Last updated: 6 October 2001

A Gallant Hero and Rescuer of Fair Maidens

From: sherrodc@ipa.net (Clay Sherrod)

Perhaps one of the "top ten" most remembered and/or recognized constellations - PERSEUS - is our 29th Constellation Guide, "GO TO PERSEUS" of the series "GO TO GUIDES" for the modern GO TO computerized telescope. To almost all who see this familiar star pattern - just as it was thousands of years ago - it is nearly immediately visually "paired" with the conspicuous "W"-shaped asterism of Cassiopeia, the Queen to its west.

Likewise, it is hard to have studied either of them and not remember that - located midway between their brightest stars - the famous "Double Cluster" is positioned as perhaps the finest galactic cluster(s) visible to the naked eye and binoculars. Undoubtedly, there are those that would argue that the Pleiades (Messier 45 in Taurus and our second closest star cluster) rivals any such cluster due to its beautiful bright seven-to-nine naked eye stars. However...there is a silent mystery about the double cluster that you do not find with something so conspicuous as the Pleiades: it hints at so much you cannot see to the naked eye. It literally INVITES you to explore further, to use optical aid, to increase light gathering and magnification and hence probe deeper into its core and see fainter stars. The location of the Double Cluster amidst the generously thick groupings of distant stars of the Milky Way adds to the beauty of the star fields throughout this region.

The star chart below for your use in the "GO TO" TOUR shows the connecting "lines" of the brighter stars; however, since the 1970's (we all DO remember the 1970's do we not?) the star pattern appears to the naked eye to trace out a popular figure that originated in those ancient times known as "the Keep-on-Truckin' Man.", a happy little cartoon fellow walking rapidly to his left, arms outstretched and in full stride.

Even today, you will see the "Keep-on-Truckin' Man" cartoon character emblazoned on 18-wheeler mud flaps and on commercial truck decals throughout the United States and Australia.

Click for full-size version

The constellation of Perseus is located in a wonderful part of the sky for two reasons. First, as it rises higher and higher in the eastern sky beginning in late summer, it beckons dusty telescopes and the "night-allergic" among us outdoors as crisp, cool fall skies slowly replace the humidity- and mosquito-laden skies of summer. Second, this portion of our night skies - regardless of the season - is one of the most intriguing from the standpoint of such a wonderful array of deep sky objects and fantastic double/multiple stars.

Because of the positioning of our solar system in the Milky Way galaxy you will note that Perseus, much like its nearby neighboring constellations, is void of galaxies bright enough to be observed in common amateur telescopes; look for those in the spring and early summer skies....in the fall, we enter the realm of the GALACTIC CLUSTERS. Hence, as with the constellation of Auriga, I am adding as a bonus at the end of the Concise Listing of Perseus objects for this TOUR an abbreviated directory of all galactic clusters that can be viewed in small to large amateur telescopes.

Take the time to explore this wonderful area with the naked eye and with binoculars or a very low power, wide field telescope. From the chart above you note that Perseus is in an enviable position in the sky. To its west are the wonderful object-rich boundaries of Cassiopeia and Andromeda, to its east is the charioteer Auriga, also filled with wonderful galactic clusters and to its south is Taurus, the bull, with its two brightest and closest star clusters, the Hyades and the Pleiades.

Indeed, even scanning around the bright primary star of the constellation, Algenib, you will see clearly in binoculars that it, too, is associated with a very large and bright scattering of cluster stars as part of the Perseus Milky Way.....examine this area near Algenib on the darkest of nights with wide field telescopes and/or good 7 x 50 binoculars for a sight you will remember for the rest of your life.

From mid-northern latitudes Perseus just dips below the extreme northern horizon right at midnight on May 15 each year, the only time at midnight that all stars of the constellation are hidden from nighttime view. Conversely, midnight culmination of its brightest star, Mirfak, when the star is highest overhead at midnight always towards the end of the first week in November every year.

Within the borders of Perseus are 12 brighter galactic stars clusters that are of interest to amateur astronomers, all of which are visible in the widest range of telescope sizes, and certainly some even in binoculars. Only ONE of these clusters is designated as a Messier Object, although several others could just as easily be so assigned. I have always been amazed that the Double Cluster(s) was not so designated by Messier, and that these fantastic twin clusters remained unnamed throughout history except much later as an "NGC" object. That is very much like in horse races.....they apparently "Also Ran..."

In addition to these "fixed" celestial objects which grace Perseus, there is another celestial treat that we experience once each year from within its borders....the PERSEID METEOR SHOWER, which emanates only four degrees south of GAMMA PERSEI (more on this later!).

Perseus (pronounced EITHER "purr-SEE-us" OR "purr-SEUS", depending on your upbringing) is a mythological giant among tall tales. An explanation for the alternative second pronunciation follows.

MYTHOLOGICAL LORE #1 - The Conception and Eventful Life of Perseus as a Hero The mighty mythological kingdom of Argos (from which came Jason and his famed "Argonauts") was ruled by King Acrisius who had but one daughter, the most beautiful of all the kingdom. However, being warned by a soothsayer that his own grandson will kill him later in life, Acrisius decided to hide Danae away so that the possibilities of her having any children would be impossible. As legend has it, the high god ZEUS himself however, took a liking to the beauty of Danae that he could see through the chamber walls when no mortal man could. Well, one thing led to another and eventually Danae conceived a son by Zeus - PERSEUS (or "per-Zeus"...the latter pronunciation). Alarmed at the sudden realization that he NOW had a grandson, Acrisius sent both Danae and her son far away to Seriphos, a beautiful but isolated island ruled by the King Polydectes who - you guessed it - fell in love with Danae. To have his undivided attention from her, the king sent Perseus packing away on many death-defying and perilous missions. The most memorable (boy, does this sound like afternoon TV?) was to go out and return with the head of Medusa, the horrible snake-headed Gorgon who turned mighty men to stone by merely glancing at her horrible face and figure. He ultimately tricked Medusa by approaching her with his shield to his eyes so that he could not look and did, indeed, cut off her head! But, unlike daytime drama television, a winged HORSE (Pegasus) sprang from Medusa's headless body which was quickly mounted and tamed by Perseus to return him back to Seriphos. But.....on his way back, he hear the horrible screams that could only be coming from a woman tethered to a bunch of cragged rocks next to a sea shore, (probably a reference to Gibraltar of Cadiz, or if this tale is even older, it is likely a reference to the huge outcropping rocks overlooking the Red Sea from the coast of Israel) a woman who no doubt was about to be eaten alive by the dreaded sea monster Cetus (now a docile whale). Sure enough, he was RIGHT! He and Pegasus swooped down just in time to rescue the fair maiden ANDROMEDA and ultimately would become her princely husband.

So did he kill his grandfather? Yep...hit him in the head accidentally while practicing his celebrated discus throw for an upcoming sporting exhibition at a funeral, thus keeping the old soothsayer an honest man.


MYTHOLOGICAL LORE #2 - [short and "G-rated" version] - The Philandering Heroics of Perseus To keep it short, the part about the rescue of Andromeda who had been chained to the cragged rocks by the sea shore in wait of the horrible Cetus sea monster is the same. It is how Andromeda came to be chained there in the first place, and just what relationship Perseus ALREADY had with the family of Andromeda, notably her father KING CEPHEUS and mother QUEEN CASSIOPEIA who was suspected of being "romantically attracted" to the young and charming upstart PERSEUS.

Cassiopeia was an arrogant and vain woman, who acclaimed her beauty far better than that of the romantically-toxic sea nymphs, among them the Gorgon Medusa who ask King Neptune (or Poseidon) to punish the Queen for her excessive vanity and arrogance. Hence, Neptune summoned the great sea monster CETUS to ravage the kingdom of Cepheus an order that was quickly learned back home by Cepheus through his soothsayer sage. According the wise sage, the only way to prevent the fall of the kingdom would be for Cepheus to sacrifice his ONLY daughter, Andromeda, to the menacing monster; hence she was agreeably chained to a remote cragged bunch of rocks in await of the monster.

Because, apparently, from her attraction to Perseus and the fact that Perseus was "really" in love with Andromeda, not her mother, Cassiopeia had no objections to this decision (at least there is no mention of any pleas of compassion anywhere....).

Nonetheless, Perseus heard Andromeda's faint whimpers and swooped down just in time to reflect Medusa's ugly image, snakes and all, onto the awaiting eyes of Cetus who immediately turned to stone.

....and they all lived happily every after (except Cassiopeia, who was still stuck with Cepheus). I told you it was the abbreviated and G-rated version.


As with every "GO TO" TOUR guide, each GO TO object Perseus is discussed for your telescope regarding the type of conditions necessary for you to view it optimally for discern the very faintest details.........magnifications and aperture necessary for most objects, and much, much more. This is YOUR complete GUIDE to get you on your way to exploring the best (and few!) objects in these two constellations. The following listing of "BEST" objects contains the finest or most interesting from my own observing experience and preference.

Use the attached star chart and the following Guide as an excellent reference for your next star party itinerary, or a beginning for further study into the thousands of objects visible in this part of the sky. Truly these extensive Constellation Study Guides will most definitely put your AutoStar to work for you in the most efficient and enjoyable way possible! As a matter of fact, MANY AutoStar users are now programming their own "Tours" based on these guides, using each constellation as a separate GO TO Tour for the AutoStar library that can be added in or deleted through the main edit screen on your PC or MAC computer.

We hope you enjoy these comprehensive GUIDES to touring the constellations via your AutoStar and its computer-driven telescope. Each new installment is complete with diagrams, charts and illustrations that you will find nowhere else. Please let us hear YOUR feedback and your observations of each and every constellation after YOU have toured its vast reaches of our skies!



In addition to our regular listing of a few selected objects, I have included the complete abstract listing for twelve (12) nice galactic star clusters that are viewable in this constellation via modest instruments; that listing will be found at the end of this concise description of our Perseus TOUR.

As we explore the realm of the home of our Greek hero, I have chosen the finest (or most interesting) 12 objects in this PERSEUS "GO TO" TOUR (as with all GUIDES, all objects listed below will be visible in most telescopes (some naked eye) from the ETX 60 through the LX 90; of course larger apertures may "show" an object a bit closer and "better," but frequently a wide field and low power view is more desirable than aperture for FINDING the objects initially. Indeed, I strongly encourage you first FIND the target object, or its approximate location through your GO TO function with your lowest power and then - once IDENTIFIED positively - move up slowly in steps with magnification if necessary. Remember, not all objects "like" magnification. Sometimes better "field of view" (such as the wonderful wide fields provided by the ETX 60 and 70) is desired over light gathering (like the big LX 90) and magnification.

The rule for determining "optimum magnification" is that: 1) too low power results in sky background glow detracting or diminishing the contrast against the deep sky object; 2) too high magnification darkens BOTH the sky background AND the object; 3) medium magnification can be achieved at which you have MAXIMUM contrast between the object and its darkened background sky. I have found through three decades of direct observing that about 15x per inch aperture (36x for the ETX 60/70; 55x for the ETX 90; 75x for the ETX 125; and, 125x for the LX 90).for deep sky observing is PERFECT for most objects. That being said, always remember that DOUBLE or multiple stars require whatever power you can crank out....the seeing conditions are the limiting factor here. For a complete discussing on magnification and how it applies to YOUR telescope, visit my review at: http://www.weasner.com/etx/buyer-newuser-tips/tp_magnification.html

For my complete and comprehensive discussion regarding seeing conditions and sky transparency, see: http://www.weasner.com/etx/buyer-newuser-tips/seeing.html .

With all deep sky objects, avoid attempting to observe when the moon is in the sky, even a very thin crescent, as its brightness in the sky will overshadow the very dim contrast afforded by even the brightest deep sky object; if you see the object at all against moonlight, you will NOT see the subtle outlying areas or the full detail of what is presented.

Also, as I always suggest with all of the "GO TO" TOUR constellation lists, a good star atlas and/or chart which will list all the finest objects, constellation-by-constellation. One very handy reference guide is the PETERSON FIELD GUIDE TO THE STARS AND PLANETS, which features complete lists with declinations, right ascensions, magnitudes, and all pertinent information for you to expand your observing horizons beyond this brief GUIDE. For multiple stars and many listings of the finest deep sky objects, the classic work, Burnham's Celestial Handbook, Vol.. 3 is highly recommended.

Note that your AutoStar will NOT have every object listed on every constellation GO TO tour....this is intentional. You can access some of the most interesting objects of the sky directly from their coordinates. It is quite simple as you merely enter these coordinates as follows in the 10-step process:

1) Press the "MODE" key and hold down for 3 seconds and release;
2) Displayed will be the current Right Ascension and Declination of the center of field of view of where your telescope is presently pointed (assuming that you have properly aligned from "home position");
3) [NOTE: if you have the Meade electric focuser attached to any of the ETX or LX telescopes, holding down the "MODE" key will bring up the "Focus" command first....merely scroll (lower right scroll key) down one step to access the RA and DEC to enter your desired coordinates]
4) Press the "GO TO" button on AutoStar;
5) This will change the display and you will note the cursor blinking over the first digit of RIGHT ASCENSION (R.A.); merely use the number keys and dial in the R.A. of the object you are searching for;
6) When done, press "Enter;"
7) This moves the blinking cursor over the "DEC" coordinates;
8) [NOTE: the declination, unlike R.A., can be either positive or negative and you will see the "+" or "-" sign displayed depending on where your telescope is aimed at that time; if it is NOT the desired setting (plus or minus), merely use your arrow key to move the blinking cursor OVER the "+" or "-" sign and change by using either of your lower corner SCROLL KEYS;
9) Proceed to enter the DEC using number keys;
10) Press either "Enter" or "Go To" when finished and the telescope begins slewing to your desired object!!

The constellation tour Star Chart above (click on and save to a file on your PC; then open it and re-size to fit the page and print for a very handy at-the-scope star chart) will get you started on your journey for this constellation.

Following is the concise object list for your "GO TO" TOUR of Perseus; you may wish to find the majority of the objects from the AutoStar Library (for example, you can easily go to the beautiful and rich "Double Cluster", NGC #'s 869 & 884, if you pull up "Object/Deep Sky/NGC/..then type in '869'...." and then press "Enter", followed by "GO TO" to access this famous and rewarding wonder of our nighttime skies. On the other hand, if you want to experiment and become a "better AutoStar user" try entering the exact R.A. and DEC coordinates (given in the listing below) of that same object as described by holding down the MODE key. You will find the accuracy of entered GO TO's to be somewhat less than those stored in AutoStar, but the capability of acquiring unlisted objects is fantastic!

In addition, remember that you can GO TO this object DIRECTLY as well (as with many of the more recognized "named" deep sky wonders. Merely key in SELECT / OBJECT / DEEP SKY / NAMED....and scroll down alphabetically to "Double Cluster." Press "enter" and then "GO TO" and the telescope will take you there! Pressing "enter" again will continue to provide you with much valuable information about this object and any object that you have selected via the keypad.

You will access your FIRST GOTO target - (usually the brightest star in each constellation) - via the command "SETUP / OBJECT / STAR / NAMED....and scroll to "Algenib"", then press "Enter" and subsequently "GO TO" to move your this bright star. NOTE: the star Algenib goes by many names, but is entered into the Autostar library under that name. The most common reference to this star is "Mirfak" or "Marfak", but it is necessary to use that recorded in the A.S. library of objects. Remember also that many distinctive objects are sometimes listed among the "named" objects. So, likewise for that object you might merely go to SETUP/OBJECT/DEEP SKY/NAMED....and then scroll alphabetically to the "common" name of the object if you are not already there; press "enter" and then GO TO and your scope is off and running!

You may also access the constellation by: SETUP/OBJECT/CONSTELLATION/"Perseus".....Enter....GO TO, which will take you close to the central position of the constellation's boundaries.

    bright star - ALGENIB (alpha Persei) - R.A. 03h 21' / DEC + 49 41 - Magnitude: 1.8 - nice lavender star!
    demon star! - ALGOL - (beta Persei) - R.A. 03h 05' / DEC + 40 46 - Mag. 2.1 to 3.4 in 2.9 days!
    double star - ATIKS (omicron Per) -  R.A. 03h 41' / DEC + 32 08 - Mags: 4 & 8.5 - challenging!
    try this double - MENKIB (zeta Per)  - R.A. 03h 51' / DEC + 31 44 - Mags: 2.9 & 9.4 - a toughie!
    nice easy double - epsilon Per - R.A. 03h 55' / DEC + 39 52 - Mags: 2.9 & 8.1 - wide, fun double
    Nova Persei - GK Per - R.A. 03h 28' / DEC + 43 44 - Mags: 10.9 to 14....odd variable
    galactic cluster - ngc1245 -  R.A. 03h 11' / DEC + 47 03 - large, good for wide fields, low power
    galactic cluster - ngc1528 - R.A. 04h 11' / DEC + 51 07 - Mag: 6.2 , 80 stars - NICE, large!
    galactic cluster - ngc1342 - R.A. 03h 28' / DEC + 37 09 - Mag: 7.1, 40 stars, pretty cluster, low power
    galactic cluster - Messier 34 (ngc1039) - R.A. 02h 39' / DEC + 42 34 - Mag. 5.5, 80 stars (fine!)
    "the Little Dumbbell" - Messier 76 (ngc650) - R.A. 01h 39' / DEC + 51 19 - Mag. 11.8 - nice planetary!
    the "DOUBLE CLUSTER" - ngc869/884 - R.A. 02h 17' / DEC + 56 54 - fantastic and memorable sight!

** Plus: GALACTIC CLUSTERS IN PERSEUS:** Following is an abbreviated listing of the twelve (12) brightest and most interesting open, or galactic, clusters in the constellation of Perseus; this area of the sky if VERY rich in wonderful star fields for scanning with the very low power and wide field instruments as well as a standard pair of 7 x 50 or 10 x 50 binoculars, since it is located just on the edge of the dark and rich winter Milky Way skies. The listing following gives the NGC #, the R.A. and DEC of the object, the Magnitude, Size, # of stars and a brief and very concise description and/or notes as necessary:

ngc     RA        DEC (+)    MAG    SIZE ('arc)    #stars & description
0744    04 47    55 14        9.4        11               25 - very distant and faint, medium sized, stars faint    
0869    05 17    56 55        4.4        36               350 - "hPer", NW of the two "double clusters"
0884    05 22    56 53        4.7        36               300 - "xPer", the companion of ngc869....fantastic!
0957    05 25    57 18        7.2        10               40 - compact and fairly bright, stars about 10th mag.
1039    05 25    42 34        5.5        18               80 - M34, see description which follows
1220    05 32    53 10        11.8       02               10 - tiny and VERY faint, only 10 stars, about 12th mag.
1245    05 49    47 03        6.9        30               40 - very large, sparse but brighter stars, low power!
1342    05 58    37 09        7.1        15               40 - nice, fairly compact scattering of 9-11 mag. stars
1444    06 11    52 31        6.4        04               15 - tiny, but fairly distinct; use medium mag. for this one
1513    06 46    49 23        8.8        12               40 - not so bright, but many stars about 10-11 mag.
1528    04 11    51 07        6.2        25               80 - very nice, often overlooked, fairly bright, low power!
1545    04 17    50 05        8.9        18               25 - faint, and very sparse sprinkling of stars



Object 1 - Our "Starting" Bright Star - "ALGENIB" (alpha Persei)
Also known as "Al Genib", "Al Chemb," "Mirfak" (most common), and "Marfak," alpha Persei has gone by many names - all Arabic - over the centuries. Although Autostar and other popular GO TO hand control libraries refer to this star as "ALGENIB", this name is shared with other stars of the sky, notably and most confusingly Gamma Persei and also nearby Gamma Pegasi!! The most common association with this star by far is "Mirfak," which translates as "elbow of the Hero," or "Perseus Elbow." This huge and bright (4,200 more than our own sun!) star is 570 light years distant, making it one of the most remote of all 1st magnitude (it is actually magnitude 1.8) stars. This star is surrounded by an absolutely beautiful field of stars for the casual scanning with binocular or small richest field telescope. Wide field views reveal thousands of stars surrounding Algenib, particularly a group of fairly bright stars immediately surrounding the bright star for as much as 2 degrees. This is a true physical cluster with nearly 110 stars appearing to be gravitationally held along with Algenib; this cluster will be overlooked in the telescope; use either a very wide field, low power richest field scope or binoculars......you will then see this often missed cluster, one of the closest to our solar system!

Object 2 - THE DEMON STAR - "Algol"
You can be the judge on which version/story led to the actual naming of this star. Algol is one of the most famous of all variable star, and is the ONLY variable to have its own "home" on your Autostar whereas you can actually determine the upcoming minimum brightness of this star by going to SETUP / SELECT / EVENT / [scroll down to "Minimum of Algol and press "enter"]...

The star is so precisely synchronized in its variation (from magnitude 2.13 to 3.40 in exactly 2.86739 days) that you can actually SET YOUR ACCURATE WATCH by this star! However, if you want even MORE accuracy, slew to R.A. 04h 44m / DEC + 36d 38m to the variable "AW Persei" nearby, which varies from magnitude 7.96 to 9.08 is exactly (and I mean EXACTLY!) 2.02873293 days! Both stars are "eclipsing binaries" and are discussed in my article on Algol at: http://www.weasner.com/etx/buyer-newuser-tips/algol.html .

The actual common name in use today comes from the Arabic "Al Ras al Ghul", or the "head of the demon," referring to Medusa's head (see explanation above) as Perseus is holding in his left hand. Does this reference then, elude to the "Demon Star" from such a designation? One would think so, unless further ancient mythology is revealed. The Hebrews referred to this star similarly, but having NOTHING to do with Medusa nor Perseus as a hero....it was "Rosh ha Satan" or "the Head of Satan" to their scholars. This designation has NOTHING to do with wicked women...only the fact that this star to the naked eye DOES change its appearance, among thousands of stars well known to the ancients that DID NOT vary at all....so something must be "different," or "evil" about this flickering heavenly light!

So, perhaps the name comes from its variability, or from its association with the wicked Gorgon Medusa....or both. It is yet another interesting similarity in ancient star lore by two totally separated cultures and time, yet the ultimate translation results in great similarity. I have discussed this curiosity of the human mind and association with "the Great Bear" of Ursa Major, being so associated by both the Greeks and the Chinese, through wide spans of time, though no contact was apparently made between the two people to share such knowledge.

At three million miles in diameter, this star (the larger primary) is about three times larger than our own sun and is located fairly close to us, at about 100 light years.

Object 3 - Double Star "ATIKS" - Omicron Persei - A challenging object
This is a very difficult double star for the 5" or 6" telescope even though the separation is a full 1.0" arc; the primary star is magnitude 4.0, while the "B" star is much dimmer, only magnitude 8.5. Also known as 38 Persei, the primary ("A") component is a very slight variable although it will not be noticeable to the visual observer. Look for the fainter companion star nearly northeast of the brighter star. This is not as easy as you might think even in an 8" telescope!

Object 4 - Another Good Double - Zeta Persei - MINKIB (also home of the "California Nebula")
This area gives you double for the money. Zeta Persei, a nice and colorful double star for most telescopes, a rapidly expanding group of associated stars and the "California Nebula," ngc1499, a 2.5-degree streak of nebulosity to the immediate north of Zeta. For reference, Zeta marks the "foot" of Perseus. Zeta, along with omicron, xi, chi, 40Per, 42Per and about half-dozen more stars are all moving rapidly AWAY from a common center just north of Zeta which most likely was their place of "birth." Indeed, it is thought that the California nebula is a remnant of the large cloud of primordial gases and dust that eventually led to the formation of these - and perhaps other - stars. This group, and their trajectories, I have plotted on the following Lowell Observatory photograph.


Zeta is a nice double star, magnitude 2.8 for Zeta with a magnitude 9.4 companion a full 13" arc nearly due south of the brighter star. This should be an easy object for 3" and larger scopes with medium magnification, but a bit tougher for smaller apertures due to the great difference in brightness between the two stars. Look for some nice color contrast here, with Zeta appearing almost green while the fainter star - with medium to high magnification - appearing pretty much dull blue.

NGC 1499 is immediately north of Zeta about 5 degrees; this is a huge (nearly 3 degrees E-W) cloud and very difficult to make out visually; piggyback photography reveals it quite easily on red-sensitive film. A good "nebula filter" on a very dark night with the widest possible field your scope can offer "amy" reveal this 4th magnitude (but spread out!) cloud of primordial gases.

Object 5 - A Fine Double Star - Epsilon Persei
Here is an excellent, but not so easy double star with a wide magnitude difference from the primary (mag. 2.9) to the secondary star (mag. 8.1). Look for the fainter star nearly 10" arc away almost due NORTH of the brighter star. Look for the striking color differences as well in these two stars. Most observers see Epsilon (the brighter one) as a blue-yellow color, while the fainter companion is almost "gray" or a steel blue color. Medium, to medium-high magnification is required even with such a great separation, this due to the wide difference in brightness between the two components.

Object 6 - An Unusual Old Nova that is "Still Around!" - Variable Star GK Persei
This is a very interesting star to observe and to at least say "I have seen it...." Observe this area ONLY in medium magnifications for best views, but to observe the light fluctuations and monitor them carefully of GK itself, you will need to use at least 175x to 200x for accuracy (and probably to even locate the star!). Let's start with the star itself and the Nova of 1901. This now-faint star reached a magnitude that rivaled all but the fifth brightest stars of the sky, magnitude 0.2 on February 23 of that year. Only two days prior it was at magnitude 2 or 3, skyrocketed to brilliance and then fell to below naked eye view just as quickly. However, it was monitored and verified by astronomers around the world, with Perseus high in the winter sky. Using detail sky charts supplied by the American Association of Variable Star Observers (AAVSO), this star can be monitored nightly (and should be!) with users of 5" and 8" telescopes as a very faint 13th magnitude rapidly fluctuating star. Without warning or any hints of activity however, it can suddenly surge to 10th magnitude for a brief period and then subside once more.

To locate and monitor this chart, merely go to: charts.aavso.org/standard/PER/GK_PER/GKPER-DR.GIF . This is the high power, narrow field "d" chart that shows stars to magnitude 13.9 very close to GK Per. It will assist you in finding this faint star among the others and also give you actual confirmed magnitudes of others star with which to compare. NOTE that this is the "reversed" chart made specially for users of catadioptic telescopes such as our GO TO scopes, and thus NORTH is at the top and EAST is to the right, just the way it appears in the eyepieces of Schmidt Cassegrain and Maksutov telescopes.


Note in the light curve from 1901, adapted from that compiled at the Harvard College Observatory in Cambridge, Mass, the star's incredibly rapid rise to maximum, followed by an equally impressive demise. The fluctuations around 6th magnitude continued throughout the remainder of 1901 after which the star slowly faded to its present-day 13th magnitude; HOWEVER....the fluctuations we see today are almost exactly as you see on this chart around the 6th magnitude range, except the star is 7 magnitudes dimmer now, curious RIGHT ABOUT the magnitude the star was PRIOR to this remarkable outburst that placed it 210,000 times more luminous than our own sun! This star deserves to be monitored by observers in telescopes 5-6" inches and larger on a regular basis, with all observations of activity reported to: www.aavso.org. For astrophotographers with large telescopes, there is some nebulae (planetary nebula gas residue) that now surround the remains of this famous nova.

Object 7 - A Nice Galactic Cluster - NGC1245


Here is a nice cluster that is easy to locate even small telescopes directly south of Alpha Persei by about 3 degrees. It contains nearly 100 stars of nearly equal brightness as can be seen in the photograph above from the 13" telescope at Lowell Observatory that was used in the discovery of the planet Pluto! It is a very rich cluster and quite large, almost identical in sky area to the disk of the moon (30' arc). The 5" scope will clearly show many of the individual stars, but the 8" will reveal its true beauty. Since the cluster is nearly 1/2 degree, wide field and very low power views are desirable, something that limits the ability to see the faintest stars except in the larger apertures. It appears as a nice round "smudge" in smaller instruments, but is located in a VERY rich and rewarding part of the Perseus Milky Way near Algenib (see above).

Object 8 - Another Nice Fall Cluster - NGC 1528 & 1513
Another "double for your money object", when searching out ngc1528, you can also spend some time exploring the slightly fainter and 1/2 size ngc1513 to its SW by only 2 degrees! NGC 1528 is a very large (25' arc) open cluster with about 80 stars that are fairly bright 8 to 9th magnitude, thus making this an exceptional cluster for small telescopes and even binoculars. When viewing telescopically, very low, wide field views are a must to get the true "cluster effect" realized. This is one of those clusters that reveal more beauty to small, richest field instruments than to larger "big dog" telescopes, so "...this one's for YOU," small scope users! On the other hand, larger scopes will greatly appreciate their increased aperture when it comes to exploring the exciting ngc1513....look for some 44 stars grouped in an area about 12' arc, half the size of ngc1528, and all about an equal magnitude 11. This will appear like sprinkling sands in sunlight with the 8" at about 80x to 120x magnification. The cluster IS resolvable in the ETX 90 though with difficulty and requiring very dark skies.

Object 9 - Yet Another Perseus Galactic Cluster - NGC 1342
Unlike the previous two clusters, ngc 1528 and 1513 which are very symmetrical and uniformly shaped, ngc1342 - located midway from Algol to the "foot" of Perseus (zeta Per) - is an irregular galactic cluster. It is quite large (half the size of the moon's apparent disk, 15' arc) with some 50 stars scattered loosely within this area. Most stars are of 8th and 9th magnitude and this cluster, being in an uncharacteristically star-poor area of central Perseus, is a easy target for even small scopes, with its total integrated magnitude of 7.1 visually.

Object 10 - Messier 34 - A Fine Galactic Cluster in Perseus **Pair of Double Stars as a Bonus!**
Don't get me wrong, as I still consider M-34 a fine cluster, with a total magnitude of 5.5 containing over 80 stars packed into a large 18' arc area of sky, right on the western border of Perseus, nearly into eastern Andromeda. However, I still marvel at the fact that this object - which is barely visible in a finderscope and not attainable in today's skies with the naked eye - was warranted a listing by Charles Messier in his famous group of objects, yet the much BRIGHTER and LARGER ngc869 and ngc884 (the two clusters of the "double cluster", below) were ignored in his listing! Look a full binocular field northwest from Algol for this very bright and conspicuous cluster of 8th through 13th magnitude stars, certainly NOT a disappointment by any means (but I am still upset with Mr. Messier and have informed him of that fact).

Always use the lowest power and widest field of view possible in your telescope to view this bright scattering of stars located nearly 1500 light years away. Indeed, the true beauty of the cluster is often lost in larger telescopes and the use of higher magnifications leads to disappointment. However, larger telescope will enjoy the BONUS two double stars that are located in this wonderful object! Look carefully at the photo/chart below: first (north, near the center of M-34) is the twin 8.5 magnitude star pair "h1123", a brilliant white grouping of two stars identical in color and brightness! This is a very easy pair, with a full 20" arc of black sky separating the two...they will appear as two of the brightest stars in this cluster. Note that my chart has NORTH at top and EAST at the right, exactly as the image will appear in the Maksutov or Schmidt Cassegrain telescope with the diagonal mirror/prism in place.


Look near the cluster's edge, only about 6' SE (lower left in the photo) of the first double for "Struve44", a very close double (1.0" arc) that is a challenge for the ETX 125 and likely beyond the resolution of smaller telescopes. These stars likewise are about 8.2 magnitude, with the fainter one being to the northeast (Position Angle 55 degrees) of the main star.

Objects 11 - The "Little Dumbell" Nebula - Messier 76
This faint planetary nebula is easily located within the same very low power (i.e., a degree field of view) as the brighter star Phi Persei, the westernmost bright star in the constellation and right on the Cassiopeia border. Although this fairly large (157" arc long by 87" arc wide) box-shaped nebula is only assigned a faint magnitude 12.2, I have seen it steadily many times in a 3-inch Questar at 80x. This is a large object, so increasing the power past 30x per inch results in losing it altogether. It is remarkably easy in the 8" scope, with the "dumbbell" shape clearly discernible against a beautifully black star-speckled field of view. I will not argue with the estimate of brightness, but it has always been my experience that this object is brighter than the assigned 12th magnitude. At any rate, it is a challenge and an object certainly worthy of locating.


Objects 12 - NGC 869 and NGC 884 - the "DOUBLE CLUSTER"


This is undoubtedly the finest star cluster in the sky for small telescopes; it is richer in stars (a total of 650+ in both clusters!) than the beautiful "Wild Duck" cluster, Messier 11; it is far more fascinating telescopically than either M-45 (the Pleiades) or the Beehive in Cancer. It is truly a sight to behold in good binoculars on a dark and moonless night when the hero Perseus glides silently overhead with the "Demon Star" carried behind him....

In the photograph above, north is at the top and clearly shows the appearance of this cluster in wide field telescopes with a limiting magnitude of about 11. This photo was taken on red-sensitive film in 1978 through a 200mm f/3 lens guided piggyback for 20 minutes from the observatory on Petit Jean Mountain.

The double cluster has always acted as a "beacon" of sorts in my astronomical pursuits, its position conveniently plotted midway between Gamma Persei and Epsilon Cassiopeia; on the darkest nights the naked eye can perceive of the wonder of these two jewel boxes of the sky, with sparkles hinting of what must lie in wait of telescopic enhancement. In mythology it is these two groups that signify the actual "handle" of Perseus' great sword with which he slew the Gorgon Medusa.

Use the lowest possible magnification - and a wide field of at LEAST one full degree - to take in the entire expanse of these two magnificent clusters; indeed, even outside of the clusters themselves, the star field of the fall Milky Way is overwhelming and one can spend hours scanning slowly through the nearby neighborhood of these two wonderful galactic star clusters. In reality, these two clusters are fairly far away, at a distance of nearly 7,500 light years. Compare that with other famous clusters (the closest to us listed first):

1. The Hyades - Taurus - 130 light years
2. The Pleiades - Taurus - 450 light years
3. The Beehive - Cancer - 525 light years
4. The Wild Duck - Scutum - 5500 light years
5. The Double Cluster - Perseus - 7500 light years.

There are likely as many as 400 stars in ngc869 while almost the same number (320) are thought to be in nearby ngc884. NGC 869 is the cluster more north and west; the 4th magnitude star "10 Per" is embedded in the extreme southeastern edge of ngc884.



Now here is a totally different GO TO "User Object" for you....we are not actually going to enter an "object" as you might think it, but rather a "position" that will become very important for you at least one or two nights out of every year. You will thank me on those occasions around August 11-12 each year when the moon is absent from the sky.In August 1971, when I had the world by the tail and thought I had pretty much seen it all in astronomy, I was taking part in a huge - the first of its kind in Arkansas - public star party that brought literally over 10,000 people to a small hilltop near a community park. There were guest speakers and telescopes from all over the south at this event. Mars was at its closest point since 1956 and the moon had already set for the evening.

There was a small Questar 3" telescope mounted far off from the crowd, the scope we later learned was owned by a prominent banker from Hot Springs, Arkansas. His tiny chrome telescope peered diligently toward the constellation Perseus, which was just coming up in the low northeastern skies.

"Whatcha' looking at?" we asked in our attempts to bring the gentleman more into the spirit of things from his shadowed hide-away. Without even moving from the eyepiece, he said,

"Perseid Meteors."

Perseid meteors?! Well, we were quick to explain that you did NOT need a telescope to observe meteor showers, that the best way is with the naked eye from the comfortable reclines of a soft lawn chair.

"Nope...." he grinned as he replied. "Take a look."

And there, aimed dead center at R.A. 03h 00m and DEC + 58 degrees 30 minutes, his telescope was locked right onto the RADIANT of the famous Perseid meteor shower which was peaking the next evening. And, yes, he WAS looking at meteors.....like lightening bugs headed right for your windshield on a hot Arkansas night, the faint meteors appeared to be heading right for us, just like "warp 1" throws the stars right into the screen of the U.S.S. Enterprise as Kirk gazes "out there."

I had never seen anything like it and would TODAY not believe it was possible had he not shown that phenomenon to me....debris from the once-glorious comet Swift-Tuttle actually streaming out of its path and vaporizing as it encountered the Earth's atmosphere. I have seen this sight many times after that, but have not seen the gentleman who put me on to this wonderful opportunity since.

The Perseid meteor show radiant is located at coordinates: R.A. 03h 04m and DEC + 58 00m, and can be found marked as the red "X" on this "GO TO" GUIDE star chart for Perseus (above).

On AutoStar, go to: "Select/Object [enter]...." scroll down to "User Object" [ enter]. Now enter the coordinates given above for "Perseids", using the number keys on AutoStar. After entering the coordinates and pressing "Enter" yet again, scroll down one and you can list the magnitude of the object as "1"[Enter].

Perhaps with this very unique addition to your GO TO user objects, YOU can impress some unknowing individual or group at your next August star party! It is truly a sight to behold, and must be caught within one or two days either BEFORE or AFTER the actual maximum; for the best results observing this tiny "opening" of the sky within 6 hours of maximum will reveal a spectacular show!

Next Constellation GO TO" TOUR Installment: TAURUS, the might bull of the sky, with its red eye zeroed in on the sky's great hunter, Orion. We will explore the remarkable Hyades and even more fascinating cluster of the Pleiades, or "Seven Sisters." In addition, we will investigate the object that "started it all"....Messier 1, the Crab Nebula, so faint and fuzzy that even Messier was likely shocked that he found the thing!

Good Observing and may the stars serve as your sentries as you explore the frontiers of space!

P. Clay Sherrod
Arkansas Sky Observatory
Conway / Petit Jean Mountain

Return to the top of this page.

Go back to the Observational Guides & References page.

Go back to my ETX Home Page.

Copyright ©2001 Michael L. Weasner / etx@me.com
Submittal Copyright © 2001 by the Submitter
URL = http://www.weasner.com/etx/ref_guides/perseus.html