LRD Watch DR1 · catalog object

LRDW J021731.38-050622.4

catalogTENTATIVEBH* channelUDS (PRIMER UDS-2)

RA 02:17:31.381 34.3807547°

Dec −05:06:22.41 -5.1062237°

SIMBAD within 2″ · ESASky

Images

F090W image, 3.2 arcsec across, north up — F090W0.03″ px

F115W image, 3.2 arcsec across, north up — F115W0.03″ px

F150W image, 3.2 arcsec across, north up — F150W0.03″ px

F200W image, 3.2 arcsec across, north up — F200W0.03″ px

F277W image, 3.2 arcsec across, north up — F277W0.06″ px

F356W image, 3.2 arcsec across, north up — F356W0.06″ px

F410M image, 3.2 arcsec across, north up — F410M0.06″ px

F444W image, 3.2 arcsec across, north up — F444W0.06″ px

Colour composite: F444W red, F356W green, F277W blue, 3.2 arcsec across, north up — compositebar 1″

3.2″ across, north up, east left, resampled from the deepest mosaic covering the object in each band; ticks mark the catalogue position. Each band is stretched on its own noise; the composite shares one flux scale, so its colour is real.

Spectral energy distribution

NIRCam wide
NIRCam medium
MIRI
2σ upper limit (S/N < 2)

Aperture fluxes in a 0.16″-radius circle, not corrected to total; the values are in the photometry table below. The gold line marks the Balmer limit (3646 Å rest) at z = 5.179.

At a glance

Tier: TENTATIVE
Found by: BH* channel
Redshift: 5.18 BH* fit
Spectral shape: no labelled spectrum
F444W: 26.50 AB S/N 27, 0.16″ aperture
F277W − F444W: not in the colour lane
BH* share: 0.76 bhs_bb5400_b8; Δχ² galaxy 2.4, dwarf 40.6
Compactness: growth ratio 2.060 stars 2.271
Balmer break: 3.24 ± 0.93 F277W/F200W, red:Hb+OIII
Image vetting: half-stack pass; no flags raised
Literature: 1 catalogue(s), 0 AGN paper(s) within 0.048″

Vetting

Image vettingnot applicable
Half-stack testpass
Artifact risknone
Neighbournone
Extendedno

BH* channelevidence dchi2_gal=2.4 dchi2_bd=40.6
BH* channelBH* share 0.76 below 0.8 (composite)

Redshifts

Each redshift keeps its own column. Photometric redshifts of little red dots are unreliable: against spectra, about a third of AGN-template redshifts (z_agn; 31 of 95 in the last purity run) and about half of galaxy-template redshifts at z > 3 were catastrophic outliers (methods Section 8).

Column	What it is	z	Source
`z_spec`	Spectroscopic, DJA grade 3	—	—
`z_vet`	Adopted by vetting	5.1788	bhstar:bhs_bb5400_b8
`z_phot`	Photometric (P(z) peak)	—	not fitted
`z_bhs`	BH* channel fit	5.179	bhs_bb5400_b8
`z_agn`	Colour-lane fit	—	—

Spectral checks

V-shape (spectrum): no labelled spectrum
Star (spectrum): no spectrum
V-shape (photometry): not measurable β_UV not measured, β_opt not measured at z_agn
Line in F410M: Ha 1 line-free optical band(s)
Line-ambiguous: yes
Settling verdict: not evaluated

Literature

Published objects within 1″ of this position. A match is a positional recovery, not an adopted classification.

Barro et al. (2026)

Photometry

Circular aperture of radius 0.16″ at each band's native resolution, background from a 0.40–0.65″ annulus, programmes combined by inverse variance. For a point source multiply by the field's aperture correction (r = 0.16″ → 0.70″). Grey rows are below S/N 2.

Band	Instrument	Pivot (µm)	f (nJy)	σ (nJy)	AB mag	S/N	Ap. corr.
F090W	NIRCam wide	0.902	26.57	7.03	27.84	3.8	1.15
F115W	NIRCam wide	1.154	19.65	6.49	28.17	3.0	1.12
F150W	NIRCam wide	1.501	15.03	5.38	28.46	2.8	1.11
F200W	NIRCam wide	1.989	16.18	4.56	28.38	3.5	1.09
F277W	NIRCam wide	2.762	52.43	2.85	27.10	18.4	1.20
F356W	NIRCam wide	3.568	59.37	2.74	26.97	21.6	1.23
F410M	NIRCam medium	4.082	124.15	5.07	26.16	24.5	1.26
F444W	NIRCam wide	4.404	90.85	3.37	26.50	26.9	1.27
F1280W	MIRI	12.809	116.00	49.64	26.24	2.3	3.12
F1500W	MIRI	15.048	30.55	61.63	27.69	0.5	3.86

Provenance

Field: UDS (PRIMER UDS-2) (primeruds2)
Programmes: 01837, 07814 behind every mosaic the field measured
Pipeline rows merged: 1 all at one position
Detection pass: original
Release build: 33af9933d1cc 2026-10-17T14:29:44Z

Image sources

Band	Mosaic	Native pixel	Coverage
F090W	`jw01837-c1001_t000_nircam_clear-f090w_i2d.fits`	0.031″	1.00
F115W	`jw01837-c1001_t000_nircam_clear-f115w_i2d.fits`	0.031″	1.00
F150W	`jw01837-c1001_t000_nircam_clear-f150w_i2d.fits`	0.031″	1.00
F200W	`jw01837-c1001_t000_nircam_clear-f200w_i2d.fits`	0.031″	1.00
F277W	`jw01837-c1001_t000_nircam_clear-f277w_i2d.fits`	0.063″	1.00
F356W	`jw01837-c1001_t000_nircam_clear-f356w_i2d.fits`	0.063″	1.00
F410M	`jw01837-c1001_t000_nircam_clear-f410m_i2d.fits`	0.063″	1.00
F444W	`jw01837-c1001_t000_nircam_clear-f444w_i2d.fits`	0.063″	1.00

Cite

Anderson, Jordan (2026). LRD Watch DR1: little red dot candidates from an independent search of public JWST imaging (Version DR1) [Data set]. Cerin Amroth Research. Zenodo. https://doi.org/10.5281/zenodo.23062632 Object LRDW J021731.38-050622.4.

CC BY 4.0. Please also acknowledge the JWST programmes that took the data. LRD Watch DR1 is a vetted candidate catalogue, not a complete census: it has no selection function and cannot on its own give number densities. About the release.