M4 = NGC6121 (16h 23.7m -2624, 5.9 mag)
This large globular cluster was discovered by de Cheseaux in 1746 and Messier observed it on May 8, 1764. It has very loose structure and contains an unusual band of bright stars across its centre.
M4 is a globular cluster that lies in the constellation of Scorpius. It is located about 7,000 light-years from the Earth. This makes M4 one of the closest of the globular clusters. It is also one of the most open, or loose globular clusters.
M4
0.042
ScI (see for instance 5671) appears in mid-F-type stars and grows monotonically toward later types. From late G-type onwards, a positive luminosity effect is visible for supergiants.
M4 (globular cluster)
M6 The Butterfly Cluster (open cluster)
M7 Ptolemy's Cluster (open cluster)
M80 (globular cluster) ...
M4 is located just west of Antares, roughly half way to sigma Scorpii.
M6 (NGC 6405) is the second-best cluster of the constellation (after M7). This is an open cluster which sometimes bears the name "The Butterfly Cluster".
M4 SLBMM4 TollM4 Western Motorway
M5M50M50 motorway
M50 motorway (Great Britain)M50 motorway (Ireland)M50 Super Sherman ...
M4 Carbine
The M4 Carbine is a family of firearms tracing its lineage back to earlier carbine versions of the M16 rifle, all based on the original AR-15 made by ArmaLite....
with SOPMOD
SOPMOD ...
The luminosity of main sequence stars is roughly proportional to their mass to the fourth power, i.e. L ∝ M4.
Study Astronomy Online at Swinburne University
All material is Swinburne University of Technology except where indicated.
9 +23 29 41 M4.5IIIa 5.70 1.56 6047 16 13 15.4 + 5 1 16 gK5 5.48 1.47 6065 16 15 28.6 +18 48 30 K3III 5.69 1.12 6111 16 24 10.7 + 6 56 54 A2pSr: 5.85 -0.01 6119 U HER 16 25 47.6 +18 53 33 M7IIIe 6.70 0.00 6123 16 25 24.0 +37 23 39 A5V 5.52 0.
M4 (NGC 6121, globular cluster)
M6 (NGC 6405, Butterfly Cluster)
M7 (NGC 6475, Ptolemy's Cluster)
M8 (NGC 6523, Lagoon Nebula)
M11 (NGC 6705, Wild Duck Cluster)
M13 (NGC 6205, Great Cluster in Hercules)
M16 (NGC 6611) ...
Yet the contrast is nice, as fourth magnitude (3.88) Kappa is a blue-white class B (B6) giant, whereas the closer of the two, 6 Dra, is a fifth magnitude (4.95) red class M (M4) giant. (4 Dra is a bit warmer fifth magnitude K3 giant).
Since the luminosity of a star varies like M3 or M4, the lifetime of a star on the main sequence varies like t=const*M/L=k/L0.7.
You can use the observed mass-luminosity relation L = M4 in the life zone boundary relation given above to put everything in terms of just the mass. Substituting M4 for the luminosity L, the 1.4-solar mass star's life zone is between 1.76 A.U. and 2.
This cool and dim, main sequence red dwarf (M4.1 Vn) has almost a third of Sol's mass, a tenth of its diameter, but only 33/100,000th of its luminosity.
A White dwarf star: (circled) in the globular cluster M4.
The star is now a white dwarf, a stable star with no nuclear fuel. It radiates its left-over heat for billions of years.
Alkali amphiboles are divided into two groups based upon M4 and A site occupancies. If the M4 site contains <0.5 (Na+K) and there is no Na in the A site, the mineral is considered a low-Na alkali amphibole. If the M4 site contains >0.
In August of 1995, this camera observed more than 75 white dwarfs in the globular cluster M4 in the constellation Scorpius.
20 (a) The globular cluster M4, as seen through a large ground-based telescope on Kitt Peak Mountain. This is the closest globular cluster to us, at 2100 pc away; it spans some 16 pc.
The planet is located in the globular star cluster M4, about 5,600 light years from Earth in the constellation Scorpius.
Thousands of stars are packed tightly in the central regions of M4, one of the closest globular clusters to Earth. It is more than 6,000 light-years away. Most of its stars are old and relatively faint.
The globular cluster in which the system resides, M4, is approximately 5,600 light-years away in the constellation Scorpius.
6 and spectral classification M4 III. Its +6.4 magnitude white companion star (spectral classification A3) lies about 2 arcminutes away at an angle of 128 degrees from the main star, and can be observed with binoculars.
: (circled) in the globular cluster M4.
The star is now a , a stable star with no nuclear fuel. It radiates its left-over heat for billions of years.
White dwarfs in the globular cluster M4. The white dwarfs (circled) are about 12 billion years old, the oldest yet observed and at 30th magnitude, also the faintest. For more details read the press release.
The Chandrasekhar Limit ...
M4, NGC 6121, globular cluster in Scorpius
UKS 4. Antares and the Rho Ophiuchi dark cloud (Scorpius/Ophiuchus)
UKS 10. NGC 6334 and NGC 6357 in the Milky Way
UKS 30. The Antares nebula
UKS 38. Star clouds and Dust in Scorpius ...
As it is nearby, M4 is one of the largest, brightest globular clusters in the sky, visible even with binoculars. As a bonus, it is especially easy to find since it is located only 1.5 degrees west of Antares.
In addition, the ages of the extrasolar planets differ from one another and from that of the solar planets; the oldest planet, discovered in the globular cluster M4 in 2003, is believed to have been formed 12.
 See also: Star, Light, Sky, Constellation, Planet
  
|
RSS
