---
title: "James Webb Telescope Reveals Exoplanet WASP-17b Has an Egg-Like Shape"
description: "James Webb Telescope data has shown that the hot Jupiter WASP-17b, located 1,000 light-years from Earth, has a slightly elongated, egg-like shape. Astronomers estimated the deformation based on changes in stellar brightness during transit."
date: 2026-10-18T11:23:06.236Z
lang: en
url: https://xab.info/en/posts/exoplanet-wasp-17b-egg-shape
tags: [exoplanet, james-webb-space-telescope, hot-jupiter, wasp-17b, astrophysics]
author: "Alexander Buran"
publisher: "XAB.info"
---

# James Webb Telescope Reveals Exoplanet WASP-17b Has an Egg-Like Shape

![Illustration of the egg-shaped exoplanet WASP-17b against a starry background](https://xab.info/media/2026/10/18/ekzoplaneta-wasp-17b-forma-iaica/ekzoplaneta-wasp-17b-forma-iaica-1.webp)

## Key Points

- WASP-17b, located about 1,000 light-years from Earth, has a slightly elongated, egg-like shape.
- The deformation was assessed by measuring changes in stellar brightness during transit using James Webb data.
- The shape aligns with tidal models, though transit data cannot separate individual contributing factors.

Astronomers analyzing data from the James Webb Space Telescope have concluded that the exoplanet WASP-17b, located approximately 1,000 light-years from Earth, is not perfectly spherical: its shape is slightly elongated and resembles an egg. The planet belongs to the class of hot Jupiters—gas giants orbiting at a very short distance from their star. Under such conditions, powerful tidal forces can significantly deform the planet's body, and researchers estimate this is reflected in the recorded shape.

### How the Shape Was Measured via Transit

The method for assessing the shape is based on observing a transit—the passage of a planet in front of its parent star's disk. Scientists tracked how the star's brightness changed throughout the entire transit, and from this data calculated the distance from the planet's center to its edge in various directions. Comparing these values revealed a systematic deviation of WASP-17b from an ideal spherical shape, characterizing it as elongated.

### Tidal Forces and Theoretical Models

The recorded deformation is consistent with theoretical models of gas giants experiencing strong tidal forces. Several factors may simultaneously influence the planet's shape: proximity to the star, tidal synchronization of its rotation, and internal atmospheric circulation. At the same time, the authors emphasize that transit observations alone cannot unambiguously separate the contribution of each of these mechanisms to the final shape.

### Significance for Astrophysics

The result demonstrates that James Webb data allows scientists to study not only exoplanet atmospheres, but also their global shape. This approach opens up opportunities to more accurately test models of gas giant structure and determine how proximity to a star affects their physical properties. Further work will require comparing transit measurements with other observational methods to separate tidal and atmospheric effects.

## Fact-Check & Sources

- [Телескоп «Джеймс Уэбб» показал, что экзопланета WASP-17b имеет форму яйца](https://www.ixbt.com/news/2026/10/17/teleskop-dzeims-uebb-pokazal-cto-ekzoplaneta-wasp-17b-imeet-formu-iaica.html) - The primary source contains all key facts: ~1,000 light-years distance, hot Jupiter class, transit method, tidal forces, interpretation limits.

## FAQ

### What shape is the exoplanet WASP-17b?

According to James Webb data, the planet is slightly elongated and resembles an egg, deviating from a perfect sphere.

### How did astronomers measure the planet's shape?

They tracked the change in the parent star's brightness during a transit and used it to estimate the distance from the planet's center to its edge in various directions.

### Why is the planet deformed?

WASP-17b is a hot Jupiter orbiting close to its star, subjecting it to powerful tidal forces capable of deforming its body.