Postcard from Hawai’i – Gecko
Author: Andrew
An electrical engineer, amateur astronomer, and diver, living and working on the island of Hawaiʻi.
Postcard from the Universe – Rosette
Rare Brown Dwarf Discovery Provides Benchmark for Future Exoplanet Research
W. M. Keck Observatory press release…
A team of researchers led by Justin R. Crepp, the Freimann Assistant Professor of Physics at the University of Notre Dame, has directly imaged a very rare type of brown dwarf that can serve as a benchmark for studying objects with masses that lie between stars and planets. Their paper on the discovery was published recently in Astrophysical Journal.
HD 19467 B, a T-dwarf, is a very faint companion to a nearby Sun-like star, more than 100,000 times as dim as its host. Its distance is known precisely, and the discovery also enables researchers to place strong constraints on important factors such as its mass, orbit, age, and chemical composition without reference to the spectrum of light received from its surface.
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UCSC Scientists Capture First Cosmic Web Filaments at Keck Observatory
W. M. Keck Observatory press release…
Astronomers have discovered a distant quasar illuminating a vast nebula of diffuse gas, revealing for the first time part of the network of filaments thought to connect galaxies in a cosmic web. Researchers at the University of California, Santa Cruz, led the study, published January 19 in the journal, Nature.
“This is a very exceptional object: it’s huge, at least twice as large as any nebula detected before, and it extends well beyond the galactic environment of the quasar,” said Sebastiano Cantalupo, first author of the paper and a postdoctoral fellow at UC Santa Cruz.
The standard cosmological model of structure formation in the universe predicts that galaxies are embedded in a cosmic web of matter, most of which (about 84 percent) is invisible dark matter. This web is seen in the results from computer simulations of the evolution of structure in the universe, which show the distribution of dark matter on large scales, including the dark matter halos in which galaxies form and the cosmic web of filaments that connect them. Gravity causes ordinary matter to follow the distribution of dark matter, so filaments of diffuse, ionized gas are expected to trace a pattern similar to that seen in dark matter simulations.
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Postcard from Hawai’i – Another Rainbow
The Hotech CT Laser Collimator
With Jupiter still near opposition and Mars opposition approaching I would like to do a little high resolution planetary imaging. For planetary I use our Nexstar 11″ telescope, with 2800mm of focal length is has the high magnification needed.
The Nexstar has not been giving me the results I know it is capable of. I shot Venus just before inferior conjunction and noted that there was probably some issues in collimation that were not addressed in the quick star collimation I had performed.
Thus I borrowed a Hotech CT Laser Collimatior from a friend. The collimator is an interesting piece of kit, enabling the user to check more than simple the tip-tilt of the secondary.
Postcard from Hawai’i – Another Rainbow
Postcard from Hawai’i – Tools of the Trade
Postcard from the Summit – Laser
Capturing the Mountian Shadow
A high quality pan-tilt-zoom camera on the roof of the observatory at an altitude of 13,630ft? Just too much fun. I have found myself logging into the camera at sunset to enjoy the view, or keeping the video in the corner of my screen through a Hawaiian blizzard. I have even forwarded images to a local television station when they requested views of a white Christmas in Hawaiʻi. Yes, they used them for the evening news!
To make the best of this wonderful toy I need some tools. To that end several Python programs have been written, including a camera scheduler. This program takes a text file with a schedule and captures images at the programmed time and date. All of this was easy to implement in Python, all of the necessary ‘net protocol support is available in the libraries.
The schedule file can contain any number of separate schedules for multiple sequences. At the specified time the program insures the camera is set properly, moves the camera to the correct position and captures the image. Each sequence is saved to a unique directory and given a sequential name suitable for compiling time lapse video. Add a simple GUI to allow images and status to be monitored and the program becomes a very useful tool.
There are now multiple sequences running… Photos of the summit ridge at each sunset, the shadow of the GPS antenna every day at noon, the Kohala mountain every day mid-morning, the TMT construction site several times a day, and more.