---
title: "19 Lyn A"
url: "https://spacecatalog.org/object/hd-57103"
release: "DR1"
licence: "CC-BY-SA-4.0"
citation: "SpaceCatalog. 19 Lyn A [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-57103"
---

# 19 Lyn A

19 Lyn A is a B8V blue-white main-sequence [star](https://spacecatalog.org/stars) in the constellation [Lynx](https://spacecatalog.org/constellation/lynx), shining at apparent magnitude 5.80 (V). Other catalogues list it as HD 57103, HIP 35785 and HR 2784.

## At a glance

- **WHAT IT IS:** Blue-white main-sequence star
- **HOW BRIGHT (V):** 5.80 — Bright enough for the naked eye, under a sky dark enough.
- **WHERE TO LOOK:** [Lynx](https://spacecatalog.org/constellation/lynx) — The patch of sky it sits in, as seen from Earth.

## Properties

| Quantity | Value |
| --- | --- |
| CLASS | B8V blue-white main-sequence star |
| MASS | 3.68 M☉ — Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: above 7,500 K GSP-Phot's temperature and extinction are degenerate |
| APPARENT MAGNITUDE (V) | 5.80 |
| CONSTELLATION | Lynx |
| RIGHT ASCENSION (J2000) | 07h 22m 52.1s |
| DECLINATION (J2000) | +55° 16′ 53.0″ |

## Catalogue data

### WHAT KIND OF THING IT IS

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

| Field | Value |
| --- | --- |
| Spectral type | B8V |
| Surface temperature | 11 949 K |
| Luminosity (bolometric) | 290.6443 L☉ |
| Radius | 3.776 R☉ |
| Mass | 3.684 M☉ |
| Surface gravity (log g) | 3.728 |

### 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.

| Field | Value |
| --- | --- |
| Colour index (B−V) | −0.078 |
| Variable magnitude, brightest | 5.70 |
| Variable magnitude, faintest | 5.95 |

### 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.

| Field | Value |
| --- | --- |
| Proper motion (RA) | −11.23 mas/yr |
| Proper motion (Dec) | −32.04 mas/yr |
| Radial velocity | 5 km/s |

### OTHER NAMES AND NUMBERS

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

| Field | Value |
| --- | --- |
| Washington Double Star id | 07229+5517 |

### WHERE THESE FIGURES CAME FROM

Which catalogue, paper or model each of the fields above was read from, where the source named one.

| Field | Value |
| --- | --- |
| Spectral type from | SIMBAD (1969AJ.....74.1082M, quality D) |
| Stellar parameters from | Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: above 7,500 K GSP-Phot's temperature and extinction are degenerate |

## Also known as

- HD: HD 57103
- HIP: HIP 35785
- HR: HR 2784

## Source

[HYG Database v4.1](https://github.com/astronexus/HYG-Database) — CC-BY-SA-4.0

The producer asks: HYG Database v4.1, Astronexus (github.com/astronexus/HYG-Database). Fields derived from it stay under CC BY-SA 4.0.

How this was made: https://spacecatalog.org/methods#source-hyg

## Cite this page

SpaceCatalog. 19 Lyn A \[catalogue entry\]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-57103

```bibtex
@misc{spacecatalog_hd-57103,
  author       = {{SpaceCatalog}},
  title        = {{19 Lyn A}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/hd-57103},
  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from HYG Database v4.1.}
}
```

HYG Database v4.1 — CC-BY-SA-4.0

Acknowledgement the producer asks for: HYG Database v4.1, Astronexus (github.com/astronexus/HYG-Database). Fields derived from it stay under CC BY-SA 4.0.

The page itself, with its pictures, the sky map and the observing tools: https://spacecatalog.org/object/hd-57103