Catalogue record

HR 2421

24Gam Gem

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This opens a form with this exact target selected. Review your date, location and observing constraints before calculating. Nothing is calculated or saved by following the link.

A bounded starter sample: 50 bright-star records from HEASARC BSC5P, including 23 records with identified double-star components and historical separations, plus 108 OpenNGC deep-sky records associated with Messier numbers.

These are static catalogue measurements, not current sky positions or a complete census. Double-star records may describe the same pair; a pair is not necessarily a gravitationally bound binary. Separation dates and companion position angles are not available.

Missing measurements are unknown, not zero. Sizes can come from different wavelength bands and do not guarantee an object’s visible extent. No observability or equipment-resolution prediction is made here.

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Stable source identifier: bsc5p:hr2421
Source object type: star
Catalogue right ascension: 99.4279 degrees
Catalogue declination: 16.3992 degrees
Recorded magnitude: 1.93 · V (BSC5P; retain code/uncertainty flags)
Uncertainty flag: None reported; source code: None reported
Catalogue major / minor axes: Not reported / Not reported
Components: AC
Historical component separation: 143.5 arcsec
Separation measurement epoch: Not reported
Companion position angle: Not reported

Coordinate interpretation

Verified coordinate frame: FK5
Frame equinox: J2000.0
Catalogue reference epoch: Julian year 2000.0
Individual observation epoch: Not reported
RA proper motion, including cosine of declination: 0.042 arcsec/year
Declination proper motion: -0.042 arcsec/year

The reference epoch describes when the catalogue position is expressed. It does not establish when individual observations were taken. Equinox describes the orientation of the coordinate axes.

Angular proper motion is available for a bounded calculation, but has not been applied here. No distance, radial velocity, perspective acceleration or companion orbit is inferred.

This page shows unchanged catalogue coordinates. It does not calculate current sky positions or observability.

Source and reuse: bsc5p

Hoffleit and Warren (1991), Bright Star Catalog, 5th revised preliminary edition; NASA/GSFC HEASARC

Original source / pinned release · NASA government-works; HEASARC free-use policy

Credit Hoffleit and Warren and NASA/GSFC HEASARC when reusing these records. Retain the source flags and historical measurement limitations.

Selection: Vmag <= 2.0, excluding 14 documented nonstellar HR identifiers
Retrieved: 2026-10-01T21:40:09.869946+00:00
Reviewed subset SHA256: 7fe926d80b535f9422ca81f8f3fee1d6422de29adaecfbd2f14b1a93fe5134b9

Original file hashes

bsc5p.tdat: e2b2f8e9d615426f9478f88061235976143d49d8b25c6c15df3f3661c7095b53

Coordinate-frame evidence

CDS VizieR · V/50/catalog

Exact source identifiers matched: 50. Evidence retrieved: 2026-10-01.

Pinned response SHA256: a3f83273ccaecf913a0d8e077413062c20ce1fc01ce890c80615a9572d5f1be9

Original source fields and flags

Original strings preserve missing values, photometric flags and per-field source codes. Blank means no value was supplied. No proper motion or companion position is calculated here.

ads: Not supplied
ads_comp: Not supplied
alt_name: 24Gam Gem
bii: 4.4526
bv_color: 0
bv_uncert: Not supplied
cdec: +162357
cdec_1950: +162635
class: 2304
cra: 063742.7
cra_1950: 063449.5
dec: 16.3992
dec_1900: 16.48333333347
dec_1950: 16.443
dm_cat: BD
dm_num: +16 1223
fk5: 251
glat: 4.45
glon: 196.77
hd: 47105
hr: 2421
ir_flag: I
lii: 196.774
m_cnt: 3
m_id: AC
m_mdiff: 9
m_sep: 143.5
multiple: W
name: HR 2421
note: *
par_code: Not supplied
parallax: 0.033
pmdec: -0.042
pmra: 0.042
ra: 99.4279
ra_1900: 97.98374999364
ra_1950: 98.7063
radvel: -13
radvel_comm: SB
ri_code: Not supplied
ri_color: -0.01
rotvel: 32
rotvel_comm: Not supplied
rotvel_uncert: Not supplied
sao: 95912
spect_code: Not supplied
spect_type: A0IV
ub_color: 0.04
ub_uncert: Not supplied
var_id: Not supplied
vmag: 1.93
vmag_code: Not supplied
vmag_uncert: Not supplied