Welcome to 2022! In this posting, we’ll examine how the pandemic impacted amateur astronomy this past year and review our most popular social media posts from 2021.
What a way to end the year! We had the 19 November 2021 (almost total) Lunar Eclipse followed two weeks later by the 4 December 2021 Total Solar Eclipse. While the first event was at an odd hour and the second an odd location, Tele Vue scopes did capture both events. This blog is a gallery of your eclipse photos!
November Lunar Eclipse Images
Have you been gearing up and packing for the December 4th total solar eclipse? If not, you are not alone! The path of totality for this eclipse will be limited to distant Antarctica and the surrounding waters. So very few people will have snow boots on the ground there to enjoy the 1′:54″ view of the solar corona that day. The partial eclipse outside the path of totality is no consolation prize. It envelops the ocean south of Australia, South America, and Africa and barely makes landfall at the very tips of South America, Australia, and New Zealand. Much of the southern tip of Africa will see at most a “nibble” taken out of the Sun.
November, from the Latin novem for nine, is the eleventh month of the year. The name comes from a time when the Romans had only ten named months totaling 304 days. The remaining days in the year were during winter and not assigned to a month. Interesting! With that out of the way, in this blog we’ll highlight November planetary events for sky watchers!
Famous as the butt of planetary jokes and puns, the “ice giant” Uranus will be visible all night on November 5th when it rises in “opposition” at sunset (hence it is opposite the Sun from Earth’s viewpoint). It will also be at its largest for the year: a diminutive 3.76″ of arc. It became magnitude 5.7 at the start of September this year and will stay that bright until early January 2022. Due to its distance and close-to-circular orbit, Uranus doesn’t vary that much in brightness over time. It’ll spend the rest of the year in the 5.8 – 5.9 magnitude range before the next opposition approaches. While technically a naked-eye target in dark skies, you’ll need magnification to confirm you’re looking at a planet and not a field star.
Back in March 2019 this blog featured a Tele Vue-NP127is APO refractor image gallery by astrophotographer Jerry Macon. All those images were done with red, green, and blue (RGB) filters or a dedicated color camera. Jerry has since added the Hubble Palette filters (SHO: Sulfur II, Hydrogen-alpha [Hα)] and O III) to his repertoire, and the color camera is no longer used. We feel Jerry’s imaging has evolved to another level of perfection in the past two years. So in this blog, we look at some of his latest work with the NP127is.
Cataloged as Simeis 147 and Sharpless 2-240, the name “Spaghetti Nebula” is its most descriptive moniker. This nebula is huge: it spans 3° (6 full-moon widths). It is the remnant dust and gas of a massive star that ended life in a supernova explosion. In this case, it left behind a pulsar (a radio-emitting, spinning neutron star). Due to discrepancies between the estimated age of the nebula and pulsar, some posit that two supernovae explosions happened in this region some time apart. Whatever the history of the object, we can say Jerry’s Spaghetti Nebula is quite tasty to the eye.
In this installment, we travel to Kitt Peak in the Arizona-Sonoran Desert to “speckle” binary stars and finally learn what the impressive-sounding Bundesdeutsche Arbeitsgemeinschaft für Veränderliche Sterne group does! (If you missed our prior Tele Vue Scientific installments, you can click to read Part 1 and Part 2).
Introduction Often practiced by amateur astronomers doing planetary work, “lucky” imaging was invented by professional astronomers to try to “freeze” distortion of starlight passing through our planet’s turbulent atmosphere. This is done by taking many short exposures of a target, instead of one long one. Amateurs usually align and stack the best quality photos to create an image. Professionals use their data to perform speckle interferometry involving complex math. Speckle interferometry is useful in refining the orbits of close binary stars. The introduction to a 2014 paper, “Kitt Peak Speckle Interferometry of Close Visual Binary Stars,” explains how this works.
The resolutions of conventional visual binary observations were seeing limited until Labeyrie (1970) devised speckle interferometry as a way to circumvent seeing limitations and realize the full diffraction-limited resolution of a telescope. The light from a close binary passing through small cells in the atmosphere produces multiple binary star images which, if observed at high enough magnification with short exposures (typically 10 to 30 milliseconds), will “freeze” out the atmospheric turbulence and thus overcome seeing-limitations. Although the multiple double star images are randomly scattered throughout the image (often superimposed), their separation and position angle remains constant, allowing these two parameters to be extracted via Fourier analysis (autocorrelation).
The paper says that this technique, made practical with the introduction of the CCD camera, resulted in an order of magnitude improvement in binary star data measurement over visual observations. Speckle interferometry then became the preferred technique for characterizing close binary stars.
Back in December 2018, we featured some spectacular wide-field, deep-sky images by Diego Cartes Saavedra in Chile. All the images were taken with his Tele Vue-76 APO refractor and Tele Vue TRF-2008 0.8x Reducer/Flattener. This combination achieves a 380mm focal length at f/5, ideal for imaging large swaths of deep sky. You can still read the original blog at Tele Vue-76: Imaging the Southern Hemisphere. At the end of that post, we wished Diego continued success in his astrophotographic journey. Ever since, we’ve followed his progress through his postings on the AstroBin imaging hosting platform for astrophotographers. We felt it was time to “catch up” with him and post some of his latest captures in this gallery blog.
Prior generations of supernovae explosions spread dust and gas in this complicated region of space. Continued explosions compressed this material and sparked the formation of new massive stars. Stellar winds from these stars intricately sculpted the region into areas of glowing gas, reflection nebulae, and dark clouds of dense matter. The resulting dark, dusty lanes conjure up images of two dragons. Light from open cluster NGC 6193 illuminates the large blue reflection nebula where the dragons face off. The dense, blue object at the lower-right is pk336-00.1 (also NGC 6164 & NGC 6165) ─ an emission nebula formed from the expanding outer layers of a giant, hot, O-type star at the center. Around this compact object is the faded outer ring of reflected blue dust from earlier shedding events. This image was awarded an AstroBin “Top Pick” nomination.
In the last blog, we covered the history of the Newtonian reflector, its inherent aberrations, and how Tele Vue’s Paracorr enlarged the “sweet spot” of fast scopes to cover the entire field. We also compared the Paracorr – Newtonian combination against more “exotic” telescope designs for imaging. If you missed it, you can read Part 1 before continuing.
Which Paracorr to Use?
Over the years there have been two optical versions of the Paracorr. The original Paracorr came in various mechanical designs which developed as we developed new eyepieces. For this BLOG, we’ll focus on the currently available three versions of the Type-2 Paracorr: 2″ Photo/Visual, SIPS, and 3″ Photo models. Performance improvement over the original Paracorr is most noticeable on all Newtonian/Dobsonian telescopes of f/4.5 and faster.