---
title: "V4390 Sgr"
url: "https://spacecatalog.org/object/hd-168701"
release: "DR1"
licence: "CC-BY-SA-4.0"
citation: "SpaceCatalog. V4390 Sgr [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-168701"
---

# V4390 Sgr

V4390 Sgr is a K3II++B3/5? orange bright giant in the constellation [Sagittarius](https://spacecatalog.org/constellation/sagittarius), 2398 ly from Earth, shining at apparent magnitude 7.64 (V). Other catalogues list it as HD 168701 and HIP 90001.

## At a glance

- **WHAT IT IS:** Orange bright giant
- **HOW FAR:** 2398 ly — The light arriving now left it that long ago.
- **HOW BRIGHT (V):** 7.64 — Binoculars reach it; the naked eye does not.
- **WHERE TO LOOK:** [Sagittarius](https://spacecatalog.org/constellation/sagittarius) — The patch of sky it sits in, as seen from Earth.

## Properties

| Quantity | Value |
| --- | --- |
| CLASS | K3II++B3/5? orange bright giant |
| DISTANCE FROM EARTH | 2398 ly — by parallax |
| APPARENT MAGNITUDE (V) | 7.64 |
| ABSOLUTE MAGNITUDE (V) | −1.69 |
| CONSTELLATION | Sagittarius |
| RIGHT ASCENSION (J2000) | 18h 21m 48.9s |
| DECLINATION (J2000) | −16° 19′ 28.5″ |

## 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 | K3II++B3/5? |
| Surface temperature | 5897 K |
| Luminosity (visual) | 413.809 L☉ |
| Radius | 88.448 R☉ |
| Surface gravity (log g) | 1.407 |
| Variability | Beta Lyrae-type eclipsing binary |
| Variability type (GCVS) | EB |

### 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) | 1.116 |
| Variable magnitude, brightest | 7.60 |
| Variable magnitude, faintest | 7.73 |

### 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) | 2.09 mas/yr |
| Proper motion (Dec) | −2.22 mas/yr |
| Radial velocity | 21.8 km/s |

### OTHER NAMES AND NUMBERS

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

| Field | Value |
| --- | --- |
| Variable-star designation | V4390 Sgr |
| Washington Double Star id | 18218-1619 |

### 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 (2002ApJS..143..513G, quality C) |
| Stellar parameters from | Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) |

## Also known as

- HD: HD 168701
- HIP: HIP 90001
- Variable star: V4390 Sgr

## 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. V4390 Sgr \[catalogue entry\]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-168701

```bibtex
@misc{spacecatalog_hd-168701,
  author       = {{SpaceCatalog}},
  title        = {{V4390 Sgr}},
  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},
  year         = {2026},
  url          = {https://spacecatalog.org/object/hd-168701},
  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-168701