RigTonightHow to find deep-sky targets that fit your camera's field of view
The Targets tab is the whole catalog: 520 galaxies, nebulae and star clusters, including all 110 Messier objects. Tonight shows you the best few for tonight. Targets is where you browse, plan ahead and check framing.
Search and filter
Type in the search box: a name ("Heart"), a catalogue number ("M31", "NGC 7000") or a constellation. Then narrow the list:
- Type: galaxies, nebulae, planetary nebulae, star clusters or supernova remnants, or Messier for the Messier list.
- Up tonight only hides anything that doesn't climb above your minimum altitude while it's dark. It needs your location, which you set on the Tonight tab.
- Suits my rig keeps only targets that frame well with your telescope and camera.
Sort the list
- Popular: the famous targets first. A good place to start.
- Best tonight: most clear, dark hours above your minimum altitude tonight.
- Best for my rig: how well each target fills your field of view and suits your filters.
- Brightest first, Messier number or Name when you're looking for something specific.
What "suits my rig" means
RigTonight compares each target's size with your field of view:
- Fills the frame well: the target covers a good share of the sensor without spilling off it.
- Small: it's there, but you'll crop in. A longer focal length shows more detail.
- Tiny: only a few dozen pixels across. Better saved for a longer telescope.
- Bigger than your field: you'd need a mosaic. RigTonight estimates how many panels, allowing for overlap.
It also looks at your filters. A rig with only narrowband filters is marked down for galaxies and star clusters, which shine in ordinary starlight, and a rig with a dual-band filter is marked up for emission nebulae.
Open a target
Click any target to see:
- Framing: a sky preview with your camera's frame drawn to scale on it, so you can see whether the whole object fits and how much space is around it.
- Tonight: when it's photographable, its highest altitude while dark, and how close the moon gets.
- An altitude chart through the night, with your minimum altitude marked.
- For your rig: the Great, Good or Not ideal label with the reasons, and which of your filters to use tonight.
Plan for a different rig
Rankings follow the rig on the Rig tab. Load another rig from My rigs, and the Targets list re-sorts for it. It's a quick way to see what a new telescope or a reducer would open up before you buy it.
Next: saving and sharing rigs, night mode, and using RigTonight at a dark site.