Looking on the internet deeply has found these results:

this is a sun is the most popular phrase on the web.

that is a sun 115,900 results on the web	this is a sun 14,340,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
Sep 25, 2015 ... Carl Ryan 2 months ago. *That is a Sun Fish?. Read more Show less. Reply � 1 2. ? Report spam or abuse. Curtis Kachur 2 weeks ago. the part�... ... looking out the window saying "it's sunny outside, that is a sun". That's a fact, a fundamental thing, which isn't relative.. it's the sun. It's not a cloud, it's the sun. Jun 26, 2014 ... If That Is a Sun Halo, Then What Is a Sun Dog? Similar to sun halos, sun dogs form when ice crystals with diameters larger than 30 micrometers�... Jul 1, 2015 ... Oh please, that is a sun colored like that from fires. They are having fires throughout PA. Do a search that says "Current Fires in PA."...and you�...	It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

that is a sun

115,900 results on the web

this is a sun

14,340,000 results on the web

More popular!

Sep 25, 2015 ... Carl Ryan 2 months ago. *That is a Sun Fish?. Read more Show less. Reply � 1 2. ? Report spam or abuse. Curtis Kachur 2 weeks ago. the part�...
... looking out the window saying "it's sunny outside, that is a sun". That's a fact, a fundamental thing, which isn't relative.. it's the sun. It's not a cloud, it's the sun.
Jun 26, 2014 ... If That Is a Sun Halo, Then What Is a Sun Dog? Similar to sun halos, sun dogs form when ice crystals with diameters larger than 30 micrometers�...
Jul 1, 2015 ... Oh please, that is a sun colored like that from fires. They are having fires throughout PA. Do a search that says "Current Fires in PA."...and you�...

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.