Are you curious about stars and constellations in Blue Prince? These resources and boons are a must if you want to succeed in each run. Our guide discusses various facets, including those related to the Observatory, the Planetarium, and even a little tidbit about the Spiral of Stars. In any case, please be reminded that this article contains minor spoilers.The stars and constellations in Blue Prince - Observatory and Planetarium guideGenerally speaking, stars are a type of resource that you earn over the course of your playthrough. Different constellations, meanwhile, take effect depending on the number of stars that you have whenever you interact with the large telescope in the Observatory.We've opted to organize this guide as follows: We talk about how you can amass stars quickly, and the constellations that you can unlock as you play. We then briefly discuss the Spiral of Stars, a late-game mystery, as well as the bonuses from the Planetarium. How to earn stars quicklyThere are several ways to get stars in the game. Each visit to the Observatory adds +1 star, as does ending the day in the Planetarium, which nets you +2 stars. Certain items even grant a bonus, such as the Morning Star from the Armory.However, if you really want to get a lot of stars in Blue Prince, you need to make use of experiments in the Laboratory. This process involves collecting all Microchips so you can place them in the Sundial. This lets you download a data packet that contains new Laboratory experiment causes/triggers and effects. Naturally, you want to pick the effect that grants +1 star.As for the causes/triggers, there are two options that are viable in many situations:"Every time dig up trash" - This is good if you have a Shovel, and even better if you drafted the Root Cellar as an outer room."Every time you unlock or bypass security doors" - This is great if you have a Keycard or if you've disabled the metal doors via the Utility Closet. You may also change the Security setting to "high" to increase the number of metal doors in the manor.Lastly, there's a third option that's quite amazing that it's almost like an exploit in and of itself. For this one, you need to get the Nursery: Nurse's Station upgrade via an Upgrade Disk. If you enter the room when you have 10 steps or fewer steps, the Nurse's Station sets your number of steps back to 20.Next, you need to combine this with the "whenever you open your map, lose 10 steps" cause/trigger. Basically, you just keep opening your map and reentering the Nurse's Station to regain your steps. If you play it right, you can amass a ridiculous number of stars indefinitely. How to activate constellationsThe information about constellations in Blue Prince comes from a Library book called The Fixed Stars. Likewise, there's a document called the Star Schedule that's found in the Planetarium. Essentially, these documents tell you about the effects of each constellation, as well as the number of stars that are required to activate them.Going back to what we said earlier: You activate constellation/s depending on your current number of stars when you interact with the large telescope in the Observatory. If you have a lot of stars, then it's possible to activate two or more constellations as part of a combo.North Star: +1 gold; activates at 1 star onward.The Twins: Adds two trunks at the Entrance Hall; activates at 2, 6, and 25 stars onward.The Slice: +3 steps; activates at 3, 10, 14, 18, 21, 25 stars onward.Diamondus Minor: +1 gem; activates at 4, 6, 9, 14, 24, and 29 stars onward.The Southern Cross: Rooms with four doors are more common today; activates at 5, 9, 13, 16, 25 stars onward.Farmer's Apple: Apples restore more steps today; activates at 7, 10, 14, 21, and 25 stars onward.Clavis the Key: +1 key; activates at 8, 13, 17, 22, and 25 stars onward.Diamondus Major: +5 gems; activates at 11, 16, 19, 21, and 29 stars onward.Draxus the Dead: Dead end rooms are more common today; activates at 12 and 22 stars onward.The Sail: Everything is 50% off today; activates at 15, 18, and 23 stars onward.Florealis Bloom of the Sky: Green rooms are more likely to contain special flowers (i.e. those with gems) today; activates at 20 and 24 stars onward.Note 1: At 40 stars, it's possible for seven different constellations to get activated as well.Note 2: Some constellations are required for certain puzzles or tasks. These include the Drafting Strategy Sweepstakes (Draxus the Dead) and the Castle Cipher (Southern Cross).Note 3: If you have the Telescope, you can also use it on the Observatory. This nets you double the effect/results from all current constellations. The Inkwell constellation: It's reroll time!Once you reach 50 stars, you activate the Inkwell constellation in Blue Prince. This is actually one of the more special boons since it grants you a redraw/reroll mechanic: You can spend stars to redraw rooms instead of Ivory Dice.Here's the kicker: You have to reach 50 or more stars again if you want to make use of this mechanic. As such, we actually recommend gathering enough stars until you're well past this amount--i.e. 75 to 99 stars. This way, you can still make use of a few rerolls every now and then during your runs. The Spiral of Stars constellation: The great mysteryAt 100 stars, you unlock the Blue Prince Spiral of Stars constellation. This is one of the biggest mysteries in the game.Upon checking the large telescope in the Observatory at 100 stars, the Spiral of Stars will begin with a short phrase ending with "then."At every subsequent visit thereafter, you add a new word. These additional words/phrases also have effects, including bonus resources or losing steps.The more words are added, the more debilitating the effects become. This culminates once you've completed the whole statement, which warns you that your day will end if you attempt to add another word.The reason why this facet remains a mystery is because the spiral shape is part of several late-game hints. As of the time of this writing, no one has figured out what the Spiral of Stars actually means or if it's part of an overarching puzzle. The Planetarium: More boons if you have a TelescopeLast but not least, let's talk about the Planetarium in Blue Prince. It's not actually available by default as it's a Found Floorplan. To unlock it, you must rotate the Observatory telescope until it's leveled at the upper section of the room (i.e. the one with the wheel). This allows you to open a compartment that contains the Floorplan.While the Planetarium might be a rare drafting option, we encourage you to visit it if you have a Telescope item. That's because the Telescope lets you view the display of the planets on the ceiling.Each time you do this, a bonus resource or item will be added to the Planetarium itself. These include an apple, a locked trunk/chest, an Ivory Dice, a dirt pile, and a Prism Key. These rewards make the Planetarium more enticing to draft in future runs.That does it for our Blue Prince constellations and stars guide. Now that you're ready to collect a bunch of these celestial resources, you might want to boost your gold allowance as well.A surreal adventure filled with wonders and mysteries awaits you in Blue Prince. If ever you feel stuck or lost at any point in time in your playthrough, don't forget to check our Blue Prince guides hub.