brightest star in the sky, Sirius, as a jumping off point to find some really nice star clusters including M41, M93, Collinder 140, M46, M47, M50, NGC 2423, and NGC 2360. 

Give it a try while these are still placed well in the evening once it gets dark, around 9 p.m. EDT. The Moon should be out of the way at that time from about March 28 through April 9, 2024.




Monday, March 4, 2024

Lyra in 3D

3D Constellation post index and instructions


LYRA, The Lyre

2D image of the main stars of constellation Lyra.




The pattern we see.






The 3D version. Click for a larger image (for phones and small screens).

PARALLEL VIEW:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Lyra.








With labels:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Lyra with labels.













CROSS VIEW:

Cross view stereoscopic 3D image pair of the main stars of the constellation Lyra.













With labels:

Cross view stereoscopic 3D image pair of the main stars of the constellation Lyra with labels.













Data:

Object                Magnitude     Dist. (light yrs.)

β                               3.5                960
δ²                              4.3                740
γ                               3.3                620
ε                               4.7                162
ζ                               4.3                156
Vega (α)                   0.0                  25

Tuesday, February 27, 2024

Cygnus in 3D

 3D Constellation post index and instructions


CYGNUS, The Swan

2D image of the constellation Cygnus




The pattern we see.






The 3D version. Click for a larger image (for phones and small screens).

PARALLEL VIEW:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Cygnus.








With labels:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Cygnus with labels.








CROSS VIEW:

Cross view stereoscopic 3D image pair of the main stars of the constellation Cygnus.








With labels:

Cross view stereoscopic 3D image pair of the main stars of the constellation Cygnus with labels.








Data:

Object                Magnitude     Dist. (light yrs.)
Sadr (γ)                      2.2          1800
Deneb (α)                   1.3          1400
Albireo (β)                   3.1           430
δ                                  2.9           165
ζ                                  3.2           143
η                                  3.9           135
κ                                  3.8           124
ι²                                  3.8           121
Gienah (ε)                   2.5             73

Sunday, February 25, 2024

Sagitta in 3D

3D Constellation post index and instructions


SAGITTA, The Arrow

2D image of the main stars of constellation Sagitta.




The pattern we see.






The 3D version. Click for a larger image (for phones and small screens).

PARALLEL VIEW:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Sagitta.








With labels:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Sagitta with labels.








CROSS VIEW:

Cross view stereoscopic 3D image pair of the main stars of the constellation Sagitta.








With labels:

Cross view stereoscopic 3D image pair of the main stars of the constellation Sagitta with labels.









Data:

Object                Magnitude     Dist. (light yrs.)

δ                              3.8                590
β                              4.4                440
α                              4.4                430
γ                              3.5                258

Cepheus in 3D

3D Constellation post index and instructions


CEPHEUS, The King

2D image of the main stars of constellation Cepheus.




The pattern we see.






The 3D version. Click for a larger image (for phones and small screens).

PARALLEL VIEW:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Cepheus.









With labels:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Cepheus with labels.








CROSS VIEW:

Cross view stereoscopic 3D image pair of the main stars of the constellation Cepheus.








With labels:

Cross view stereoscopic 3D image pair of the main stars of the constellation Cepheus with labels.









Data:

Object                Magnitude     Dist. (light yrs.)

μ                                4.0            2,400
δ                                4.1               870
ζ                                3.3               840
β                                3.2               690
θ                                4.2               136
ι                                 3.5               115
ε                                4.2                 85
Alderamin (α)            2.5                49
η                               3.4                 46
γ                               3.2                 46

Saturday, February 24, 2024

Cassiopeia in 3D

3D Constellation post index and instructions


CASSIOPEIA, The Queen

2D image of the main stars of constellation Cassiopeia.






The pattern we see.










The 3D version. Click for a larger image (for phones and small screens).

PARALLEL VIEW:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Cassiopeia.














With labels:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Cassiopeia with labels.













CROSS VIEW:

Cross view stereoscopic 3D image pair of the main stars of the constellation Cassiopeia.














With labels:

Cross view stereoscopic 3D image pair of the main stars of the constellation Cassiopeia with labels.











Data:

Object                Magnitude     Dist. (light yrs.)

κ                                4.2             4,700    
ζ                                3.7                590
Navi (γ)                     2.2                 550
Segin (ε)                   3.3                 410
Schedar (α)               2.3                 228
Ruchbah (δ)              2.7                   99
Caph (β)                    2.3                   55
η                                3.5                   19

Friday, February 23, 2024

Perseus in 3D

 3D Constellation post index and instructions


PERSEUS, The Hero

2D image of the main stars of constellation Perseus.




The pattern we see.






The 3D version. Click for a larger image (for phones and small screens).

PARALLEL VIEW:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Perseus.







With labels:

Parallel view stereoscopic 3D image pair of the main stars of the constellation Perseus with labels.







CROSS VIEW:

Cross view stereoscopic 3D image pair of the main stars of the constellation Perseus.







With labels:

Cross view stereoscopic 3D image pair of the main stars of the constellation Perseus with labels.








Data:

Object                Magnitude     Dist. (light yrs.)

Double Cluster           5.3         9,600/6,800     
ξ                                  4.1                   1,200
ο                                  3.9                   1,100
η                                  3.8                      880
ζ                                  2.9                      750
ε                                  2.9                      640
ν                                  3.8                      560
δ                                  3.0                      520
Mirfak (α)                     1.8                      510
ρ                                  3.4                      308
τ                                   3.9                      254
γ                                  2.9                       243
κ                                  3.8                       113
Algol (β)                      2.1                        90
ι                                   4.1                        34