This one came about with some discussion of the new Spelljammer content coming out. I think a wizard that studies the stars is very thematic. Although there is some focus on things like the zodiac and horoscopes, most of this wizard's knowledge surrounds celestial bodies like comets and stars. Let me know what you think 

Astrology

(Dunamancy): If the spells from Explorer’s Guide to Wildemount are being utilized as part of the campaign, an Astrology wizard has access to the dunamancy spell list. 

Star Mapping 

Beginning when you choose this school at 2nd level, you gain proficiency in the Survival skill. While traveling at night (or in another space surrounded by celestial bodies) you have advantage on any Wisdom (Survival) checks made to navigate.

Additionally, you gain proficiency in Cartographer’s Tools. Using these tools, you can chart a Star Map in one of the pages of your spellbook as part of a long rest. Doing so allows you to use your spellbook as a spellcasting focus for your wizard spells. 

 

Celestial Spellcasting

Also at 2nd level, whenever you cast a wizard spell, you can use the influence of heavenly bodies to alter its casting in one of the following ways:

• Traveling Comet: When you cast a spell with a range of 5 feet or greater, you can double the range of the spell. If the spell deals damage, you can change the damage dealt by the spell to radiant. 

• Constellation: The first time you make a ranged spell attack, you can choose to target two creatures within 10 feet of each other instead of one, making a separate attack roll for the new target. Any time you score a critical hit on an attack roll made as part of this casting of the spell, the energy leaps to a different creature of your choice within 10 feet of the original target: Make a ranged spell attack roll against the new target, which could cause the spell to leap again. Each additional attack made as part of this feature has the same effect as the original spell on a hit. 

• Focal Star: When you cast a spell that targets only a single creature or object, you can choose to enhance the target’s gravitational pull. When the target is initially affected by the spell, and as a bonus action on each of your turns while the target remains affected by the spell, you can force each creature within 15 feet of the target to make a Strength saving throw against your spell save DC. On a failed save, a creature is pulled up to 10 feet towards the target ending its movement in an unoccupied space. 

You can use this feature a number of times equal to your proficiency bonus and regain all expended uses when you finish a long rest. 

 

 

Horoscope

Starting at 6th level, you learn the Augury spell, which counts as a wizard spell for you. This spell is always prepared and does not count against the number of spells you can prepare each day. When you cast the spell at night (or in another place surrounded by celestial bodies), you can ignore the material component of the spell. 

Channel the Zodiac

Also at 6th level, you learn the Enhance Ability spell, which counts as a wizard spell for you. This spell is always prepared and does not count against the number of spells you can prepare each day. You can use this feature to cast the spell once at its lowest level, targeting yourself. After you do so, you cannot cast the spell this way again until you finish a long rest. 

 

Improved Celestial Spellcasting

At 10th level, your ability to invoke the power of celestial bodies is enhanced, leading to the following improvements for each option available to you:

• Traveling Comet: After applying this option, the first time you make a damage roll for the spell you add your Wizard level to the total. 

• Constellation: After applying this option, any attack roll(s) made as part of the spell scores a critical hit on a roll of 19-20 on the d20.

• Focal Star: After applying this option, a creature which fails its Strength saving throw takes radiant damage equal to your Intelligence modifier if it is within 5 feet of the target after being pulled.

Additionally, you can now apply more than one of these options when casting a wizard spell, expending a seperate use of this feature for each option chosen. Each option can still only be applied once to the casting of a spell. 

Cosmic Projection 

At 14th level, you are able to call upon the power of heavenly objects wherever you find yourself across the planes. As an action, you can evoke an aura filled with illusionary, celestial bodies in a 20-foot radius. This aura lasts for 1 minute, but ends early if you are incapacitated. While using this feature, you and any friendly creatures within the aura can add 1d8 to any ability check, attack roll, or saving throw which uses its Intelligence modifier.

Additionally, once while this feature is active you can cast a spell of 5th level or lower which you have prepared without expending a spell slot or material components. The spell must either be from the divination school of magic or affected by your Celestial Spellcasting feature to be cast this way. 

Once you have used this feature, you cannot use it again until you finish a long rest.