2023 March 18
Observer’s Challenge – Mini Messier Marathon – Open Clusters
March New Moon is the traditional time for the Messier Marathon challenge – to observe all the Messier objects in one night. This year 2023, New Moon will occur on Tuesday, March 21, 2023. This date suggests a primary weekend on March 18/19, and a secondary one on the weekend of March 25/26.
Of course there are many practical problems with a full Messier Marathon – not least that not all the Messier objects are visible from the UK, and as you head north in the country many become un-observable.
And as there are 110 objects in the Messier catalogue, it is also quite hard to get round them all. One of the best internet resources to help with a full Messier Marathon are these pages provided by SEDS.
For this ‘mini-marathon’ we’re just going to look for Messier’s open clusters – these should be easier to find and observe, and with more time available a chance for imagers or those using electronically assisted viewing to capture them too. There is still the big challenge of the objects with a southerly declination, so those objects in Scorpius and Sagittarius will be particularly difficult – even those in the south of the UK will still need a good southern horizon.
The list below of the 27 Messier open clusters is organised in a search order recommended by Don Machholz, whose book The Messier Marathon Observer’s Guide is excellent for anyone taking up the pursuit.
We will need a good clear night from dusk to dawn, though it might be possible to have a snooze or break half way through.
If you manage to observe or image these objects in one night, or even if you just manage a few – please post your observing report or images on your Members Page.
Good luck, happy Messier hunting!
|No.||Messier||Constellation||RA||Dec||Visual Mag.||Size (arc-min)|
|1||M52||Cas||23 24.2||+61 35||7.3||13|
|2||M103||Cas||01 33.2||+60 42||7.4||6|
|3||M34||Per||02 42.0||+42 47||5.5||35|
|4||M45||Tau||03 47.0||+24 07||1.6||110|
|5||M35||Gem||06 08.9||+24 20||5.3||28|
|6||M37||Aur||05 52.4||+32 33||6.2||24|
|7||M36||Aur||05 36.1||+34 08||6.3||12|
|8||M38||Aur||05 28.4||+35 50||7.4||21|
|9||M41||CMa||06 46.0||-20 44||4.6||38|
|10||M93||Pup||07 44.6||-23 52||6||22|
|11||M47||Pup||07 36.6||-14 30||5.2||30|
|12||M46||Pup||07 41.8||-14 49||6||27|
|13||M50||Mon||07 03.2||-08 20||6.3||16|
|14||M48||Hya||08 13.8||-05 48||5.5||54|
|15||M44||Cnc||08 40.1||+19 59||3.7||95|
|16||M67||Cnc||08 50.4||+11 49||6.1||30|
|17||M29||Cyg||20 23.9||+38 32||7.1||7|
|18||M39||Cyg||21 32.2||+48 26||4.6||32|
|19||M6||Sco||17 40.1||-32 13||5.3||25|
|20||M7||Sco||17 53.9||-34 49||4.1||80|
|21||M11||Sct||18 51.1||-06 16||6.3||14|
|22||M26||Sct||18 45.2||-09 24||8||15|
|23||M16||Ser||18 18.8||-13 47||6.4||7|
|24||M18||Sgr||18 19.9||-17 08||7.5||9|
|25||M25||Sgr||18 31.6||-19 15||6.5||40|
|26||M23||Sgr||17 56.8||-19 01||6.9||27|
|27||M21||Sgr||18 04.6||-22 30||6.5||13|
Best of Luck. Any results are welcome within the Member Galleries, sent to the Deep Sky Section or on the Forum.
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