IC 2497 is a spiral galaxy located about 650 million light-years distant in the small northern constellation of Leo Minor. Although similar in size to the Milky Way galaxy it appears very small and faint due to its vast distance from us. At apparent magnitude +15.8, the galaxy is beyond the reach of most amateur backyard scopes and seemingly just one of the many thousands of faint galaxies populating the night sky. However a few years ago IC 2497 made international news not because of the galaxy itself but due to a new strangle object that was discovered next to it - Hanny's Voorwerp.

Hanny's Voorwerp

In 2007, Dutch school teacher Hanny van Arkel signed up to the newly created on-line citizen science project Galaxy Zoo. The project enlisted help from the public to classify vast numbers of galaxies based on their physical appearance. The original dataset used was obtained from the Sloan Digital Sky Survey and contained almost 1 million galaxies. With so many galaxies it was thought that the analysis would take years but the organisers were in for a pleasant surprise - within 24 hours the website was receiving almost 70,000 classifications an hour and the site even crashing temporarily due to the intense traffic.

Hanny van Arkel (credit:- Henny van Arkel)

Within a few days of signing up Hanny van Arkel while classifying galaxy IC 2497 noticed a blue object just below the galaxy. She asked if anyone knew what it was, and nobody did! The new object became known as "Hanny's Voorwerp" - Voorwerp the Dutch word for object. It turns out to be a giant gas cloud located next to IC 2497 that's as large as the Milky Way and believed to have been illuminated 100,000 years or so ago by a powerful quasar event at the centre of the galaxy. From recent X-ray and light measurements it appears that the quasar has at sometime within the last 70,000 years either "turned off" or even switched energy states and therefore no longer operating as it was. Whatever has happened, Hanny's Voorwerp and IC 2497 are incredibly interesting objects for professional astronomers.

Hubble telescope image of IC 2497 and Hanny's Voorwerp. (NASA, ESA, Keel Univ. Alabama/ Galaxy Zoo Team)

Location and observing

IC 2497 is located in the western section of Leo Minor and close to the Lynx border. It's positioned 4 degrees directly east of α Lyn (mag. +3.1) and 0.5 degrees southwest of star 13 LMi (mag. +6.1). To spot it at least a 350mm (14-inch) aperture scope is recommended. In total, the galaxy spans just 0.6 x 0.3 arc minutes of apparent size and even with the largest amateur scopes IC 2497 appears small, faint and lacking in detail.

If you think the galaxy is faint, the Voorwerp pushes this to another level. At about magnitude +19, it's incredibly dim! However, a few amateur astronomers with massive Dobsonian reflectors have managed to glimpse it as a ghostly glow hanging off the galaxy. It has been seen with scopes as small as 750mm (30-inch) in aperture!!

Finder Chart for IC 2497

Finder Chart for IC 2497 - pdf format

IC 2497 Data Table

IC2497
Object TypeSpiral Galaxy
ConstellationLeo Minor
Distance (ly)650,000,000
Apparent Mag.15.8
RA (J2000)09h 41m 04s
DEC (J2000)34d 43m 59s
Apparent Size (arc mins)0.6 x 0.3
Radius (light-years)57,500
Number of Stars400 Billion
Notable FeatureHanny's Voorwerp

Sky Highlights - July 2017

The Planets
This Month's Guide

Algol Minima
Algol eclipse dates and times for July

Meteor Shower
Southern Delta Aquariids (Aquarids) meteor shower peaks on July 29

Northern Hemisphere
Evening
West:- Mercury (mag. -0.5 to +0.3) (second half of month)
Southwest:- Jupiter (mag. -2.0)
South:- Saturn (mag. +0.2)
Midnight
West:- Jupiter
South:- Saturn
East:- Neptune (mag. +7.8)
Morning
Southwest:- Saturn
South:- Neptune
Southeast:- Uranus (mag. +5.8)
East:- Venus (mag. -4.1)

Southern Hemisphere
Evening
West:- Mercury (second half of month)
Northwest:- Jupiter
East:- Saturn
Midnight
West:- Jupiter
North:- Saturn
East:- Neptune
Morning
West:- Saturn
North:- Neptune
Northeast:- Venus, Uranus

Deep Sky

Small telescopes:-
Messier 13 - M13 - Great Hercules Globular Cluster
Messier 92 - M92 - Globular Cluster
Messier 11 - M11 - The Wild Duck Cluster (Open Cluster)
Messier 7 - M7 - The Ptolemy Cluster (Open Cluster)
Messier 6 - M6 - The Butterfly Cluster (Open Cluster)
Messier 4 - M4 - Globular Cluster
Messier 8 - M8 - Lagoon Nebula (Emission Nebula)
Messier 16 - M16 - Eagle Nebula (Emission Nebula with Open Cluster)
Messier 20 - M20 - Trifid Nebula (Emission and Reflection Nebula)

Shop at Amazon US

Contributions

If you like the website and want to contribute to the running costs then please do so below. All contributions are most welcome.

PayPal - The safer, easier way to pay online.