DR 28 – A Rare Planetary Nebula Candidate in Andromeda

Image Title: DR 28

Copyright: Jonathan Talbot

Date image was taken: November 25, 2024

Location: Stark Bayou Observatory Ocean Springs, MS

Data Acquisition Method: Personal Telescope Setup

Description and Details: DR 28 is a planetary nebula candidate in the constellation Andromeda. It was discovered by amateur astronomer Marcel Drechsler in May 2019. The central ionizing star is listed in Simbad as a white dwarf candidate. It goes by the designation Gaia DR3 450596357738685952. Its quite faint at magnitude 18.44 (G).

In an email I received from long time planetary nebula expert Dr Howard Bond, Penn State, he shared that a spectrum has been taken on this star and its been designated by Professor Klaus Werner (University of Tübingen, Germany) as a DAO white dwarf. A DAO white dwarf is a white dwarf with a presence of both hydrogen and helium in its spectrum. According to Dr. Bond, "DA means a white dwarf with hydrogen lines. The O is added when there is also helium; it comes from the O in the sequence OBAFGKM that is used for normal stars, indicating a very high temperature. So the star is a very hot one, at the beginning of the white-dwarf cooling sequence. As it cools down, the helium will settle out of the outer layers and it will become a pure hydrogen DA white dwarf."

With enough exposure time, DR 28 is quite photogenic showing a central area of [OIII] surrounded by H𝛼 which is oriented in a NE-SW direction. The brighter part of the object is roughly 8.5x5.5 arc min in size although fainter emission is spread out in an area around 24.5x21.9 arc min in size.

Throughout the field there is also faint H𝛼 emission and quite a bit of molecular dust.

There is only one other amateur image that I know of taken by Josep Drudis which can be found here: https://astrodrudis.com/dr-28-a-planetary-nebula-candidate/

The image was taken from 13 Oct 24 - 25 Nov 24 with my Stellarvue 6" refractor @zwoasi 6200 MM pro camera using Chroma RGB and 5nm [OIII] filters along with a Astrodon 5nm H𝛼 filter.. The image is comprised of 62hrs 20min of exposure time.

Name: Jonathan Talbot

Website or Facebook Profile: http://www.starscapeimaging.com