IC1805 and IC1848 - The Heart and Soul Nebulae

Located in the Perseus Arm of the Galaxy, the Heart nebula (right) and the Soul nebula (left) are two bright nebulae (although a telescope is needed to see them) in a region of the Galaxy where a lot of stars are forming. IC 1805 (the Heart nebula) is also sometimes called the 'Running Dog nebula' because it is said to resemble a running dog when viewed through a telescope.

The Heart and Soul Nebulae
The Heart and Soul Nebulae. Image size: 5.3x4.3. DSS image. © CalTech/Palomar

The Nebulae associated with the Heart and Soul Nebulae

Below is a list of the main nebulae in this region. IC 1805 and IC 1848 are the two most important of these nebulae. IC 1795 is a bright nebula attached to the right side of IC 1805. NGC 896 simply seems to refer to the brightest part of IC 1795. IC 1871 is a minor nebula slightly detached from the left side of IC 1848.

   1              2              3          4     5       6      7        8
Catalogue    Equatorial      Galactic     Size   Type Distance Size  Other Names
Number       Coordinates    Coordinates (arcmins)       (ly)   (ly)
            RA (2000) Dec     l     b
--------------------------------------------------------------------------------------
NGC 896    02 25.5  +62 01  133.7   +1.1     5'   E     6150      9
IC 1795    02 25.8  +61 59  133.8   +1.1    30'   E     6150     55  
IC 1805    02 32.8  +61 27  134.7   +0.9   100'   E     6150    180  Heart Nebula
IC 1848    02 51.4  +60 25  137.2   +0.9   105'   E     6550    200  Soul Nebula
IC 1871    03 06.3  +60 40  138.7   +2.0    10'   E     6550     19
Column 1: The standard catalogue name for the nebula.
Column 2: Right Ascension and Declination for epoch 2000.
Column 3: Galactic Longitude (l) and Latitude (b).
Column 4: Angular size of the nebula in arcminutes.
Column 5: Nebula type: E = emission, R = reflection.
Column 6: Approximate distance to the nebula.
Column 7: Approximate size of the nebula in light years.
Column 8: Alternative name of the nebula.

Star clusters associated with the Heart and Soul Nebulae

There are seven star clusters which are known to be in the region of the Heart and Soul nebulae. Two of these star clusters (IC 1805 and IC 1848) are intimately connected with the nebulae and have the same catalogue numbers. Also in this part of the sky are the famous 'Sword Handle' clusters (h and Chi Persei) in Perseus - two of the brightest star clusters in the sky.

   1                2              3          4        5       6          7
Catalogue      Equatorial      Galactic     Size   Distance   Age    Other Names
Name           Coordinates    Coordinates (arcmins)  (ly)  (million
              RA (2000) Dec     l    b                     years)
-------------------------------------------------------------------------------
Basel 10     02 18.9  +58 19  134.2  -2.6     2'     6350      40
NGC 869      02 19.0  +57 08  134.6  -3.8    18'     6800      12    h Persei
NGC 884      02 22.4  +57 08  135.1  -3.6    18'     7650      11    Chi Persei
IC 1805      02 32.8  +61 27  134.7  +0.9    20'     6150       7
NGC 957      02 33.4  +57 34  136.3  -2.7    10'     5900      11
Berkeley 65  02 39.0  +60 25  135.8  +0.3     5'     7400      10
IC 1848      02 51.2  +60 26  137.2  +0.9    18'     6550       7
Column 1: The standard catalogue name for the cluster.
Column 2: Right Ascension and Declination for epoch 2000.
Column 3: Galactic Longitude (l) and Latitude (b).
Column 4: Angular size of the cluster in arcminutes.
Column 5: Distance to the cluster.
Column 6: Approximate age of the cluster in millions of years.
Column 7: Alternative name of the cluster.

References: Dias W, Alessi B, Moitinho A, Lpine J, (2002). New catalogue of optically
            visible open clusters and candidates. Astron and Astrophys, 389, 871.

A Map of the Heart and Soul Nebulae

Below is a map of the star clusters and nebulae in this region. Also labelled on this map are the two Maffei galaxies (Maffei I and Maffei II). When these very obscured galaxies were first discovered they were assumed to be nebulae and were even catalogued as nebulae (Sharpless 191 and Sharpless 197). It was only later that it was realised that they were galaxies 15 million light years behind the Heart and Soul nebulae.

A map of the Heart and Soul nebulae

The location of the Heart and Soul Nebulae

The location of the Heart and Soul nebulae The distance to these two nebulae are well determined, mainly because they have star clusters at the centre of them. (It is much easier to determine the distance to a nebula if it has star clusters in it). The Heart and Soul nebulae are located in the Perseus Arm of the Galaxy 6000 and 6500 light years away. This part of the Perseus Arm has a lot of star formation regions and there are many young star clusters in this region.

Right - a close-up view of IC 1795 which is part of the IC 1805 region. The very brightest part of this nebula is separately classified as NGC 896, because it was the first part of this nebula to be discovered. IC 1795
IC 1795. Image size: 0.5x0.5. DSS image.

Below - the pair of star clusters known as 'h Persei' (NGC 869 - right) and 'Chi Persei' (NGC 884 - left). This pair of clusters is also known as the 'Sword Handle' clusters (because of their location in the constellation of Perseus). These two clusters lie near to the Heart and Soul nebulae although they probably did not form in the nebulae (Chi Persei seems to be 1000 light years behind the nebulae, although h Persei is closer).

h and Chi Persei
h and Chi Persei. Image size: 1.0x0.8. DSS image.
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