NGC 6530
Open cluster in the constellation Sagittarius
title: "NGC 6530" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["open-clusters", "sagittarius-(constellation)", "ngc-objects"] description: "Open cluster in the constellation Sagittarius" topic_path: "general/open-clusters" source: "https://en.wikipedia.org/wiki/NGC_6530" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Open cluster in the constellation Sagittarius ::
::data[format=table title="Infobox open cluster"]
| Field | Value |
|---|---|
| name | NGC 6530 |
| image | M8_rvb.jpg |
| caption | NGC 6530 (right) and the Lagoon Nebula |
| credit | |
| epoch | J2000 |
| constellation | Sagittarius |
| ra | |
| dec | |
| dist_ly | 1336 pc () |
| 1325 pc | |
| appmag_v | 4.6 |
| size_v | |
| radius_ly | |
| mass_msol | |
| age | 4–6 Myr |
| notes | H II region |
| names | Cr 362 |
| :: |
| name = NGC 6530 | image = M8_rvb.jpg | caption = NGC 6530 (right) and the Lagoon Nebula | credit = | epoch = J2000 | constellation = Sagittarius | ra = | dec = | dist_ly = 1336 pc () 1325 pc | dist_pc = | appmag_v = 4.6 | size_v = | radius_ly = | mass_msol = | age = 4–6 Myr | notes = H II region | names = Cr 362
NGC 6530 is a young open cluster of stars in the southern constellation of Sagittarius, located some 4,300 light years from the Sun. It exists within the H II region known as the Lagoon Nebula, or Messier 8, and spans an angular diameter of . The nebulosity was first discovered by G. B. Hodierna prior to 1654, then re-discovered by J. Flamsteed circa 1680. It was P. Loys who classified it as a cluster in 1746, as he could only resolve stars. The following year, G. Le Gentil determined it was both a nebula and a cluster.
::figure[src="https://upload.wikimedia.org/wikipedia/commons/3/3f/Hubble_NGC6530.jpg" caption="Hubble"] ::
The brightest six members of the cluster are visible in 10×50 binoculars at magnitudes 6.9 and fainter, while fifteen evenly distributed stars are visible with a 25×100 pair. More than two dozen stars are visible in an amateur telescope. The average extinction AV due to interstellar dust along the line of sight from the Earth is , with a color excess E(B−V) of .
In total, 3,675 stars in the field of NGC 6530 have been catalogued as candidate members, with the likely members being 2,728. As of 2019, 652 stars have been confirmed as members: 333 of these are classical T Tauri-type variable stars showing a near infrared emission excess, while the remainder are weak T Tauri stars showing a photospheric excess. Candidate stars appear in two main groups at the cluster core and the Sagittarius "Hourglass nebula", with other smaller concentrations. Two such minor concentrations are associated with the stars 7 Sgr and HD 164536.
Age estimates for the members shows a spread in values that suggests more than one burst of star formation. Initial star formation began up to 15 million years ago, but the bulk formed in the last 1–2 million years near the cluster center. Astrometric data suggests the parent molecular cloud collided with the galactic plane some four million years ago, which may have triggered the star formation. The dispersion of velocities for a sample of stars in the cluster suggests it may be gravitationally unbound and there is evidence the star population is expanding, particularly to the north and south.
References
| title=Turn Left at Orion: Hundreds of Night Sky Objects to See in a Home Telescope – and How to Find Them | first1=Guy | last1=Consolmagno | first2=Dan M. | last2=Davis | year=2019 | page=147 | isbn=9781108457569 | publisher=Cambridge University Press | url=https://books.google.com/books?id=D2JjDwAAQBAJ&pg=PA147 }}
| title=A Guide to Hubble Space Telescope Objects, Their Selection, Location, and Significance | first1=James L. | last1=Chen | first2=Adam | last2=Chen | date=2015 | page=67 | isbn=9783319188720 | publisher=Springer International Publishing | url=https://books.google.com/books?id=qj0wCgAAQBAJ&pg=PA67 }}
| title=Open clusters. III. Fundamental parameters of B stars in NGC 6087, NGC 6250, NGC 6383, and NGC 6530 B-type stars with circumstellar envelopes | last1=Aidelman | first1=Y. | last2=Cidale | first2=L. S. | last3=Zorec | first3=J. | last4=Panei | first4=J. A. | display-authors=1 | journal=Astronomy & Astrophysics | volume=610 | id=A30 | pages=18 | date=February 2018 | doi=10.1051/0004-6361/201730995 | arxiv=1711.01311 | bibcode=2018A&A...610A..30A | s2cid=59375851 }}
| title=Stellar clusters in the inner Galaxy and their correlation with cold dust emission | last1=Morales | first1=Esteban F. E. | last2=Wyrowski | first2=Friedrich | last3=Schuller | first3=Frederic | last4=Menten | first4=Karl M. | display-authors=1 | journal=Astronomy & Astrophysics | volume=560 | pages=A76 | year=2013 | doi=10.1051/0004-6361/201321626 | arxiv=1310.2612 | bibcode = 2013A&A...560A..76M | s2cid=118422539 }}
| title=Sky Vistas, Astronomy for Binoculars and Richest-Field Telescopes | first1=Craig | last1=Crossen | first2=Gerald | last2=Rhemann | date=2012 | page=46 | isbn=9783709106266 | publisher=Springer Vienna | url=https://books.google.com/books?id=3vELBwAAQBAJ&pg=PA46 }}
| title=The Gaia-ESO Survey: asymmetric expansion of the Lagoon Nebula cluster NGC 6530 from GES and Gaia DR2 | last1=Wright | first1=Nicholas J. | last2=Jeffries | first2=R. D. | last3=Jackson | first3=R. J. | last4=Bayo | first4=A. | last5=Bonito | first5=R. | last6=Damiani | first6=F. | last7=Kalari | first7=V. | last8=Lanzafame | first8=A. C. | last9=Pancino | first9=E. | last10=Parker | first10=R. J. | last11=Prisinzano | first11=L. | last12=Randich | first12=S. | last13=Vink | first13=J. S. | last14=Alfaro | first14=E. J. | last15=Bergemann | first15=M. | last16=Franciosini | first16=E. | last17=Gilmore | first17=G. | last18=Gonneau | first18=A. | last19=Hourihane | first19=A. | last20=Jofré | first20=P. | last21=Koposov | first21=S. E. | last22=Lewis | first22=J. | last23=Magrini | first23=L. | last24=Micela | first24=G. | last25=Morbidelli | first25=L. | last26=Sacco | first26=G. G. | last27=Worley | first27=C. C. | last28=Zaggia | first28=S. | journal=Monthly Notices of the Royal Astronomical Society | volume=486 | issue=2 | pages=2477–2493 | display-authors=1 | date=June 2019 | doi=10.1093/mnras/stz870 | doi-access=free | arxiv=1903.12176 | bibcode=2019MNRAS.486.2477W }}
| title=The Gaia-ESO Survey: Age spread in the star forming region NGC 6530 from the HR diagram and gravity indicators | last1=Prisinzano | first1=L. | last2=Damiani | first2=F. | last3=Kalari | first3=V. | last4=Jeffries | first4=R. | last5=Bonito | first5=R. | last6=Micela | first6=G. | last7=Wright | first7=N. J. | last8=Jackson | first8=R. J. | last9=Tognelli | first9=E. | last10=Guarcello | first10=M. G. | last11=Vink | first11=J. S. | last12=Klutsch | first12=A. | last13=Jiménez-Esteban | first13=F. M. | last14=Roccatagliata | first14=V. | last15=Tautvaišienė | first15=G. | last16=Gilmore | first16=G. | last17=Randich | first17=S. | last18=Alfaro | first18=E. J. | last19=Flaccomio | first19=E. | last20=Koposov | first20=S. | last21=Lanzafame | first21=A. | last22=Pancino | first22=E. | last23=Bergemann | first23=M. | last24=Carraro | first24=G. | last25=Franciosini | first25=E. | last26=Frasca | first26=A. | last27=Gonneau | first27=A. | last28=Hourihane | first28=A. | last29=Jofré | first29=P. | last30=Lewis | first30=J. | last31=Magrini | first31=L. | last32=Monaco | first32=L. | last33=Morbidelli | first33=L. | last34=Sacco | first34=G. G. | last35=Worley | first35=C. C. | last36=Zaggia | first36=S. | display-authors=1 | journal=Astronomy & Astrophysics | volume=623 | id=A159 | pages=22 | date=March 2019 | doi=10.1051/0004-6361/201834870 | arxiv=1901.09589 | bibcode=2019A&A...623A.159P | s2cid=119394685 }}
| title=Wide-area photometric and astrometric (Gaia DR2) study of the young cluster NGC 6530 | last1=Damiani | first1=F. | last2=Prisinzano | first2=L. | last3=Micela | first3=G. | last4=Sciortino | first4=S. | display-authors=1 | journal=Astronomy & Astrophysics | volume=623 | id=A25 | pages=21 | date=March 2019 | doi=10.1051/0004-6361/201833877 | arxiv=1812.11402 | bibcode=2019A&A...623A..25D | s2cid=119428764 }}
| title=Interstellar Extinction in the Direction of the Young Open Cluster NGC 6530 | display-authors=1 | last1=Topasna | first1=G. A. | last2=Jones | first2=R. H. | last3=Kaltcheva | first3=N. T. | journal=Publications of the Astronomical Society of the Pacific | volume=132 | issue=1010 | id=044301 | pages=14 | date=February 2020 | doi=10.1088/1538-3873/ab6aba | bibcode=2020PASP..132d4301T | doi-access=free }}
| title=The orbits of open clusters in the Galaxy | last1=Wu | first1=Zhen-Yu | last2=Zhou | first2=Xu | last3=Ma | first3=Jun | last4=Du | first4=Cui-Hua | display-authors=1 | journal=Monthly Notices of the Royal Astronomical Society | volume=399 | issue=4 | pages=2146–2164 | date=November 2009 | arxiv=0909.3737 | bibcode=2009MNRAS.399.2146W | doi=10.1111/j.1365-2966.2009.15416.x | doi-access=free | s2cid=6066790 }}
| title= Kinematics in Young Star Clusters and Associations with Gaia DR2 | display-authors=1 | last1=Kuhn | first1=Michael A. | last2=Hillenbrand | first2=Lynne A. | last3=Sills | first3=Alison | last4=Feigelson | first4=Eric D. | last5=Getman | first5=Konstantin V. | journal=The Astrophysical Journal | volume=870 | issue=1 | pages=32| year=2018 | arxiv=1807.02115 | bibcode=2019ApJ...870...32K | doi=10.3847/1538-4357/aaef8c | s2cid=119328315 | doi-access=free }}
References
::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::