 Hey everyone, Nico Carver here. I often start my videos by saying I'm a deep-sky astrophotographer, but I realized there are a lot of terms we use in the hobby of amateur astronomy that really could use a bit of Explanation and a deep-sky object or DSO for short is one of those terms So here's my definition based on how people actually use the term in my experience a deep-sky object is any object out in space outside of our solar system Excluding individual stars and the Milky Way as a whole so let's break this down a bit more And I'll start with the things that are not deep-sky objects The first group are solar system objects and these include the moon the planets asteroids meteors and comets I'll talk about more about comets next week because we're going to be talking about Charles Messier and his famous catalog of not comets The moon and the planets are of course very bright in our night sky the brightest objects in our night sky Because they're lit by our Sun and speaking of the Sun the next category of things we don't call deep-sky objects are Individual stars so even though by definition all stars other than our Sun are outside of our solar system If it's an individual star we don't call that a deep-sky object The last thing we typically don't call a deep-sky object is our own galaxy the Milky Way as a whole now Of course, there are many deep-sky objects within the Milky Way So let's cover now what is included under the term deep-sky object We have star clusters which can be further broken down into open star clusters like the beehive cluster or m44 and globular star clusters like m13 We have my favorite personally nebulae which can be broken down into many categories, but the main three are Emission nebulae like the lagoon reflection nebulae like the Pleiades and dark nebulae like the boogeyman nebula Most star clusters and nebulae that we photograph are inside our Milky Way galaxies again Most star clusters and nebulae are inside the Milky Way Which leads me to the last big type of deep-sky object Which is galaxies and to break that down further galaxies come in many different types Like spiral galaxies, barred galaxies, starburst galaxies, irregular galaxies, and interacting galaxies Okay, so that's it now that you know what a DSO is. Why is this a useful distinction? Well for the amateur astronomer astrophotographer The practical thing you need to know about DSOs is that they are usually dimmer than solar system objects and individual stars There's that we call them faint fuzzies for a reason and this makes them a lot more challenging to observe at the eyepiece visually They're slightly less challenging Photographically because the camera has this unique advantage of being able to take long exposures Which our eyes can't do our eyes are like high frame rate video cameras refreshing all the time But of course the long exposures and a camera add new wrinkles due to the Earth's rotation So in the end DSOs are challenging to both view and to photograph, but they're so beautiful I think that challenge is well worth taking on one last thing and i'm saving it for last because I realize it's a bit pedantic The more agreed upon term is deep sky, but you'll see many people using deep space and deep sky interchangeably But just you know when people say deep space object, I think they're referring to the exact same thing as a deep sky object The only reason I bring this up and I think that it gets a little functionally confusing Is nasa named their array of giant radio antennas that receive messages from our interplanetary spacecraft like the mars rover The deep space network. That's the name for the antennas, but they're referring to a communication system for spacecraft within our solar system So to avoid potential confusion, I'll always use the term deep sky object rather than deep space object Well that wraps it up. This was the first in a new series. I'm calling five minute fridays Hopefully I stayed to that limit and I'm going to try my best Every week to keep it under five minutes next week I'll be talking about charles messier and the messier catalog and why it's still important to know about for amateur astrophotographers Until then this has been nico carver from nebula photos dot com clear skies