How to Use a Bullseye Finder Chart for Messier Objects

Quick answer

A bullseye finder chart shows the exact position of a Messier object inside a Telrad-style reticle, letting you star-hop accurately without guessing where to point.

Step-by-step guide to using a bullseye finder chart

1. Align your finder with the main telescope: During daylight, aim the telescope at a distant fixed object (a tower or treetop). Adjust the finder's adjustment screws until the crosshairs or bullseye center matches the telescope's eyepiece center. Check alignment on a bright star at night. A misaligned finder is the most common source of frustration. Recheck alignment every session.
2. Choose the right chart volume for your target: The Bullseye Finder Charts of the Messier Objects are split into two volumes: Volume 1 covers M1–M55 and Volume 2 covers M56–M110. Pick the volume that contains your target before heading outside. If you are working through a list, mark the chart pages in advance so you are not fumbling in the dark.
3. Star-hop to the chart's reference star: Use a naked-eye star or a bright star in your finder to get close to the region shown on the chart. The bullseye chart assumes you are already within a few degrees of the target. Do not try to use it as a wide-area atlas. If you cannot find any of the reference stars on the chart, back up to a brighter star and use a planisphere or general atlas to orient yourself.
4. Center the reference star in your finder: Look through the Telrad or reflex finder and move the telescope until the reference star sits at the center of the bullseye reticle. The chart shows the target's offset relative to this star. Make sure the star is exactly centered—not just inside the inner ring. A small centering error magnifies when you shift to the target.
5. Shift the telescope along the chart's offset line: The bullseye chart indicates how far and in which direction to move from the reference star to reach the Messier object. Nudge the telescope in that direction while watching the finder. The object should appear in the finder's outer ring or in the main eyepiece. If the object does not appear, you may have moved too far or in the wrong direction. Return to the reference star and try again with smaller nudges.
6. Confirm the object in the eyepiece: Once you suspect the target is in the field, switch to a low-power eyepiece (25–32 mm) and look for a faint smudge, a small cluster, or a nebulous patch. Compare its position and shape with the chart's depiction. A common mistake is mistaking a background star for a deep-sky object. Use averted vision and look for a non-stellar appearance.

Product facts

• Bullseye Finder Charts of the Messier Objects: Bullseye Star Charts are designed for standard reflex finders such as the Telrad, with each object's location indicated inside a bullseye reticle. You do not need to estimate where the object sits in the finder field—the chart shows it exactly, so you can place the reticle ring over the target.