Astrophotography – Revealing the Universe

In the last blog post available here we covered how astronomers gradually used new discoveries in photographic techniques to not just record what could be seen at the telescope’s eyepiece but to capture even fainter details than humans could perceive.

Like new technologies tend to do, once photography became commonly available advances in materials and techniques quickly arrived.  Major telescopes at professional observatories that were built in most of the 19th century were designed purely for visual observing. It was only late in the 1890s that telescopes were constructed with astrophotography in mind. Notable were the 40” Yerkes refractor – still the largest of its type –  and the 60” reflector on Mt Wilson which was the largest telescope in the from 1908 to 1917.

 

The 60″ Telescope at Mt Wilson, California.

It was from the analysis of photographs taken through the 60 inch telescope that astronomer Harlow Shapely measured the brightness and distribution of variable stars in the Milky Way and globular clusters surrounding it. He suggested the Milky Way was vastly larger than then current estimates. He also showed the Sun and the Solar System were not as thought, in the centre of the Milky Way but  much further away, about two thirds of the way towards the edge of the galaxy.

One of  Harlow Shapely’s images from Mount Wilson Observatory

Astrophotos had changed the where we thought the Earth was located much like Copernicus had moved the Earth from the centre of our Solar System. And there was more to come!

We won’t go into details here about George Ellery Hale, the astronomer behind the Yerkes 40″ and Mt Wilson 60″ telescopes. He was a towering , complex figure. If you’re not familiar with this life, he’s well worth discovering or talk to us at BINTEL – we’ll chew your eye off about this period.  Having been the driving force behind these two observatories, he then went on to establish another two large telescopes, the 100″ Hooker Telescope at Mt Wilson and the 200″ Hale telescope at Mt. Palomar.

Some of the most important astro photos of all time were taken with the 100″ Hooker Telescope

Three years after the “The Great Debate”, a series of lectures in 1920 which intensely discussed the topic of are the “spiral nebula” seen in the night sky part of the Milky Way or galaxies in their right, astronomer Edwin Hubble used the 100″ Hooker telescope to measure the brightness to variable stars to show M31, the Great Andromeda Spiral Nebula was in fact outside the Milky Way and another galaxy. The Milky Way was not the entire Universe. We live on the edge of one of countless galaxies in our Universe.

Negative of Edwin Hubble’s image of M31

Over the space of just a few short years, Earth had been removed from being at the centre of the Milky Way and the Milky Way itself was no longer unique.

But wait, there’s more…

Building on previous work, Hubble and his assistant Milton Humason noticed something curious once they started to measure the distance to galaxies using variable stars. The further away a galaxy is, the faster it’s receding away from us and this in all directions too.

Hubble and Humason at Mt Wilson

Speed away from the Milky Way was measured using “red shift”. The lines on a spectra showing the make up of the galaxy was moved towards the red or longer wavelength of the spectrum caused by the Dopler Effect This is same thing you hear from a car that goes past you. The sound it makes changes tone.

This “Expansion of the Universe” shown on photographic images was confronting on numerous levels. The issue of a seemingly endless Universe that had existed for all time become difficult to accept. What if you ran time backwards? Was there a “Big Bang” when this expansion of the Universe began?

Will gravity overcome the force that pushed galaxies out into space and will it collapse back on itself? Currently not only is the Universe expanding,  but the rate of this expansion is accelerating due the presence of Dark Energy. It’s force that’s yet to be fully explained and discovered using images taken from the Keck and MMT Observatories of exploding stars called Type 1A Supernova.

Whether Dark Energy will always continue to drive the rate of expansion in unknown. Some researches have even suggested it will possibly fade away over time and the Universe will collapse back itself – or matter will continue to fly apart.

Part of the JWST’s mission is to help us learn more about the early formation of the galaxies so we can come closer to discovering the Universe’s ultimate fate. In much the same way those fragile glass plates from Mt Wilson changed who we see ourselves, who knows where the JWST will lead us!

 

Leave a Reply

Your email address will not be published.

Fill out this field
Fill out this field
Please enter a valid email address.

NASA Returns to the Moon

It’s been 50 years since NASA last sent astronauts to the Moon! After decades of delays, NASA is finally returning humans to the Moon in the coming years. The first launch of the mega rocket that will take them there and help establish a permanent presence is scheduled for 29th August 2022 (USA time) and…

BIG Telescopes are on the way. Here’s some of them.

We’ve all be stunned by the images sent back by the James Webb Space Telescope (JWST) – but what’s happening on the ground? First of all, let’s look at why astronomers go through such enormous effort to put telescopes into space. The complexities of designing a telescope to work in space, launching it into orbit…

JWST Image releases: What’s next?

The James Webb Space Telescope – JWST – is now fully operational and has released its first science images this week that grabbed the world’s attention. With the JWST now “Open for business”, the world’s best astronomers are lining up to use this powerful new instrument.  To use the JWST you must go through a…

Astrophotography – Starlight meets the computer

According to the American Astronomical Society, the  charged couple device or CCD   was born on 17 October 1969 at Bell Labs in Murray Hill, New Jersey during a brain storming session between Willard Boyle and George Smith.  While it was originally intended as a solid state storage device, the imaging possibilities quickly became obvious. (Boyle…

Spotting Scopes and Binoculars – what’s the difference?

Most people are familiar with binoculars.  You might have even used a pair at the footy or cricket,  to watch  some of our wonderful native Australian birds and wildlife or even stare up the  night sky. We get many questions about when you should be using a spotting scope compared to binoculars. There’s no simple…

Harmonic Drive Telescope Mounts

What do the ZWO AM5, the iOptron HEM27 telescope mounts and the wheels of the Apollo Lunar Rover have in common? They’re all driven by a Harmonic Drive. There’s been a lot of excitement about the recent announcement of affordable telescope mounts using Harmonic Drives.  These mounts offer some features that make them of great…

📷 Astrophotography – The Early Days

Humans have produced star maps, charts, drawings and other records of the unchanging night sky above us going back to ancient times. However,  even the most talented artists were limited to what could be seen with their eyes. Early pioneers of using the telescope for astronomy quickly discovered they needed to record and share their…

⊚ The Changing Rings of Saturn

Saturn takes 29 years to orbit the Sun. The view we see of it rings changes during this time for the same reason we have seasons. Like the Earth, Saturn is on a tilt.  Image of Saturn’s changing rings by Kevin Parker When you take your telescope out to view Saturn this winter, you might…

⚫️ First Image of Our Super Massive Black Hole

Image of the super massive black hole at the centre of the Milky Way released by a global research team EHT Collaboration 12th May 2022.  Our home galaxy, The Milky Way, has long thought to contain a super massive black hole. This is something observed not just in the Milky Way, but in many other…

How many stars can I see in the night sky?

How many stars can you count? Have you ever been under a completely dark night sky, on a night with no Moon light?  There’s nothing quite like that carpet of stars that stretches from horizon to horizon with the cloudy Milky Way running through the middle. But just how many stars can you see at…

Shopping cart
There are no products in the cart!
Continue shopping
0