Topic 6 Flashcards
What is the appearance of a star in the night sky?
Appears to be a point of light in the sky that scintillates
What are the two types of double star and why are they different?
Binary star & optical binary.
Optical binary stars do not share a common centre to orbit.
What is a binary star?
2 + stars that shave a gravitational bond and orbit around a common centre - they appear to be two closely positioned points of light
What is an optical binary?
Two stars that appear close, and to be binary but are unrelated by gravitational attraction
What is a constellation?
A group of stars that appear to make a pattern in the sky.
We see different throughout the ones year due to our rotation and axial tilt.
What is an asterism?
A pattern of stars that may or may not be linked to a constellation
- the plough is in ursa major
- Deneb is in Cygnus
What is the difference between a constellation and an asterism
They’re both patterns of stars. However, constellations are a group of 88 recognised official patterns. Asterisms are smaller patterns within constellations, nothing official.
The asterism The big dipper / the plough is a part of the constellation called ursa Major
What is a star cluster?
Groups of stars which are gravitationally bound.
What are galaxies?
Gravitationally bound system of stars, stellar remnants, interstellar gas, dust & dark matter
What is a nebulae?
Cloud of gas & dust in outer space, visible in the night sky as either an indistract bright patch or a silhouette against other luminous matter
Appearance of a planet in the night sky
Appear as a point of light in the sky that does not scintillate due to now close they are relative to Earth
What is a comet?
Balls of frozen gases, rock, and dust that orbit the sun.
- point of light clearly noticeable over a short period of time
- vast trails of ice & dust over a large portion of sky
What is a meteor?
Small, rocky, irregular lumps of debris in the solar system
- often originating from the dust trails of comets, forming a group called meteoroid streams and are the source of meteor showers (emerging from the radiant)
- many meteoroids enter the atmosphere and friction causes them to burn up and produce a streak of light (meteor/shooting star)
- streak of light lasts a matter of seconds
What is aurorae?
Bands of coloured light in the sky, curtains of light
- when the solar wind interacts with the atmosphere
What is a supernovae?
Burst of extremely bright light in the sky, very rare
- it is the death of a massive star
How does an artificial satellite appear?
Slow moving, very faint objects orbiting in a polar orbit, viewable on the median
How do aircraft appear?
Multiple bright white & red lights slowly moving over the sky
How does the milky way appear?
Faint grey band in the sky
What is light pollution and how does it affect viewing?
Optical light from human sources.
It reduces contrast in the sky and ruins vision at night.
What things can obstruct viewing at night?
-Air pollution
-Saharan dust
-clouds
-mountains (landscape)
-other celestial bodies
can reduce clarity
What is The celestial sphere?
The imaginery sphere around Earth.
What is right ascension and where is it measured from?
Longitude of a star from the first point of Ares ( imagine a clock)