Epoch J2000 Equinox J2000
|Right ascension||03h 46m 19.57384s|
|Declination||23° 56′ 54.0812″|
|Apparent magnitude (V)||4.18|
|U−B color index||-0.41|
|B−V color index||-0.06|
|Variable type||β Cephei|
|Radial velocity (Rv)||6.2 km/s|
|Proper motion (μ)|| RA: 21.13 mas/yr |
Dec.: -43.65 mas/yr
|Parallax (π)||8.58 ± 0.37 mas|
|Distance||380 ± 20 ly |
(117 ± 5 pc)
|Surface gravity (log g)||4.0 cgs|
|Temperature||13,360 ± 340 K|
Merope is a blue-white B-type subgiant with a mean apparent magnitude of +4.14. Richard Hinckley Allen described the star as lucid white and violet. It has a luminosity of 630 times that of the Sun and a surface temperature of 14,000 kelvins. Merope's mass is roughly 4.5 solar masses and has a radius more than 4 times as great as the Sun's. It is classified as a Beta Cephei type variable star and its brightness varies by 0.01 magnitudes.
23 Tauri is the star's Flamsteed designation. The name Merope originates with Greek mythology; she is one of the seven daughters of Atlas and Pleione known as the Pleiades. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included Merope for this star. It is now so entered in the IAU Catalog of Star Names.
The Merope Nebula (also known as Tempel's Nebula and NGC 1435) is a diffuse reflection nebula in the Pleiades star cluster, surrounding the 4th magnitude star Merope. It was discovered on October 19, 1859 by the German astronomer Wilhelm Tempel. John Herschel, in his New General Catalogue (NGC), described it as a very faint nebula about the size of the full moon.
The Merope Nebula has an apparent magnitude starting at 13 and quickly dimming by a factor of about 15, making most of the nebula dimmer than magnitude 16. It is illuminated entirely by the star Merope, which is embedded in the nebula. It contains a bright knot, IC 349, about half an arcminute wide near Merope. It appears blue in photographs because of the fine carbon dust spread throughout the cloud. Though it was once thought the Pleiades formed from this and surrounding nebulae, it is now known that the Pleiades nebulosity is caused by a chance encounter with the cloud.
A small and unique nebula which is close to Merope was discovered by Edward Emerson Barnard in November 1890. It is naturally very bright but is almost hidden in the radiance of Merope.
Stars of Taurus