![]() In the chart below, Hokulei (Capella) has risen to an altitude higher than the NCP directly above it, halfway between it and the top of the chart, is the cluster of stars called Makali‘i (Pleiades).ģ. Above it is the bright star Almach in Pegasus, but a closer alignment on the meridian is with the relatively faint Alpha Trianguli, the apex of a tall triangle, leaning to the left, just above Almach. Less than two hours after Polo‘ula (Caph) crosses the meridian, the wide M of ‘Iwakeli‘i has rotated left, and the last star in the M (the bottom star of the right stem), the relatively faint Segin, is crossing the meridian. Segin in Cassiopeia (01h 54.4m) and Alpha Trianguli (01h 53.1 m). Note: For print versions of the night-sky charts that would use less toner (like the first chart at the top of this webpage), you can convert the dark sky chart with light stars to one with a white sky and dark stars by dragging the image onto your desktop and using the Invert function in a graphic program like Photoshop (Image>Adjustments>Invert) to reverse the image.Ģ. The bright star to the right of the NCP, directly above NE, is Hokulei (Capella) which rose earlier between NE and NE by N. (In the configuration of the Great Square above the NCP, the bottom right corner of the square is Alpheratz.) Higher up, near the top of the chart is Scheat, the star at the top right corner of the Great Square. In the chart below, as M circles above Hokupa‘a (the North Star) and the NCP, and Polo‘ula crossing the meridian aligns with the star Alpheratz, the brightest star of Ka Lupe o Kawelo (the Great Square of Pegasus). Polo‘ula is the bottom star of the left stem in the configuration of ‘Iwakeli‘i (Cassiopeia) that looks like a wide M. Polo‘ula (Caph) in ‘Iwakeli‘i (Cassiopeia) (00h 9.2m) and Alpheratz in Ka Lupe o Kawelo (in the Great Square of Pegasus) (00h 8.4m). Thus, Segin in Cassiopeia, with an RA of 01h 54.4m, will arrive at the meridian about an hour and 45 minutes after Polo‘ula (Caph in Cassiopeia), with an RA of 00h 9.2m.įor notes on Hawaiian star names, see Hawaiian Star Lines.ġ. You can calculate how long it will take a star to reach the meridian after another star by subtracting the RA of the second star from the RA of the first. ![]() Two stars with the same RA will cross the meridian together. (See “ The Celestial Sphere.”) The closer the RA numbers are for two stars, the more closely they will align at the meridian. RA gives one of two coordinates to fix the position of a star on the celestial sphere. The numbers in parentheses after the star names below are Right Ascension (RA), given in hours (h) and minutes (m). In different months and seasons of the year, different portions of the sequence are visible at night. In daylight or under cloudy conditions at night, you would not be able to see some or all of the sequence since the sky would be hidden by light or clouds, although the stars would be moving in this sequence whether you can see them or not. The sky is depicted without regard to night or day. The night sky charts below depict the alignment of nine star meridian pointers to North. Holopuni, or Kochab, in the chart above) are circumpolar, neither rising nor setting. Hawai‘i is situated between the latitudes of 19° N and 22°N, with its midpoint at 20.5° N.)īecause the NCP is 21 degrees above the horizon, stars within 21 degrees of the NCP (e.g. ![]() (See “ The Celestial Sphere” for an explanation of this phenomenon. The distance of the NCP above the horizon is equivalent to the latitude of the observer north of the equator. Hokupa‘a, the North Star, appears less than a degree away from the NCP. The meridian (dotted line perpendicular to the horizon) is an imaginary line from the North Celestial Pole (NCP) to the South Celestial Pole (SCP), passing through the Zenith, the point in the sky directly overhead and intersecting the horizon perpendicularly at due North and due South.īecause of the earth’s 24-hour rotation, the sky appears to be rotating around the NCP, counter-clockwise, from right to left, returning to its starting point every 24 hours stars cross the meridian during this rotation.īecause Honolulu is at 21 N latitude, the North Celestial Pole (NCP) is 21 degrees above the horizon. In the diagram below, Manōkalanipō (Alpheratz, in the Great Square of Pegasus) and Polo‘ula (Caph in ‘Iwakeli‘i, or Cassiopeia) align on the meridian, which intersects the horizon line perpendicularly at North, after passing through the North Celestial Pole (NCP). Meridian Pointers to North Meridian pointers to north are pairs of stars that cross the meridian together and point down to North on the horizon. ![]()
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