NGC 6099

GALAXYElliptical galaxy E

ILLUSTRATION FROM HUBBLE TYPE E · SURFACE BRIGHTNESS 24.7 MAG/ARCSEC² · MAJOR AXIS 1.42′ · AXIS RATIO 0.68 · POSITION ANGLE 139°

[

OVERVIEW

] GALAXY

NGC 6099 is an elliptical galaxy E in the constellation Hercules, 438.3 from Earth, shining at apparent magnitude 14.94 (). It is catalogued as 2MASX J16153554+1927123, LEDA 57640 and MCG +03-41-146, among 9 designations in total. It was discovered in 1867.

WHAT IT IS
Elliptical galaxy
HOW FAR
438.3

The light arriving now left it that long ago.

HOW BIG ON THE SKY
1.4

Small enough that the full Moon would cover it several times over.

HOW BRIGHT (B)

Faint: it takes a large telescope.

WHERE TO LOOK
Hercules

The patch of sky it sits in, as seen from Earth.

[

OBSERVING

] FROM WHERE YOU ARE

What it takes to see NGC 6099 for yourself. Everything in this part of the page is worked out for a real horizon, a real night and the equipment you say you have.

TONIGHT

Say where you are, and this line says when NGC 6099 is worth going out for.

[

THROUGH AN EYEPIECE

] 150 MM TELESCOPE · 25 MM EYEPIECE
NE
FIELD 1.08°

Near the faint end of this catalogue: a 300 mm telescope reaches it and a 150 mm one does not. NGC 6099 covers 1.4′ of sky against a of 1.08°, so at 48× it is a small patch, centred.

48×
1.08
1.25
13.0
SIZE ON THE SKY
1.4
FILLS OF THE FIELD
2% of the width
APPARENT MAGNITUDE ()
14.94 · too faint for this

NGC 6099 is not a point of light, so the limit above is the wrong one to hold it against: the same brightness spread over 1.4′ of sky is harder than a star of it, and goes first — spread out, it comes to 24.7 . Catalogued sizes are measured to a photographic contour, and the part an eye sees is usually smaller.

FIND IT ON THE SKY MAP ↗
[

APPARENT PLACE

] EQUINOX J2026.7

Where a telescope has to be pointed today, which is not quite where the catalogue records the object: the coordinate grid itself has turned since the year 2000 the catalogue is referred to.

RIGHT ASCENSION
DECLINATION
GRID TURNED SINCE
17.3
PROPER MOTION SINCE
none published

Computed for 2026-08-27 00:00 UT. No proper motion is published for NGC 6099, so nothing here moves the object; what separates this from the catalogued position above is the coordinate grid turning under it — about fifty arcseconds a year of precession since 2000, and the small nodding of the Earth’s axis on top of that. Aberration and refraction are not included, and neither is parallax; each is under an arcminute, which is also about as well as the catalogued position is known. The same figure for any date.

[

SPECTRUM

] ITS OWN LIGHT

A galaxy's spectrum is every star in it added together, so the gaps are the ones its commonest stars make. Where a line comes back as a spike instead, gas somewhere in the galaxy is being lit hard enough to glow on its own.

MADE OF
400500600700800900WAVELENGTH · NANOMETRESCa II H & KG band (CH)Mg I bFe I blendNa I DCa II triplet

Point at a labelled line — or an element above — to see which atom makes it and where it falls.

  • SHIFTED Every line above sits 3.0% redder than the wavelength its atom emits at, because NGC 6099 is receding. The pattern survives it — the whole barcode slides together, which is how the shift is measured in the first place.

SDSS DR18 optical spectra · spec-2206-53795-0133 · observed 2006-03-01. SDSS fibre, 3 arcseconds across. Resolving power R = 1,500 to 2,500; 3,823 reduced pixels rebinned onto 1,020 log-spaced display points and normalised to the median flux. Brightness is scaled to this spectrum’s own middle value, so the shape is the measurement and the height is not. The 7 lines named above are the ones that stand clear of the scatter and of the features around them; a spectrum at this sampling holds many more that it cannot separate. The samples themselves, as JSON, CSV or VOTable.

[

CATALOG DATA

] 15 FIELDS

The raw catalogue values, as the source published them, with the error bars where one was published — sorted by what each set of figures is about rather than by the order they happened to be stored in.

WHAT KIND OF THING IT IS

What the object is in itself, rather than how it happens to look from here.

Hubble type

HOW BRIGHT IT IS

What the light adds up to, measured through one filter at a time. A magnitude is a brightness on a backwards scale — the smaller the number, the brighter the object.

Apparent magnitude ()
Apparent magnitude ()
Apparent magnitude ( band)
Apparent magnitude ()
Surface brightness
24.73

WHERE IT IS AND HOW IT MOVES

Position, motion across the sky and the size it covers on it. These are measurements of the object as seen from here, so every one of them depends on where here is.

Radial velocity
8984
Redshift (z)
Redshift (z, CMB frame)
Major axis
1.42
Minor axis
0.97
139

WHEN IT WAS FOUND

Who first saw it, from where, and by what method.

Discovered by
Lewis A. Swift

OTHER NAMES AND NUMBERS

The identifiers other catalogues file this object under, for anyone joining this data to theirs.

OpenNGC type code
G
Wikidata item
Q1125671
[

ALSO KNOWN AS

] 9 DESIGNATIONS
  • 2MASX 2MASX J16153554+1927123
  • LEDA LEDA 57640
  • MCG MCG +03-41-146
  • NGC NGC 6099
  • PGC PGC 57640
  • SDSS SDSS J161535.55+192712.1
  • SDSS SDSS J161535.55+192712.2
  • SDSS SDSS J161535.56+192712.1
  • UGC UGC 10299 NED02
[

LOOK IT UP ELSEWHERE

] 4 SERVICES

Each link carries the identifier printed beside it. Nothing on this page is a measurement of our own, so a number that disagrees with one of these is worth reporting — and a service that has never catalogued this object under this name will say so plainly.

[

CITE THIS PAGE

] DR1

This page is live and its numbers move when an upstream refreshes, so the citation names the release the rows belong to rather than the day you read them. The release itself is frozen, republished as a bundle, and is what a data-availability statement should point at.

PLAIN TEXT
SpaceCatalog. NGC 6099 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/ngc-6099
BIBTEX
@misc{spacecatalog_ngc-6099,
  author       = {{SpaceCatalog}},
  title        = {{NGC 6099}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/ngc-6099},
  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from OpenNGC.}
}

The values above were taken from OpenNGC — CC-BY-SA-4.0. Citing this page does not replace citing that catalogue, and its licence is share-alike: the terms reach whatever you build from these rows.

[

RELATED OBJECTS

] 8 LINKED