Archive for February 2021

Herschel 400 Notes: By “Guest Host Sue French” From New York

February 16, 2021

Sue and Alan French

Click on to enlarge: The latest Herschel 400 book (above) from the Astronomical League. Consider ordering your copy today.

NGC 1893 Open Cluster + IC 410 Emission Nebula – February 2021 Observer’s Challenge Report – Auriga #145

February 5, 2021

MONTHLY OBSERVER’S CHALLENGE

Compiled by:

Roger Ivester, North Carolina

&

Sue French, New York

February 2021

Report #145

IC 1893 and IC 410, Cluster and Emission Nebula in Auriga

Sharing Observations and Bringing Amateur Astronomers Together

Introduction

This month’s target

John Herschel discovered the open cluster IC 1893 in 1827 with the 18¼-inch reflector at Slough in Buckinghamshire, England. His handwritten journal reads: “Rich, coarse, scattered and straggling. It more than fills the field. The stars are 9…15 magnitude.”  The engulfing nebula, IC 410, wasn’t discovered until 1892, when Max Wolf found some new extended nebulae on photographic plates taken with a 6-inch Voigtländer portrait lens. My paraphrased translation of the pertinent section of his discovery says: The ribbon-rich nebula shown on the plates around the star cluster surrounds the star BD+33 1023 [HD 242908] should also be new. It largely encloses the whole group.

The nebula is roughly 11,000 to 12,000 light-years distant, and the adolescent cluster within it is at least 4-million years old.

Complete Report: February 2021 OBSERVERS CHALLENGE _NGC 1893 and IC 410