M13 - NGC 6205
DSS image of M13
Overlaid DSS image of M13, 30' x 30' with north at top and west to the right

Aladin viewer for the region around M13
Hercules Cluster
Bode 30, h 1968, GC 4230, C 1639+365

Type  Globular Cluster
Magnitude  5.9
Size  16.6'
Right Ascension  16h 41' 41.5"  (2000)
Declination  36° 27' 41" N
Constellation  Hercules
Description  !!eB, vRi, vgeCM, *11...
Classification  V
Observing Notes

Andrew Cooper
Jun 27, 2020    Waikoloa Quarry, HI (map)
8x42mm Nikon Prostaff 3S Binoculars @ 8x

Bright and easy to find on the line between ζHer and ηHer, closer to η, small, round, not resolved

Andrew Cooper
May 12, 2018    Kaʻohe, Mauna Kea, HI (map)
20cm f/6 Newtonian, Cave Astrola @ 102x

Beautiful, large, bright, fully resolved, 10' in diameter, a swarm of stars filling the eyepiece with a nicely concentrated core, easily one of the best objects in the sky

Andrew Cooper
Aug 19, 2017    Oregon Star Party, OR (map)
14.5" f/4.5 Starmaster @ 103x

A beautiful swarm of stars in the 14", large, 10' in diameter, bright, fully resolved, a coarse appearance created by a population of brighter members amoung fainter members, NGC6207 is visible 25' northeast

Andrew Cooper
Oct 27, 2006    Waimea, HI (map)
12x36 Canon Image Stabilized Binoculars

Good sized, bright! round, just starting to resolve, core is quite concentrated, great bino object! very east to locate in the Keystone of Hercules between Zeta and Eta Her

Andrew Cooper
May 26, 2006    Gila, NM (map)
46cm f/4.5 Deep Violet

Large! Bright! a beautiful swarm of stars filling the field at 175x, well concentrated with a very condensed core, several chains of brighter stars lead out into the periphery, NGC6207 is 27' away to the NE

Andrew Cooper
Jun 12, 1999    Pinal Peak, AZ (map)
20cm f/10 SCT

What can you say? one of the best globulars, large, fully resolved, many stars in the group seem to be a magnitude brighter than the average giving a salt and pepper look

Rev. T.W. Webb
May 19, 1885    Hardwick, Herefordshire, England (map)

Superb globular cluster, lying 1/3 from η towards ζ, finest of its class; just visible to naked eye. Halley discovered in 1714; M. was sure it contained no stars; but it is spangled with glittering points in a 5-1/2ft achromatic, and becomes a superb object in large telescopes. h. speaks of thousands of stars, 10 or 11 to 15 or 20 mg.; his father had estimated 14,000. Sm. call it an extensive and magnificent mass of stars, with the most compressed part densely compacted and wedged together under unknown laws of aggregation. h. describes 'hairy-looking curvilinear branches' well seen with 8-in. 'With' mirror; E. of Rosse who noticed this spiral tendency, detected also three dark 'lanes' or rifts in its interior, beautifully seen by Buffam with 9-in. 'With' mirror. I have also perceived them. Huggins spectrum continuous, but red end wanting. In Secchi's achr. the outliers, inconspicuous in ordinary instruments, fill a field of 8'. Klien has remarked that our understanding strives in vain to answer the inquiry, What is the object of these thousands on thousands suns? The mere aspect of this stupendous aggregation is indeed enough to make the mind shrink with a sense of the insignificance of our little world. Yet the Christian will not forget that, as it has been nobly said, He took the dust of this Earth, and with it He rules the universe!

The neighborhood is beautiful with a low power. A faint nebula, ±40' nf. [NGC6207]
― Celestial Objects for Common Telescopes, T. W. Webb, 1917

John Herschel
May 9, 1826    

Irregularly round with scattered stars in streaky masses and lines. Excessively condensed, to a perfect blaze. Stars from 11th to 20th magnitude; 7' or 8' diameter. Most magnificent object. The state of compression indicates a globular form not much denser at the centre.

Johann Elert Bode
Sep 9, 1774    Berlin Observatory, Germany (map)

On September 9,1774, with the 7-foot telesope, I found a very distinguishable nebulous star in Hercules between Eta and Zeta, which shows up as a rather vivid and round nebulous patch, which has a bright nucleus in its center. Actually, it is situated between two small stars, and is separated from the Northern one by 17.25' and from the Southern one by 16.75', as the third figure shows. From the star Zeta, I find with the heliometer a separation of 4°59', from Eta 2°29', from Pi 6°43', and from d 4°57'. It was only partially known to me at that time that Halley has observed a nebulous star in Hercules, and later I read in the Philosophical Transactions of the year 1716 that he had observed it in the year 1714 between Eta and Zeta at about 236 deg and 57 deg northern latitude; therefore, it has to been assumed that this must be the same one. Meanwhile Halley writes that the nebula is a bit closer to the star Zeta than to Eta. As I now find that it is situated closer to the star Eta than to Zeta, I don't know another reason responsible for this remarkable difference than a typing error at Halley, or his inacurate estimate of the position given by longitude and latitude.

Charles Messier
Jun 1, 1764    

Nebula without star, discovered in the belt of Hercules; it is round & brilliant, the center more brilliant than the edges, one perceives it with a telescope of one foot; it is near two stars, the one & the other of 8th magnitude, the one above and the other below it: the nebula was determined by comparing it with Epsilon Herculis. M. Messier has reported it on the Chart of the Comet of 1779, which was included in the volume of the Academy of that year. Seen by Halley in 1714. Seen again Jan. 5 & 30, 1781. It is reported in the English Celestial Atlas."
― Connaissance des Temps, 1781
Other Data Sources for M13
Nearby objects for M13
Credits...

Drawings, descriptions, and CCD photos are copyright Andrew Cooper unless otherwise noted, no usage without permission.

A complete list of credits and sources can be found on the about page

M13