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Over Analyzing A Stellar Spectrum

Astronomers are using new telescopes in their search for smaller black holes.
They are probably over analyzing (or looking for more than is there) a stellar spectrum as part of their search. Their assumptions are probably invalid for the specific wavelengths being analyzed.

They suspect small black holes need a new method to detect them. They call these a new class of black holes.

excerpt ===
Black holes are an important part of how astrophysicists make sense of the universe – so important that scientists have been trying to build a census of all the black holes in the Milky Way galaxy.
But new research shows that their search might have been missing an entire class of black holes that they didn’t know existed.
===

my comment:
Here in EUT, black holes don't exist so they add nothing to making 'sense of the universe.'

Their approach taken in this effort is interesting so this post is worthwhile.

excerpt===
He and other scientists began combing through data from Apache Point Observatory Galactic Evolution Experiment, which collected light spectra from around 100,000 stars across the Milky Way. The spectra, Thompson realized, could show whether a star might be orbiting around another object: Changes in spectra – a shift toward bluer wavelengths, for example, followed by a shift to redder wavelengths – could show that a star was orbiting an unseen companion.

Thompson began combing through the data, looking for stars that showed that change, indicating that they might be orbiting a black hole.
===

Among the instruments:
Tillinghast Reflector Echelle Spectograph (TRES)

excerpt from the University of Arizona description ===

The [TRES] design is a high-throughput fiber-fed echelle. It is cross-dispersed, yielding a passband of 390-910 nm.
===

My comment:

This is an interesting passband.

There is no description explaining this selection.
The following is only my suspicion based on that stated range.

For reference:

UVA 315-400 nm

visible colors 380-750 nm

near infrared 1 um

Here are some wavelengths in this range:

Hydrogen Lyman-alpha  121.6 nm (not in the range; this is H ground state)


hydrogen alpha 656.45337 nm or Ballmer-alpha - red
hydrogen beta 486.13615 nm or Ballmer-beta - aqua
hydrogen gamma 434.0462 nm or Ballmer-gamma - blue
hydrogen delta 410.174 nm or Ballmer-delta - violet
hydrogen epsilon 397.0072 nm or Ballmer-epsilon - UV
hydrogen zeta 688.9049 nm or Ballmer-zeta - UV
hydrogen nu 383.5384 nm or Ballmer-nu - UV


Suggested from the above: they are monitoring all the wavelengths for the respective energy states of hydrogen atoms that are not at ground state. Their passband will capture those specific lines shifted to the blue (to UV) or red (to near infrared). Their narrow passband will not cover extreme shifts.
A shift of Balmer-alpha to UV (390 nm) is z=-0.41, or -1.22E5 km/s
A shift of Balmer-alpha to IR(910 nm) is z=+0.39, or +1.2E5 km/s

However, this approach has the problem noted in my post on October 28 on Stellar Motion.

These are loose atoms above the surface and are not always part of the star's motion. These atoms in motion could even be part of a CME.
The study assumes any shift in these wavelengths are caused only by the star's motion. That assumption cannot be justified.

I have another suspicion about this passband which I cannot verify. I posted about the 1998 supernova study on October 30 titled Supernova Luminosity Curve Stretching in Time.
Figure 10 in that study showed a smoothed curve with many stellar absorption lines from several metals to enable a measurement of motion (by their red shift) of the supernova's remaining star.
That measurement using absorption lines is not valid (as I suggested in that post). Perhaps with that technique used in the pivotal 1998 study, this subsequent study felt justified to do the same when looking at a star assumed to be in motion around an invisible black hole.
These hydrogen atom wavelengths will not reveal the star's motion when above the radiant surface.

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