Advertisement / Annons:

Constellation
Great Bear, Seven Stars

Object :	Constellation Great Bear (Ursae Majoris) and its stars
Coordinates/Direction :	RA: 10h67m, DEC: +55^o38'
Object size :	10 x 30 degrees
Object magnitude :	-
More to know :	You can read more about the constellation Great Bear at Wikipedia: https://en.wikipedia.org/ wiki/ Ursa Major

Sometimes even astronomy can be boring. I need some inspiration to do something new. Outside the window I noticed the constellation Great Bear was in perfect position this night. When thinking abut Great Bear, okay it's a fine constellation but not more or ? Could it be more that are lurking out there in the deep space ? Let's find out, I will examine what's in the neighborhood of the seven bright star in the Big Dipper, part of Great bear constellation.

All images taken with Canon 6D full frame and a Pentax 300 mm lens. Field (FOV) : 6.8x4.5 degree, before cropping

Constellation Big Dipper, part of Great Bear:

Credit: CdC / Skychart

It's only the upper left seven stars that I investigate of this constellation, the tail of Great Bear or Big Dipper as some call it. In Sweden we call it "Stora Karlavagnen". It has seven stars and they build the figure Big Dipper on the night sky.

Comment :

The star I investigate and their surroundings:

Dubhe (Alpha Ursae Majoris),
Merak (Beta Ursae Majoris),
Megrez (Gamma Ursae Majoris),
Pheoda (Delta Ursae Majoris),
Alioth (Epsilon Ursae Majoris),
Mizar (Zeta Ursae Majoris),
Alkaid (Eta Ursae Majoris)

The star Mizar is the most famous of them because it's a double star.

Each chart below will be complemented with a photo that is centered around its star from the list above. I use a Canon full frame camera and a 300 mm lens. Each photo has a FOV (field of view) 7 x 5 degrees, for the stars that are close to each other the edges of the photos will overlap.

Dubhe (Alpha Ursae Majoris)

Coordinates/Direction :	RA: 11h03m, DEC: +61^o45'
Object size :	-
Object magnitude :	1.79
Object :	Dubhe (Alpha Ursae Majoris)
Comment :
More to know :	More information about the star at Wikipedia: https://en.wikipedia.org/ wiki/ Alpha Ursae Majoris

(Click on the image to get one in full resolution in a new window)

Comment :

The bright 1.79 magnitude star dominate the area in this photo, the star itself is a binary, it's found by spectroscope measurements. The period is 44.5 years. Click on the image and look at the weak objects in the background, which of them can you find ?

To find what the weaker objects are I have done a Plate Solving of the above image, it's done at Astrometry.net, you can upload your images here and it will be analyzed and the objects identified.

Comment :

The galaxy NGC 3359 in the upper right corner is bright and easy to see. It's called an emission line galaxy in SIMBAD. The NGC 3668 and NGC 3671 are Radio galaxies and NGC 3470 has an active Nucleus.

Objects :

Information about the objects I have found at SIMBAD Astronomical Database, click on them below and you will get a lot more information about them:

Merak (Beta Ursae Majoris)

Coordinates/Direction :	RA: 11h01m, DEC: +56^o22'
Object size :	-
Object magnitude :	2.37
Object :	Merak (Beta Ursae Majoris)
Comment :
More to know :	More information about the star at Wikipedia: https://en.wikipedia.org/ wiki/ Beta Ursae Majoris

(Click on the image to get one in full resolution in a new window)

Comment :

This together with Dubhe is what you use when aiming for the Polar star. The distance to it is 79.7 light years. Its mass is 2.7 times our Sun so it's a big star.

The plate solving found a lot of objects in this region. One of them is the Owl Nebula, M97. A small but beautiful planetary nebula, the remnant of a star explosion. You can also find M97 on the star chart above and get a felling of the scale. Not far away is the beautiful galaxy M108.

Comment :

The galaxy NGC 3683 is a HII galaxy, NGC 3517 have an active nucleus. NGC 3674, NGC 3613 and NGC 3530 belongs to a group of galaxies. NGC 3408 is a radio galaxy. M97 is a planetary nebula. 44 UMa is a high proper-motion star.

Objects :

Information about the objects I have found at SIMBAD Astronomical Database, click on them below and you will get a lot more information about them:

Megrez (Gamma Ursae Majoris)

Coordinates/Direction :	RA: 11h53m, DEC: +53^o41'
Object size :	-
Object magnitude :	2.44
Object :	Megrez (Gamma Ursae Majoris)
Comment :
More to know :	More information about the star at Wikipedia: https://en.wikipedia.org/ wiki/ Gamma Ursae Majoris

(Click on the image to get one in full resolution in a new window)

Comment :

An earlier name of Megrez was Phecda, I don't know why they changed the name of it. The satellite Hipparcos found the distance of the star to be 83.2 light years.

No object here that I know something about, the star chart above looked a bit empty but can now see that there are plenty of objects.

Comment :

70 UMa is a high proper motion star, NGC 4500 is a blue compact galaxy, NGC 3958, NGC 4172 and NGC 4161 have active nucleus

Objects :

Information about the objects I have found at SIMBAD Astronomical Database, click on them below and you will get a lot more information about them:

Pheoda (Delta Ursae Majoris)

Coordinates/Direction :	RA: 12h15m, DEC: +57^o01'
Object size :	-
Object magnitude :	3.31
Object :	Pheoda (Delta Ursae Majoris)
Comment :
More to know :	More information about the star at Wikipedia: https://en.wikipedia.org/ wiki/ Delta Ursae Majoris

(Click on the image to get one in full resolution in a new window)

Comment :

Pheoda is the dimmest of these sevens tars with its magnitude of 3.3. It's found that the distance is 80 light years and it's a bit more massive then our Sun at 1.63 solar masses. They have also found a debris disc around the star.

M 109 galaxy is something I know from earlier, this galaxy is big enough for me to catch on photo even with this small telescope.

Comment :

NGC 4194 and NGC 4102 has active nucleus, NGC 3846 is a radio galaxy. M109 belongs to a group of galaxies.

Objects :

Information about the objects I have found at SIMBAD Astronomical Database, click on them below and you will get a lot more information about them:

Alioth (Epsilon Ursae Majoris)

Coordinates/Direction :	RA: 12h54m, DEC: +55^o57'
Object size :	-
Object magnitude :	1.77
Object :	Alioth (Epsilon Ursae Majoris)
Comment :
More to know :	More information about the star at Wikipedia: https://en.wikipedia.org/ wiki/ Epsilon Ursae Majoris

(Click on the image to get one in full resolution in a new window)

Comment :

Alioth is really a bright star with its magnitude of 1.77. It's the 33 strongest star in the sky. This star has been used in celestial navigation, one of 57.

Big Dipper, Alioth (Epsilon Ursai Majoris)

No objects that I are aware of.

Comment :

NGC 4500 is a blue compact galaxy, NGC 4977 and IC 830 has an active nucleus, NGC 4566 is a Seyfert 2 galaxy.

Objects :

Information about the objects I have found at SIMBAD Astronomical Database, click on them below and you will get a lot more information about them:

Mizar (Zeta Ursae Majoris)

Coordinates/Direction :	RA: 13h23m, DEC: +54^o55'
Object size :	-
Object magnitude :	3.9
Object :	Mizar (Zeta Ursae Majoris)
Comment :
More to know :	More information about the star at Wikipedia: https://en.wikipedia.org/ wiki/ Mizar

(Click on the image to get one in full resolution in a new window)

Comment :

Mizar is a famous double star which is clearly seen at this photo, and more, each of these stars are also double stars. The only object here that I already know about. Can you resolve the two stars by the naked eye ?

My friend Björn has something to tell about this star:
"I contributed to a recording for SvT about satellite observations, and we filmed two NOSS that passed as a couple nearby. Afterwards the photographer showed me Mizar A and Mizar B zoomed, so we only saw these at the edges (14' distance!) AND the weaker star in between!", "My favorites i UMa are these two (with a third in the middle)":https://www.star-facts.com/mizar/

The star Mizar is the only object I know about.

Comment :

IC 942, NGC 5255, NGC 4977 and NGC 5201 has an active nucleus, NGC 5001 is a radio galaxy, 82 UMa is a high proper motion star.

Objects :

Information about the objects I have found at SIMBAD Astronomical Database, click on them below and you will get a lot more information about them:

Alkaid (Eta Ursae Majoris)

Coordinates/Direction :	RA: 13h47m, DEC: +49^o18'
Object size :	-
Object magnitude :	1.9
Object :	Alkaid (Eta Ursae Majoris)
Comment :
More to know :	More information about the star at Wikipedia: https://en.wikipedia.org/ wiki/ Eta Ursae Majoris

(Click on the image to get one in full resolution in a new window)

Comment :

Alkaid, the last of the seven stars. This star doesn't move together with the other of these seven stars. It's also a hot star and emit X-ray.

The star Alkaid I know from earlier. At the lower right corner is something really interesting, the Whirlpool Galaxy a famous galaxy with many names, Messier 51 or NGC 5194. In a bigger telescope there are a lot of interesting details and beautiful to look at. But as you see, even in my small telescope you can see it.

Comment :

IC 951 and NGC 5229 are low surface brightness galaxies. 13 Boo is a long period variable star. IC 907 is a Seyfert 2 galaxy, IC 902 is an emission line galaxy. NGC 5449 and NGC 5377 has active nucleus. 24 CVn is a high proper motion star. And at last, NGC 5194 is the famous M 51 Galaxy.

Objects :

Information about the objects I have found at SIMBAD Astronomical Database, click on them below and you will get a lot more information about them:

Used equipment and common information:

Date :	2022-01-14
Time (UT) :	-

Mount :

SkyWatcher HEQ5, belt modified, low rider

Guide :

QHY5 camera with 200 mm f/3.5 lens

Lens/telescope :	Pentax 645 300 mm ED f/4 (medium format lens)
Corrector/Barlow :	-
Field (FOV) :	6.8x4.5^o (full frame) before crop

camera :	Canon 6D, QE=0.5, full frame, 20 Mpixel, 14 bit
camera temperature:	About 6^o C above surrounding temperature
Film/CCD :	Raw, Cr2
Filter :	none

Control system:

Mount, camera, focus, guide (Ekos) controlled by Astroberry (KStars/Ekos Linux)

Exp. time :	30x30 seconds, iso1600, dithering mode
Image process tool :	Siril, Fitswork, IrfanView
Processing :	Calibrated with Bias, Darks and Flats. Stacked and stretched
Weather :	clear

Site :

Sweden, Stockholm, Hagsätra. Bortle 9
Free view Az: 20^o to 90^o, 165^o to 185^o, Alt: 20^o to 55^o

Comment :

This is my latest equipment, much smaller and lighter than the earlier. I hope it will weight in below 20 kg inclusive the battery when it's finished.

Go Back to content

Go Back

Constellation Great Bear, Seven Stars

Constellation Big Dipper, part of Great Bear:

Dubhe (Alpha Ursae Majoris)

Merak (Beta Ursae Majoris)

Megrez (Gamma Ursae Majoris)

Pheoda (Delta Ursae Majoris)

Alioth (Epsilon Ursae Majoris)

Mizar (Zeta Ursae Majoris)

Alkaid (Eta Ursae Majoris)

Used equipment and common information:

Constellation
Great Bear, Seven Stars