LRD Watch DR1 · catalog object

LRDW J021737.70-051505.9

catalogSILVERmain classBH* channelcolour laneUDS (PRIMER UDS-1)

RA 02:17:37.701 34.4070894°

Dec −05:15:05.99 -5.2516631°

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
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 = 5.491.

At a glance

Tier: SILVER main class
Found by: BH* channel + colour lane
Redshift: 5.491 DJA grade 3, PRISM
Spectral shape: inconclusive de Graaff+25 criteria
F444W: 25.90 AB S/N 51, 0.16″ aperture
F277W − F444W: 1.53 mag strict redness
BH* share: 0.92 bhs_bb4200_b4; Δχ² galaxy 12.1, dwarf 29.6
Compactness: growth ratio 1.800 stars 2.245
Balmer break: 2.61 ± 0.67 F277W/F200W, red:Hb+OIII
Image vetting: half-stack no-coverage; no flags raised
Literature: 5 catalogue(s), 1 AGN paper(s) within 0.009″

Vetting

Image vettingpassed
Half-stack testno-coverage
Artifact risknone
Neighbournone
Extendedno

No vetting notes.

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	5.4906	rubies-uds41-v4_prism-clear_4233_41571.spec.fits
`z_vet`	Adopted by vetting	5.4906	zspec:dja:rubies-uds41-v4_prism-clear_4233_41571.spec.fits (pipeline z_vet 5.36 from pz:z_map (zpub 5.49 simbad.csv:RUBIES-UDS-41571 [2025A&A...702A..57H] agrees))
`z_phot`	Photometric (P(z) peak)	5.360	68%: 3.257–7.225
`z_bhs`	BH* channel fit	5.332	bhs_bb4200_b4
`z_agn`	Colour-lane fit	5.36	AGN-inclusive templates

Spectral checks

V-shape (spectrum): inconclusive
Star (spectrum): no
V-shape (photometry): passes β_UV −2.42, β_opt 2.47 at z_agn
Line in F410M: Ha 1 line-free optical band(s)
Line-ambiguous: yes
Settling verdict: inconclusive

Literature

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

Barro et al. (2026)
Kocevski et al. (2024)
Kokorev et al. (2024)
Leung et al. (2024)
Weibel et al. (2026), BH*-dominated sample
Hviding+2025 broad-line AGN

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	16.01	5.95	28.39	2.7	1.14
F115W	NIRCam wide	1.154	1.08	5.74	31.32	0.2	1.12
F150W	NIRCam wide	1.501	12.94	4.52	28.62	2.9	1.10
F200W	NIRCam wide	1.989	14.90	3.76	28.47	4.0	1.09
F277W	NIRCam wide	2.762	38.87	2.28	27.43	17.0	1.20
F356W	NIRCam wide	3.568	70.55	2.32	26.78	30.4	1.24
F410M	NIRCam medium	4.082	240.71	4.52	25.45	53.2	1.26
F444W	NIRCam wide	4.404	158.68	3.10	25.90	51.1	1.28

Provenance

Field: UDS (PRIMER UDS-1) (primeruds1)
Programmes: 01837 behind every mosaic the field measured
Pipeline rows merged: 3 all at one position
Detection pass: original
Release build: 33af9933d1cc 2026-10-17T14:29:44Z

Image sources

Band	Mosaic	Native pixel	Coverage
F090W	`jw01837-c1002_t000_nircam_clear-f090w_i2d.fits`	0.031″	1.00
F115W	`jw01837-c1002_t000_nircam_clear-f115w_i2d.fits`	0.031″	1.00
F150W	`jw01837-c1002_t000_nircam_clear-f150w_i2d.fits`	0.031″	1.00
F200W	`jw01837-c1002_t000_nircam_clear-f200w_i2d.fits`	0.031″	1.00
F277W	`jw01837-c1002_t000_nircam_clear-f277w_i2d.fits`	0.063″	1.00
F356W	`jw01837-c1002_t000_nircam_clear-f356w_i2d.fits`	0.063″	1.00
F410M	`jw01837-c1002_t000_nircam_clear-f410m_i2d.fits`	0.063″	1.00
F444W	`jw01837-c1002_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 J021737.70-051505.9.

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.