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Cosmic Challenge: M1, the Crab Nebula
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Cosmic
Challenge:
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This month's suggested aperture range: |
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7x to 10x Binoculars |
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Target |
Type |
RA |
DEC |
Constellation |
Mag |
Size |
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M1 |
Supernova remnant |
05h 34.5m |
+22° 01.0’ |
Taurus |
8.4 |
6'x4' |
The universe changed on August 28, 1758. Early that morning, as he scanned the predawn sky for Halley's Comet on its predicted return, the French comet hunter Charles Messier found something he had never seen before through his telescope. The mysterious object, lying just off the southern "horn" of Taurus, the Bull, looked just like a comet through his small refractor. Returning over the course of the next two weeks, Messier realized that what he had found could not be a comet, since there was no telltale indication of orbital motion. Instead, it remained anchored in place. Messier noted the position of his unexpected discovery, and was later to include it as the first entry in a catalog of annoyances that might fool him and his fellow comet hunters into thinking they too had found a new comet. The rest, as they say, is history. (To be correct, Messier was not the first person to see M1. That distinction belongs to London physician and amateur astronomer John Bevis, who discovered it 27 years earlier.)
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Above: Evening star map. Credit: Map adapted from Star Watch by Phil Harrington |
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Above: Finder chart for
this month's Cosmic Challenge.
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The story of M1, of how it is the expanding remnant of a massive star that detonated in a huge supernova explosion, is well known to most. That explosion was witnessed by ancient Chinese and Anasazi Native American stargazers in July 1054 AD. Although half a world away from each other, both recorded the exploding star's sudden appearance. At its peak, the supernova may have shone as brightly as magnitude -6 and was visible in broad daylight for nearly a month.
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Above: Anasazi supernova petrograph showing the 1054 supernova. Source: Alex Marentes, CC BY-SA 2.0, via Wikimedia Commons |
Today, when we look toward the site of the supernova explosion, all we see is the expanding cloud of debris that we call the Crab Nebula. The nebula got its nickname in 1844 when British astronomer William Parsons, the Third Earl of Rosse, observed it through his telescope and sketched its appearance. He noted that its intricate, filamentary structure resembled the legs and body of a crab. Although modern observations reveal a far more complex and dynamic structure, the name "Crab Nebula" has persisted, serving as a historical nod to Parsons' interpretation of its appearance during the early days of astronomical study.
The nebula’s elaborate structure seen in photographs consists of expanding filaments of ionized gas, primarily hydrogen, helium, and heavier elements like oxygen and carbon, traveling at 1,500 km/second. Its synchrotron radiation, generated by high-energy electrons spiraling in magnetic fields, makes the Crab Nebula a strong emitter across the radio to gamma-ray spectrum. At its core lies the Crab Pulsar, a rapidly spinning neutron star emitting powerful beams of radiation.
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Above: M1 as taken by CN'er David Raphael in Lakeway, TX, using a GSO 12" f/8 Ritchey-Chrétien. Details can be found on his Astrobin posting. |
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Above: M1 is shown here at a similar scale as seen through binoculars. Photo taken by the author using a Dwarf 3 astrograph (50 minute total integration, dual-band filter in place). |
On a personal level, the universe changed for me in January 1972, and M1 was the reason. It was a cold winter night, with snow on the ground and crystal clear skies overhead. Outside in my backyard, I had my new 8-inch reflector, my trusty Skalnate Pleso Atlas of the Heavens, and a pair of 7x35 binoculars. Wearing a heavy parka to insulate me from the cold, I laid back against a pile of snow, enjoying the sky with the binoculars as I waited for my telescope's optics to acclimate to the cold temperature. As I made my way past many winter favorites, I happened to scan along the southern horn of Taurus. Third-magnitude Zeta (ζ) Tauri marks the tip of the horn.
Through the binoculars, I could also see nearby 6th- and 7th-magnitude stars that, with Zeta, formed a small trapezoid that I had used in the past to find M1 through my reflector. Looking more closely at the field, I thought I could see the dimmest smudge of light nearby. Sure enough, I was seeing, ever so faintly, M1 through the binoculars. That one observation convinced me about the potential of binoculars and began my lifelong pursuit of pushing them to their limits, which I enjoy doing to this day.
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Above: M1 as seen through the author's 10x50 binoculars.
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With 10x and lower-power binoculars, M1 looks like a rounded rectangle of grayish light (as illustrated above). That's an unusual shape in a universe of round and oval nebulae. Like many smaller deep-sky objects, M1 benefits from magnification and smaller exit pupils. Under dark skies, it appears much more obvious through a pair of quality 16x50 binoculars than through similar 10x50s, and even more so than through 7x50 binoculars. The secret to seeing it is to brace the binoculars against something, whether that something is a tripod, a fence post, or, yes, even lying in a pile of snow.
Good luck with this month's Cosmic Challenge! And be sure to post your results in this column's discussion forum.
Until next month, remember that half of the fun is the thrill of the chase. Game on!
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About
the Author: |
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Phil Harrington's Cosmic Challenge is copyright 2025 by Philip S. Harrington. All rights reserved. No reproduction, in whole or in part, beyond single copies for use by an individual, is permitted without written permission of the copyright holder. |
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- Ramon Miro, John O'Hara, warddl and 2 others like this
18 Comments
M1 is a nice little object, but not straightforward to see in binoculars. It caused me much confusion and frustration, when I first started out observing and only had an old 10x50 with only partial coatings. M1 was nowhere to be found.
It wasn't until I got my first real telescope, a 60mm Vixen, in 1992, that I saw M1 unmistakably. Ever since, I've seen it every year. It's still not easy to see in my 10x50 (a Zeiss Oberkochen, far superior to my old Japanese one), but in my 16x70, it's quite easy.
It's easy and straightforward to see in my little 63mm Zeiss, if the night is clear and moonless. It has a vague Z-shape and looks a bit like a faint candlelight. A 6" starts to show some mottling and variations in light in the little nebula.
In my 12" Dob on the best nights, using magnifications in the 200x range, I can begin to glimpse filaments.
M1 observed February 3rd, 2011. Zeiss Telemator, 63/840mm, 25mm TS Kellner + 2x barlow, 67x, and 10mm TS Kellner, 84x. Strong wind, drifting clouds, haze, bad seeing, some light pollution... Not very good conditions. NELM around 5, M35 barely visible naked eye. Sketch mostly done while waiting for sucker holes. Observed from around 8.15 PM to 8.45 PM.
M1 Crab Nebula, December 20th, 2024. Zeiss C63/840 on Zeiss 1b mount, 40mm GSO projection eyepiece, 21x, 2° TFOV. 8 x 30 seconds at 6400 ISO. OnePlus Nord CE3 Lite, Deep Sky Camera app. Stacked in DSS, processed in Windows Pictures.
Clear skies!
Thomas, Denmark
No winter imaging season is complete without spending a little time on this DSO. This is my image from November 2024.
Tech Specs: Orion 8” RC Telescope, ZWO ASI2600MC camera running at -10F, 4 Hours and 7 Minutes using 60 second exposures, Celestron CGEM-DX pier mounted, ZWO EAF and ASIAir Pro, processed in PixInsight. Image Date: November 2, 2024. Location: The Dark Side Observatory (W59), Weatherly, PA, USA (Bortle Class 4).
Thanks for a nice write up Phil. M1 in bino is definitely quite a challenge, at least for me. I have been trying to spot M1 through my new 7x21 all the late autumn and the beginning of this winter. So far no luck under our light polluted backyard (about ~5 mag sky).
Observing the sky with small bino is a wonderful experience. We were out to see the New Year's fireworks and just before the midnight I was looking for some familiar targets with 7x21 (M31, M33, M34-M37, M42, M45, ...). I was also scanning the area around Sirius and Monoceros. I run on six open clusters, some of them I was able to identify later on at home by consulting my memory with atlas (M41, M46, M50, open cluster in Rosetta). The remaining two of them were probably some other larger NGC open clusters. This was definitely a fun.
Another negative try... This time I was really carefully looking at the location and I was also trying to fix my hands as much as possible. In 7x21, the faintest star in the trapezoid was difficult to spot, it required some concentration. In 8x40, the trapezoid was obvious - there might have been some hints on something going on at the location of M1 but I could not convince myself it was real. For this critical observation, I went out to our terrace.
The rest of the observation was in warm room through large window. I confirmed with that one of the stellar patch that I observed in the night from 31.12.2024 to 1.1.2025 was indeed the open cluster in Rosetta. I could see in 7x21 three other stellar patches around this cluster. They were standing out quite well with averted vision. To my surprise, all the patches are plotted in the Pocket Sky Atlas as open clusters: Cr 97, 106, 111. I recently required original Collinder catalogue of open clusters from 1931 (Annals of the Observatory of Lund No. 2). This might be also a nice project - try to see as many of them through small binoculars.
Hi Sasa. I suspect 7x21s might be a little too small for M1. My first binocular sighting in the 1970s was with 7x35s, and then just barely. But be sure to try it again, maybe under darker skies. You might just spot it.
Spotting M1 in a 7x21 is certainly quite a challenge, even under very good conditions. I've managed it in my 8x40, and it was by no means easy. I have an 8x30 Zeiss with phenomenal optics, and I'm going to try that next.
Getting a good image with my smartphone through the Zeiss Meniscas 150 is also on my to-do list.
Clear skies!
Thomas, Denmark
I had another (negative) try. This time I was also concentrating on similarly bright stars. I was able barely to detect V=8.3 star in 7x21, nebulosity would be more difficult. The star was still difficult to spot in 8x40.
For us in urban areas, EAA is the only way to see it.
I remember seeing M1 in my 50mm F/4 Stellarvue finder scope from a dark sky years ago. The finder was designed for interchangeable eyepieces, so I used my Nagler T6 eyepieces.
I don't remember which Nagler I used to first see it, possibly the 9mm at 22x, or the 7mm at 28.6x, but I remember the Nagler 5mm T6 at 40x gave the best view.
My favourite observations of M1 occurred over the last week of 2002 and the first week of 2003 when Saturn passed directly in front of it. There was a 3 day period when the brightness of Saturn completely obliterated the view of M1.
Fun Times.
Bill
I saw M-1 from my urban backyard in a 60 mm Meade F/11. I wrote a review that Rod Mollise published in his Skywatcher Ezine and it was later republished in "Amateur Astronomy." "Fifty dollars at Walmart."
It was about 1:30 am on a particularly dark night and it was 20 years ago when my eyes were better.
But I still see M-1 from my urban backyard (mag 18.2-18.6 mpsas overhead) with telescopes. Larger is easier but I believe I've seen it recently in a 4 inch. The key is knowing the exact location. It's but a faint glow.
I calculate the average surface brightness at 20.5 mpsas so it should be doable from an urban sky.
I see it in my 10x50s from the high desert.
Jon
I had a dark window of about an hour between end of twilight and moonrise last night, so I gave this a try. Instead of binoculars I used the 3" f/4 Newtonian finder on my 10" f/4. The eyepieces are located close to each other with the same orientation of the field (minimizes mental gymnastics). After acquiring M1 in the 10" and noting its location relative to star patterns, I could hold M1 with averted vision at 18x and 25x in the 3". I decreased magnification to 13x and could not see M1, which isn't surprising since the exit pupil was larger than my aged eyes can accept fully.
During the 2024 Black Forest Star Party, I was able to accomplish something that I had never expected to do, that is, visually observing PSR B0531+21, the pulsar in M1, using a friend's 24" f/3.3 Starmaster Sky Tracker Dob and his TNVC night vision device at very high magnification.
An article on observing M1's pulsar can be seen at https://skyandtelesc...he-crab-pulsar/
I tried so hard to see the Crab Nebula the past few years from my city skies using a C5. Even with my UHC or O-III filter and 32mm Plössl, no dice. But it was a shockingly easy object once I traveled to Bortle 3 skies; immediately apparent with an 8" RC and 36mm Baader Hyperion (45x, 4.5 mm exit pupil). I don't think my C5 would have any trouble revealing it under those conditions. I did have access to my friend's Oberwerk 20x80s, but we never thought to turn it to the Crab.
That being said, now that I have a GoTo mount, I'm gonna try to rule out the possibility that I'm just really bad at pointing my telescope at it.
This is an object I first saw in the 1970s in my then new to me Tasco 60mm alt-az refractor. When I got my ETX-105 in 2001 and did my first Messier Marathon it was a revelationto see it from better skies with a better telescope. I imaged it for the 1st time around then, but can't find that crude attempt (thankfully).
I revisted the crab for the first time in 20+ years last December. Here's that image.
It doesn't begin to compare to Astronomy4You's excellent image but here's one of the Seestar S50 images of M1 that I captured at the orange zone Naylor Observatory.
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Very nice write up. Thanks for the detailed info. Here is a recent image of M1 I got with my Vespera Pro...