Astronomical Observatories

Made for the Royal Society Summer Science Exhibition 2021

Introduction

One of the most important tools in an astronomer's arsenal are astronomical observatories or telescopes. Observatories typically serve the purpose of collecting more light (sensitivity) with greater sharpness (resolution) than possible by eye and creating a record (e.g. image) of that light.

Observatories are broadly defined by the combination of a optics, instrumentation, location, and support structure and equipment. All four can make a sigificant difference to how well an observatory performs.

Optics: diffraction

Some text.

Use the sliders to control both the telescope resolution


Actual view
Telescope Optics

Telescope Resolution

The Atmosphere: astronomical seeing

Ground-based telescopes also suffer the effects of the Earth's atmosphere. Most of the ultraviolet and infrared light is blocked by our atmosphere, making astronomy at these wavelength impossible from the Earth's surface. And while visible light can travel through our atmosphere, the effect of the atmosphere is to distort and spread-out the light, making it difficult to see detail and observe faint objects.

Use the button to turn on and off the extreme effect of the Earth's atmosphere.


Actual view
Telescope Optics

Atmosphere

Resolution: telescopes and detectors

In order to record an image a telescope needs to use an instrument, typically an imaging camera or spectrograph. Visible light cameras capture light across a grid of pixels. Smaller pixels provide higher-resolution images but increase the noise in each individual pixels as the same amount of light is spread across multiple pixels. Smaller pixels also produce bigger files.

Use the sliders to control both the telescope resolution and the size of the pixels.


Actual view
Detector

Pixel Scale

Sensitivity

Because astronomers are often observing very faint objects electronic noise often becomes a major issue. Such noise is reduced by collecting more light, either by using a larger telescope or collecting light for a longer period of time, also know as integrating. To make its iconic Ultra Deep Field, Hubble observed the same patch of sky for two million seconds.

Use the sliders to add noise to the image.

Actual view
with Noise

noise

Combine these effects

Actual view
Atmosphere
Telescope Resolution
Pixel Scale
Sensitivity
Observed

Credits

This app was designed and coded by Stephen Wilkins and Darren Baskill at the University of Sussex.

Hubble's Legacy was developed and led by Stephen Wilkins at the University of Sussex with assistance from scientists at 10 other UK universities. Hubble's Legacy is also supported by the Science and Technologies Facilities Council.

The full code for the Hubble Legacy project can be downloaded from GitHub here.