# LRDW J021729.36-050657.2 — Cerin Amroth

Source: https://cerinamroth.com/jwst/lrds/dr1/j021729.36-050657.2/

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LRD Watch DR1 · catalog object

 

# LRDW J021729.36-050657.2

 

catalogSILVERmain classBH* channelcolour laneUDS (PRIMER UDS-2)

 

 

 

RA 02:17:29.370 34.3723733°

 

Dec −05:06:57.28 -5.1159122°

 

[SIMBAD within 2″](https://simbad.cds.unistra.fr/simbad/sim-coo?Coord=34.372373+-5.115912&Radius=2&Radius.unit=arcsec) · [ESASky](https://sky.esa.int/esasky/?target=34.372373%20-5.115912&fov=0.02&sci=true)

 

  

 

## 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 NE

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 = 7.197.  

 

## At a glance

 

TierSILVER main class

Found byBH* channel + colour lane

Redshift7.197 DJA grade 3, PRISM

Spectral shapeinconclusive de Graaff+25 criteria

F444W26.55 AB S/N 34, 0.16″ aperture

F277W − F444W2.00 mag strict redness

BH* share0.73 bhs_bb4200_b8; Δχ² galaxy 4.3, dwarf 9.4

Compactnessgrowth ratio 1.688 stars 2.271

Balmer break3.94 ± 1.14 F356W/F200W, blue:far-uv

Image vettinghalf-stack pass; no flags raised

Literature6 catalogue(s), 2 AGN paper(s) within 0.009″

 

 

 

 

 

## Vetting

 
- Image vettingpassed
- Half-stack testpass
- Artifact risknone
- Neighbournone
- Extendedno

 
- BH* channelevidence dchi2_gal=4.3 dchi2_bd=9.4
- BH* channelBH* share 0.73 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 | 7.1974 | rubies-uds31-v4_prism-clear_4233_981721.spec.fits
 | `z_vet` | Adopted by vetting | 7.1974 | zspec:dja_specz_grade3.csv:981721
 | `z_phot` | Photometric (P(z) peak) | 8.299 | 68%: 7.417–8.629
 | `z_bhs` | BH* channel fit | 7.486 | bhs_bb4200_b8
 | `z_agn` | Colour-lane fit | 8.30 | AGN-inclusive templates

 

 

 

 

 

## Spectral checks

 

V-shape (spectrum)inconclusive

Star (spectrum)no

V-shape (photometry)fails βUV −2.32, βopt −0.98 at z_agn

Line in F410MHb, OIII 1 line-free optical band(s)

Line-ambiguousyes

Settling verdictLRD-like continuum

 

 

 

## Literature

 

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

 
- Barro et al. (2026)
- de Graaff et al. (2025)
- Kocevski et al. (2024)
- Kokorev et al. (2024)
- Leung et al. (2024)
- Weibel et al. (2026), BH*-dominated sample
- Hviding+2025 broad-line AGN
- Yanagisawa+2026 (ATLAS I) 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 | 1.53 | 4.82 | 30.94 | 0.3 | 1.15
 | F115W | NIRCam wide | 1.154 | 6.06 | 4.59 | 29.44 | 1.3 | 1.12
 | F150W | NIRCam wide | 1.501 | 12.04 | 3.85 | 28.70 | 3.1 | 1.11
 | F200W | NIRCam wide | 1.989 | 11.01 | 3.18 | 28.80 | 3.5 | 1.09
 | F277W | NIRCam wide | 2.762 | 13.81 | 2.03 | 28.55 | 6.8 | 1.20
 | F356W | NIRCam wide | 3.568 | 43.26 | 1.94 | 27.31 | 22.2 | 1.23
 | F410M | NIRCam medium | 4.082 | 80.29 | 3.89 | 26.64 | 20.6 | 1.26
 | F444W | NIRCam wide | 4.404 | 86.85 | 2.58 | 26.55 | 33.6 | 1.27
 | F1280W | MIRI | 12.809 | 78.60 | 61.34 | 26.66 | 1.3 | 3.12
 | F1500W | MIRI | 15.048 | 123.37 | 75.95 | 26.17 | 1.6 | 3.86

 

 

 

## Provenance

 

 FieldUDS (PRIMER UDS-2) (`primeruds2`) Programmes`01837, 07814` behind every mosaic the field measured Pipeline rows merged3 all at one position Detection passoriginal 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 J021729.36-050657.2.

 

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](https://cerinamroth.com/jwst/lrds/dr1/).

 

 [← LRDW J021729.32-021228.1](https://cerinamroth.com/jwst/lrds/dr1/j021729.32-021228.1/)[LRDW J021729.66-051330.7 →](https://cerinamroth.com/jwst/lrds/dr1/j021729.66-051330.7/)