September 29
The Circumpolar Tip
Sun Position
The Sun is in Libra at about -5ยฐ declination. For Northern Hemisphere observers near 45ยฐN latitude, nights are now about 13 hours long; Southern Hemisphere observers are experiencing symmetric spring conditions.
Sky Highlight
Cassiopeia is now above the pole and visible all night from latitudes north of about 30ยฐN, making it the reliable background constellation for the entire autumn and winter observing season. No major meteor shower peaks today.
Deep Sky Object
NGC 869 / NGC 884, Double Cluster, Perseus. These two open clusters, each about 7,500 light-years away, are well-placed overhead for mid-northern observers by mid-evening and circumpolar from higher latitudes. They are among the sky's finest targets for binoculars or a low-power telescope eyepiece.
Featured Star
Caph (ฮฒ Cas), the yellow-white Delta Scuti variable at spectral type F2III-IV and 54.7 light-years distance, marks the western tip of Cassiopeia's W and is the first point of the constellation to rise in the northeast. At 54.7 light-years, it is close enough that its distance is known to better than 1% precision from Hipparcos parallax measurements.
Around This Date
- September 29, 1988Space Shuttle Discovery launched on mission STS-26, the Return to Flight mission after the Challenger disaster, successfully deploying a NASA Tracking and Data Relay Satellite.
- September 29, 2008SpaceX's Falcon 1 became the first privately developed liquid-fueled rocket to reach Earth orbit, on its fourth launch attempt, marking the beginning of the commercial orbital launch era.
Caph rises in the northeast before the rest of the W clears the horizon, patient, a little early, as if it has somewhere to be.