Deep Sky Object Observation Planner Spreadsheet in Excel with Utility Calculators and Bibliography - project homepage

K. Fisher Rev. 5/3/2007

Quick Start Download component spreadsheet(s) User Guide Condensed List in HTML Observing List All - Dump Excel to HTML (8.4Mb)


This project is an observation planning spreadsheet implemented in Microsoft Excel (2003) suitable for beginner or intermediate deep sky observers. The spreadsheet contains a catalogue of approximately 3,100 deep sky objects and regions which can be sorted and filtered by whether they are currently visible in the observer's local horizon system. This deep sky object ("DSO") observing spreadsheet will be of interest to instructors of introductory college astronomy courses, astronomy club lunar party organizers, and intermediate and beginner observers. By using the full power of Excel's drill-down data filter feature, a variety of interesting DSO tours can be developed, e.g. - by open cluster age, by bright star MK spectral class, by binary star separation, by galaxy type, by Milky Way structure association, etc. For beginners, purchasing a commercial observation planner product like Astroplanner software by Paul Rodham (iLanga, Inc.) is a better alternative. But beginner observers who wish to experiment with observation planning without an initial capital outlay may find this spreadsheet useful for learning observation planning technique. This author uses Astroplanner in conjunction with the spreadsheets provided here.

Quick Start

  • Download the main catalogue spreadsheet in MS-Excel (13.2Mb). Open the spreadsheet and allow macros to run.
  • In worksheet "SettingsObserver" in the blue highlight cells, enter your age and observing experience.
  • In worksheet "SettingObservingPoint" in the blue highlighted cells, enter the terrestrial longitude and latitude for your observing point in integer degrees, minutes and seconds.
  • In worksheet "SettingSessionObservingRange" in the blue highlight cells set the altitude range you desire to observe with using a telescope and/or binoculars.
  • In worksheet "SettingSkyBrightness" enter the anticipated sky brightness at your observing site in the blue highlighted cells B21:C21. Use magnitudes and magnitudes per square arcsec (MPSAS). The calculator in cell B15 will convert magnitudes to MPSAS.
  • In worksheet "SettingObservingTime" in the blue highlighted cell B5, enter your UTC offset.
  • In worksheet "SettingObservingTime" in the blue highlighted cells B30:B31 and C30:C31, enter the beginning and ending times for your anticipated session. In general, limit your self to a 3 or 5 hour observing session.
  • Entering a new observing time in cells B30:B31 forces recalculation of the entire spreadsheet. Wait approximately 30 seconds for the entire spreadsheet to recalculate.
  • Go to worksheet "MainCatalogue". This worksheet contains a catalogue of approximately 3100 deep sky objects with 80 fields (columns) of characteristics for each object. Use the full power of Excel's data filter feature to drill-down to the desired object. While there 80 columns of characteristics to choose from, that offers endless ways to drill-down to desired objects, some of the basic filter fields are:
    • Filtering for "TRUE" on column E ("IsVisZenithalSessionDuring") filters for objects that will be in the zenithal observing zone during your observing session. Filtering for "TRUE" in column G ("TransitsSessionDuring") filters for objects that will transit during your observing session.
    • Column H filters for object type.
    • Column I filters for apparent magnitude. If there is no known magnitude for the object. This field is set to magnitude "99.0".
  • External content hyperlinks to CDS Simbad to research an object in more depth is available in column F ("Cat_IdSimbad_Link") of "MainCatalogue".
  • If desired, in worksheet "SettingsTelescope", enter the characteristics of your current telescope eyepiece combination.
  • Some characteristics were added to the far right-hand columns after a section of working variable columns. See "MainCatalogue" worksheet at columns DB through DH.
  • Columns BW to DA in "MainCatalogue" are computation fields used by the catalogue and should not be changed.
  • The spreadsheet catalogue is set to automatic recalculation. Recalculation is normally triggered by changing the beginning observing time in worksheet "SettingObservingTime", Cell B31.
  • The spreadsheet is currently filled-out nearly to the practical computation limits of Excel - about 3,100 rows - constrained by user-friendly recalculation time. At this volume of computation, recalculation takes about 15-20 seconds. Allow the spreadsheet to fully recalculate before filtering the primary catalogue worksheet "MainCatalogue". The standard MS-Excel menu command "Tools | Options | Calculation | Manual / Automatic" can be used to toggle to manual recalculation.

  • If on first start-up, the spreadsheet does not recalculate and gives a "Value" error in many fields, see the help notes on forcing recalculation.
  • If when opening dependent spreadsheets, like the HTML generator component (see "Download components" below), the spreadsheet that is dependent on and linked to ObsSpdt.xls does not link, use the Excel menu options "Edit | Links | Change Source" to refresh the link between the spreadsheets.

Optional Quick Start

Static copy grab

  • Instead of downloading dynamic Excel content, a static copy of the list can also be downloaded in a raw Excel to HTML dump (8.4Mb). This HTML version of the list of 3,089 objects contains all coded charactertistics. Must modern spreadhsheets can import raw HTML.


Development from a beginner into an intermediate and then an advanced observer depends on in part on maximizing the amount of time spent at the eyepiece. In the time-deprived post-industrial life-style, getting to the eyepiece consistently to view 3 or 4 objects a night is difficult. One way to increase the amount of time spent at the eyepiece is efficient observation planning. With modern observation planning techniques, it is possible to quickly select three or four targets for any clear night, appropriate either for dark sky sites (galaxies, clusters and nebula) or light-polluted urban settings (bright doubles and variable stars and the Moon).

To observe the efficiently is dependent on having a good catalogue of interesting objects and the ability to determine the current location of objects above the observer's local horizon by object type. Typically, this may involve reviewing several books and guides for appropriate targets applicable to a particular night, such as Burnham's, Harrington's Touring the Universe with Binoculars, Mullaney's Celestial Harvest, or Peterson's Field Guide to the Stars and Planets, just to name few options. Finding the right targets is confounded by the repetitous and out-dated designations. Various DSO lists are familiar to most amateurs, such as Messier, Caldwell, the Herschel 400 and R.N. Clark. Expert astronomer recommended object lists are another source for the ideal narrowed DSO list. Prominent among such lists for deep sky objects (DSOs) are Steve Gottlieb's list of 662 DSOs incorporated into the chips of many digital setting circles such as the Skywizard, Lumicon's "Sky Vector" and Celestron's "Astromaster", Appendix E to R.N. Clark's classic book Visual Astronomy of the Night Sky, the Alan Dyer's Finest NGC List, the Royal Astronomical Society of Canada Deep Sky Challenge List, Messier's list (at the Astronomical League), Caldwell's catalogue (at SEDS), and Bill Arnet's implementation of the Herschel 400 (also available at the Astronomical League).

After using such guides and lists for a few years, it became apparent that many of the guides involve a core of common objects around which a lifetime observing program could be built. Using commercial observing planning software, it was possible to get at parts of a core observing list, but this involved loading catalogues containing numerous entries beyond the reach of most amateur telescopes of 10 inches or less aperture. Loading such catalogues also involved numerous duplicate records that had to be resolved in order to reach a final list for a particular night.

The solution of reviewing several guides and preparing an intermediate-sized life-time list of less than 3,000 objects accessible by smaller aperture telescopes appeared to be an appropriate solution. An "intermediate-sized" observing list here means more than the 400 in the Herschel 400 but less than the 10,000 objects that can be found in a typical modern galaxy catalogue. Appendix "E" in R.N. Clark's Visual Astronomy of the Deep Sky (approx. 620 objects) is in a similar vein, as was Steve Gottlieb's Non-stellar and Stellar observing catalogues (approx. 1,200 total) incorporated into many hand-controllers, and Mullaney's Celestial Harvest (500 objects). In short, review multiple guide books and build one list, in order to spend as much time in the future at the eyepiece. With such a catalogue, regardless of whether an observer is in an urban light polluted or rural dark sky setting, a few interesting objects could be quickly located on any given after-work night.

This project's DSO observing spreadsheet also was created out of a desire to have an observing tool that was more generic and flexible than commercial observation planning products and that could be carried around with the user on a data device like a jumpdrive. I was also interested in study astronomical math algorithms. The implementation vehicle chosen was Microsoft Excel. Excel is widely distributed in office environments. Thus, during a workday break, it is possible using this spreadsheet to quickly select a few objects for after work observing or to plan an astronomy club party.

Other features included in this DSO observing spreadsheet are a means to quickly move target lists to HTML tables for redistribution over the web.

Catalogue Description

The DSO observing spreadsheet catalogue contains approximately 3,100 objects. Spreadsheet Tab MainCatalogue. The catalogue was developed by the following means. CDS Simbad database was as the preferred source for object positions and names. Object names and positions located in various reference lists were checked against the Simbad J2000 position.

  • DSO extended objects: Several popular guides were reviewed for showcase item lists. These included Clark, Herschel 400, Barnard, Caldwell, Messier, Burhnam's, and Harrington's TUBA. A consolidated non-duplicative list of approximately 1,200 DSO objects was created from these lists. Supplemental items were added according to the author's interest and personal knowledge. A major deviation from the general intent of this project was the inclusion of Arp's Peculiar Galaxy catalogue of 343 galaxies and all of Barnard's 348 Dark Clouds regardless of visibility. This deviation was based on the author's personal preference. The following table summarizes the sources:
  • Table 1 - DSO Source Catalogues providing object entries
    Source catalogueCount of catalogue objects from
    R.N. Clark's DSO Catalogue Appendix E (Includes all Messier's list)611
    Herschel 400 - Supplemental objects not in Clark187
    Barnard Dark Clouds348
    Caldwell's List - Supplemental objects not in the above18
    O'Meara's DSO list - Supplemental objects not in the above3
    Mullaney's Celestial Harvest - Supplemental objects not in the above13
    Quasers visible to amateurs - McGaha, J. March 2006. The Outer Limits: Observing Quasers at High Redshifts. S&T. 111(3):69-724
    Arp Peculiar Galaxies (of special interest to this author)343
    Hubble Famous Photographs - selected by this author20
    Molecular Clouds Complexes - Dame (1987), Perrot (2003) and others18
    Milky Way Dwarf Galaxies - recent discoveries2
  • DSO type distribution:
  • Table 2 - Distribution of 1419 DSOs by major type
    Type Count
    Galaxy 683
    Globular Cluster 87
    HII Region 18
    Molecular cloud 10
    Neb Bright 8
    Neb dark 353
    Open Cluster 196
    Planetary Nebula 57
    Radio source 2
    Supernova Remnant 5
    Grand Total 1419

  • Supplemental characteristic coding of DSO extended objects: The following supplemental characteristics were coded in the catalogue for DSO objects:
    1. Distance: Based on the following sources:
    2. Table 3 - Supplemental sources for distances in the catalogue

      Source External hyperlinks
      Cox, Arthur (ed). 2000. Astrophysical Quantities (4th ed.). Springer.
      Acker, 1992. Strasbourg-ESO Catalogue of Galactic Planetary Nebulae
      Table 22.2 - Nearby galactic open clusters in Allen's Astrophysical Quantities (ed. 2000) - from (adjusted) Lynga, G. Catalogue of Open Clusters Data, 5th ed.
      Table 23.6 - The Local Group in Allen's Astrophysical Quantities (ed. 2000) - after van den Bergh, S. 1992 MNRAS, 255, 29pp and Tully, R.B. 1987, Nearby Galaxies Catalog (Cambridge Univ. Press)
      Table 23.7 - Bright galaxies in Allen's Astrophysical Quantities (ed. 2000) - after de Vaucouleurs, G. et al. 1990. Third Reference Catalogue of Bright Galaxies (Univ. of Texas Press) and Tully, R.B. 1987, Nearby Galaxies Catalog (Cambridge Univ. Press)
      Dame, T.M. et al. Nov. 1987. Molecular Gas within 1 kiloparsec of the Sun. Table 2 in A composite CO survey of the entire Milky Way. 1987ApJ...322..706D
      Dias, W.S. et al. July 2002. New catalogue of optically visible open clusters and candidates. 2002A&A...389..871D
      Fich1984: Fich, M. & Blitz, L. 1984. Optical H II regions in the outer galaxy. 1984ApJ...279..125F
      Harris W.E. 1997. A catalog of parameters for globular clusters on the Milky Way. 1996AJ....112.1487H CDS Catalogue VII/202
      Hilton, J., Lahulla, J.F. 1995. Distance measurements of LYNDS galactic dark nebulae. 1995A&AS..113..325H CDS Cat. no. J/A+AS/113/325
      Kerr, F.J. 1969. The Large-Scale Distribution of Hydrogen in the Galaxy. (Review) 1969ARA&A...7...39K
      Paturel, G. et al. HYPERLEDA Catalog of Galaxies, Version 2003 CDS Catalogue VII/237 (Catalogue of Principal Galaxies)
      Lynds, B.T. Jan. 1962. Lynds-Barnard Cross-Reference, Table 1 in Catalogue of Dark Nebulae. 1962ApJS….7….1L
      Skiff, Brian. 1999. Observational Data for Galactic Globular Clusters. NGC/IC Project Website.
      Taylor, J.H., Corders, J.M. Jul. 1993. Pulsar distances and the galactic distribution of free electrons. 1993ApJ...411..674T
      Tully, R.B. 1988. Nearby Galaxies Catalogue. Cambridge. Univ. Press. CDS Cat. VII/145
    3. CDS Simbad object type
    4. RC3 Galaxy Type
    5. Arp Interacting Galaxy Type
    6. Computed Magnitudes Per Square Arcsecond (MPSAS): Per the method described in Clark' Appendix E.
    7. Catalogue cross-references: Clark, Arp, Messier, Herschel400, Barnard, Lynd's Dark Nebula, PGC and Bennett's list of southern hemisphere showcase objects, including Principal Catalogue of Galaxies id number for "The Sky" users.
    8. Open cluster age: After Allen's Astrophysical Quantities.
    9. Age histogram of open clusters
      Figure 1 - Age Distribution of Open Clusters and Clusters of Stars in a subset of approx. 823 DSOs in the catalogue

      The galactic year, the time it takes the Sun to complete one revolution around the Milky Way's core, is approx. 220 million years or 8.34 log10(years). Half of all open clusters disperse in just under one galactic year (8.13 log10(years) or 218 million years). The third quartile of open clusters disperses in just under two galactic years (8.6 log10(years) or about 430 million years).

      Popular old clusters and moving groups that have survived more than two galactic years and into the fourth quartile include M044 (Beehive Cluster), M048, M067, M073, M093, the Hyades Moving Group, and the Coma Berenices Star Cluster.

      The youngest clusters in the catalogue are aged around 6.7 log10(years) or approx. 5 million years old. The youngest three are the Tau CMa Cluster a.k.a. the Northern Jewel Box (NGC2362, Caldwell 64); NGC1980 surrounding iot Orion in the Orion stellar nursery region; and, NGC2239, a star cluster associated with the Rosetta Nebula stellar nursery in Mon.

      Table 4 - Frequency of Open Clusters by V magnitude and major axis size (arcmins)
      Mag/Size 1-9 10-14 15-24 25-54 55-94 >95 Unknwn Total
      2-5 4 6 11 13 5 39
      6-7 26 14 26 9 1 76
      8-9 28 7 7 1 1 44
      10-11 8 1 9
      12> 1 1 2
      Unkwn 5 2 3 3 1 1 15
      Total 72 29 47 26 8 1 2 185

      Notes: Excluding one cluster in the Tarantula Nebula for a total of 186
    10. Globular cluster characteristics
      • Globular cluster Fe/H ratio: After Allen's Astrophysical Quantities.
      • Globular clusters populations

      • Metallicity of Globular Clusters
        Figure 2 - Metallicity Distribution of Globular Clusters in a subset of approx. 823 DSOs in the catalogue

        There are two populations of globular clusters divided by metallicity. Zinn (1985). The smaller population has high metallicity, is redder in color, is within 7 kpc of the galactic core and is flattened in shape. The larger second population has lower metallicity, is bluer in color, generally is beyond 7 kpc of the galactic core and is spheroid in distribution. Both populations were formed across a span of 13 to 9 billion years ago, with some bias towards the high metal population being formed more recently. Chaboyer (1996). How the two populations of nearly equal-aged globulars formed in the Milky Way with differing metallic contents still remains under investigation. There are competing hypotheses. Pulliam (Mar. 2006, S&T); Brook (2003) (hierarchical consolidation); Martin (2004) (Canis Major Dwarf galaxy accretion); Forbes (2004) (not Canis Major Dwarf galaxy accretion).

      • Globular cluster magnitude and size

      • Table 5 - Frequency of Globular Clusters in a subset of approx. 823 DSOs in the catalogue by V magnitude and major axis size (arcmins)
        Mag/Size <5 5-10 >11 Total
        <7 5 8 13
        7-8 7 19 3 29
        9-10 30 5 1 36
        11> 4 4
        None 3 1 4
        Total 44 30 12 86
    11. Planetary nebulae magnitude distribution:
    12. Table 6 - Frequency of Planetary Nebula magnitudes and size in a subset of approx. 823 DSOs in the catalogue by V magnitude and major axis size (arcmins)
      Mag/Size <2 2-10 12-60 60> Total
      <10 7 1 1 9
      10-11 9 2 1 12
      12-13 5 1 1 7
      14-15 5 3 2 10
      16> 1 1 2 4
      Unknwn 5 5
      Total 32 5 8 2 47

      Planetary nebula ages are not coded in catalogue, but have been measured to 40 million years. Xilouris (1996). Planetary nebulas begin with their characteristic end-view circular shape seen in M57 (M57 at SEDS), M27 (M27 at SEDS) or the Helix Nebula (NGC 7293 at SEDS). As time progresses, interstellar wind or the effects of nearby bright stars degrades this shape and they dissipate into the interstellar medium. See Xilouris (1996).

      While planetary nebula may be spherical in their early stages of mass loss, they may not remain so. In later stages, they can become elongated symmetrical tubes, as illustrated by a Hubble Space Telescope picture of the PN MyCn18. Space Sci. Instit. 1996. Planetary Nebula McCn18: An Hourglass Pattern Around a Dying Star. Photo STScI-PRC1996-07. This nebula has a strikingly similar appearance to M57 and the Helix nebula, but is viewed from a side angle instead of "end-on."

    13. Dark nebula opacity: Barnard's Dark Cloud Catalogue was cross-referenced with Lynds's dark nebula designations. Where matched, Lynds's opacity index for the cloud was included in the catalogue entry:
    14. Distribution of dark cloud opacity
      Figure 3 - Distribution of dark cloud opacity

    15. Galaxy distribution by type, size (arcsec) and magnitude: Where both magnitude and a major diameter size in arcsecs are available, galaxies in the catalogue have the following distribution:
    16. Distribution of 685 galaxies by Magnitudes per Square Arcsecond (MPSAS)
      Figure 4 - Distribution of 685 galaxies by Magnitudes per Square Arcsecond (MPSAS)

      Table 8 - Distribution of 705 Galaxies with known R3C (modified de Vaucouleurs system) assigned morphology codes
      Type Description_______________ No stage 0 1 2 3 4 5 6 7 8 9 Grand Total
      E Elliptical 16 13 12 11 8 5 7 3 75
      L Lenticular 28 1 29
      LA Lenticular non-barred 14 1 15
      LAR Lenticular non-barred with inner ring 7 5 12
      LAS Lenticular non-barred s-shaped 3 5 8
      LAT Lenticular non-barred mixed 1 1 2
      LB Lenticular barred 4 2 6
      LBR Lenticular barred inner ring 6 1 7
      LBS Lenticular barred s-shaped 6 6 12
      LBT Lenticular barred mixed 2 2
      LX Lenticular mixed 2 3 5
      LXR Lenticular mixed inner ring 2 2
      LXS Lenticular mixed s-shaped 3 3 6
      LXT Lenticular mixed mixed 1 1
      S Spiral 23 1 5 2 16 2 2 2 3 56
      SA Spiral non-barred 1 1 1 1 4
      SAR Spiral non-barred inner ring 1 4 2 1 3 11
      SAS Spiral non-barred s-shaped 2 3 8 15 6 23 7 3 1 2 70
      SAT Spiral non-barred mixed 1 6 13 8 28
      SB Spiral barred 9 1 3 1 3 17
      SBR Spiral barred inner ring 1 1 5 7 7 2 23
      SBS Spiral barred s-shaped 4 8 1 13 5 10 5 7 4 10 67
      SBT Spiral barred mixed 1 3 4 6 9 2 2 2 1 30
      SX Spiral mixed 1 1 1 2 5
      SXR Spiral mixed inner ring 1 2 3 5 3 14
      SXS Spiral mixed s-shaped 1 2 3 7 5 8 2 3 1 3 35
      SXT Spiral mixed mixed 1 3 3 9 19 16 11 62
      RING Ring 2 2
      RINGA Ring non-barred 4 4
      RINGB Ring barred 6 6
      I Irregular 1 10 9 20
      IB Irregular barred 14 14
      IX Irregular mixed 2 2
      P Peculiar 53 53
      Grand Total n/a 181 74 42 39 95 75 93 34 15 12 45 705

    17. Galaxy estimated size (kpc): Where a distance estimate is available based on a rough half-angle formula computation.
    18. Milky Way object size (pc): Where a distance estimate is available based on a rough half-angle forumla computation.
    19. Milky Way object structural arm association: By Milky Way Arm, based on a SEDS list and this author's algorithm from arm centerlines defined by Taylor (1993) and a Rho of 8.5 kpc after Kerr (1986).
    20. Galaxy group association after nomenclature in Tully (1988): For galaxies within 40 Mpc.
    21. Bibliographic source: For primary astrometry or unique feature.
    22. Selected comments: From source catalogues like Herschel, Barnard, Arp and Clark.
  • Stellar objects: were added to the catalogue by the following methods.
    1. Single bright stars: For single bright stars, the bright alignment stars of for the SkyScan hand-controller was used as the base list. This base list was supplemented with non-duplicative objects from the following sources:

      Table 9 - Bright Star Source Catalogues providing object entries
      CatalogueCount of catalogue objects from
      Alignment bright stars from Skyscan controller list90
      Declination drift method alignment stars on celestial equator (this author)29
      Spectral - HR Diagram stars from Kaler's Stars & Their Spectra - Supps75
      Mullaney's Celestial Harvest Carbon Stars & Misc - Supps18
      Garrison 1996 Spectral Stars with known absolute magnitudes - Supps4
    2. Double Stars and Multiple Systems: For double stars and multiple star systems, the 6th Orbit Catalogue and the UNSO Selected 2006 Double Stars from the online Astronomical Almanac were used as the base. This base list was supplemented with non-duplicative objects from the following sources:

      Table 10 - Double and Multiple Catalogues providing object entries
      CatalogueCount of catalogue objects from
      6th Orbit Catalogue155
      USNO 2006 Selected Doubles - Supp53
      Belmont Society Colorful Doubles List - Supps145
      AstroLeague Double Star Observing List - Supps51
      Mullaney's Celestial Harvest - Supps28
      Garrison 1996 Spectral Stars with known absolute magnitudes - Supps4
      Complex systems supps - brighter mag 11 w more 5 or more members (this author extracted from the CCDM)31
      Argyle's High Precision Resolution Test Stars - 090mm scopes. In Observing and Measuring Visual Double Stars. Springer.4
      Argyle's High Precision Resolution Test Stars - 150mm scopes3
      Argyle's High Precision Resolution Test Stars - 200mm scopes9
      Argyle's High Precision Resolution Test Stars - 300mm scopes13
      Argyle's High Precision Resolution Test Stars - 400mm scopes6
    3. Variable Star: For variable stars, The AAVSO master catalogue ("united.txt") filtered for selected stars with a period of less than 14 days was used as the base list. This intentionally biased catalogue variables towards short-period variables instead of the usual focal on long-period variables. This bias was incorporated into the catalogue on the assumption that beginning variable star observers would like to observe stars that will change over the course of an evening, two evenings or a week. Inspired by short-period observing, such beginners may move onto traditional long-period variable observing - where changes occur over months. The variable base list was supplemented with non-duplicative objects from the following sources:

      Table 11 - Variable Star Catalogues providing object entries
      CatalogueCatalogue objects from
      Variables - Short Period AAVSO master catalogue united.txt381
      Variables - Long Period - AAVSO Easy Variables74
      Variables - Long period - Mullaney's Celestial Harvest - Supps6
    4. Supplemental characteristic coding of stellar objects: The following supplemental characteristics were coded in the catalogue for stellar objects:
      • Catalogue cross-referencing: Catalogue ids were cross-referenced as applicable between the following catalogues: Flamsteed, Bayer, Henry Draper, Harvard Bright Star, Atkins Double Star, Catalogue of Components of Double and Multiple Systems, Washington Double Star Catalogue, 6th Orbit Catalogue and the AAVSO variable catalogue.
      • Common names
      • Stellar magnitude in the Johnson V passband: Using the Simbad record as the baseline.
      • Distribution of magnitudes of stars
        Figure 5 - Distribution of magnitudes of stars

      • Distances: Distances were obtained principally from Ochsenbein (1987) and Garrison (1996). For stars whose distance was not listed in those sources, the parallax distance was computed from the Tycho2 catalogue for those stars whose parallax was known with a 30% or greater confidence. Miscellaneous sources for distances are noted in the comments column of the main catalogue. The distribution of stellar objects with known distances is as follows:
      • Histogram of distances to stellar objects
        Figure 6 - Distribution of distances to stellar objects

      • CDS Simbad object type
      • Table 12 -Distribution of 1185 stellar types with CDS-Simbad morphology codes
        CDS-Simbad Type Total
        * 27
        ** 142
        *i* 157
        *iC 7
        *iN 2
        a2* 3
        Al* 117
        bC* 7
        Be* 5
        bL* 18
        BY* 5
        C* 19
        cC* 139
        Ce* 11
        Cl* 1
        DN* 7
        dS* 15
        EB* 12
        El* 2
        Em* 15
        Fl* 13
        FU* 1
        HXB 1
        Ir* 1
        LXB 1
        Mi* 60
        NL* 1
        No* 3
        OH* 1
        Or* 2
        pA* 1
        PM* 43
        PN 1
        Pu* 4
        RC* 4
        RI* 1
        RR* 36
        RS* 26
        RV* 2
        S* 2
        SB 2
        SB* 78
        sr* 18
        Sy* 4
        TT* 1
        V 9
        V* 118
        V*? 1
        WD* 7
        WR* 1
        WU* 19
        WV* 8
        ZZ* 4
        Grand Total 1185

      • Spectral class: from Simbad record
      • Table 13 - Distribution of 1330 stars with known MK spectral class
        Spectral Class Count
        WC 5
        WN 2
        WR 1
        O 48
        A 224
        B 201
        F 320
        G 200
        K 129
        M 111
        R 2
        N 42
        S 7
        C 23
        D? 1
        DA 9
        DB 1
        DC 1
        DO 1
        DZ 2
        Grand Total 1330
      • Atomized spectral class: The spectral class broken down into its components: The MK spectral class (OBAFGKMCNR), the MK luminosity class type (I-VI), and supplemental peculiarity letter codes. This allows filtering of stellar tours of the Hertzsprung-Russell diagram either vertically by MK spectral class or horizontally by MK luminosity type. See Figures 3.8 and 4.2 in Kaler's Stars & Their Spectra.
      • Table 14 - Distribution of 826 stars with known MK Spectral Type and MK Luminosity Class
        Spectral Ia Ib II III IV V Grand Total
        O 3 2 2 2 0 8 17
        A 2 2 2 14 22 93 135
        B 11 2 4 22 35 94 168
        C 1 0 15 0 0 0 16
        F 15 22 45 17 35 58 192
        G 12 18 7 41 9 37 124
        K 4 5 14 59 8 14 104
        M 7 1 5 48 0 8 69
        N 1 0 0 0 0 0 1
        Grand Total 56 52 94 203 109 312 826
      • Computed color index: The Simbad record B-V value
      • For double stars: The CCDM was used as the base source for binary and multiple star system characteristics:
      • Variable star period and type: In days, where it is listed in the source catalogue:
      • Distribution of periods of 452 days
        Figure 8 - Distribution of periods (days) of 452 variable stars

        Table 18 - Distribution of 455 Variables with AAVSO type codes
        Class Description Count
        CEP Cepheid type pulsating variable 23
        DCEP Delta Cepheids 134
        DSCT delta Sct type pulsating variable 13
        E eclipsing binary system 163
        IS rapid irregular variable, no apparent connection with diffuse nebulosity 2
        L irregular 1
        LB slow, irregular late spectral type variables 2
        M Mira type variables 53
        N nova type eruptive systems 1
        RCB R CrB type eruptive variable 4
        RR RR Lyr type pulsating variable 25
        RS RS CVn type eruptive variable 4
        RV RV Tau type pulsating variable 1
        SR semiregular pulsating variable 12
        SXPHE SX Phe type pulsating variable 6
        UG U Gem type eruptive variable (dwarf nova) 3
        UV UV Cet type eruptive variable; flare star 3
        X x-ray source, close binary system with one component a hot, compact object 2
        Z Cam Z Cam type nova type eruptive systems 3
        Total Grand total 455
      • Extra-solar planets: Count = 8. Where a star had been previously listed in the catalogue by the above process, and the star is listed in the California and Carnegie Planet Search Table of "Masses and Orbital Characteristics of Extrasolar Planets", the Comments field in the catalogue was tagged with the text "extrasolar planet".
      • Milky Way object structural arm association: By Milky Way Arm, based this author's algorithm from arm centerlines defined by Taylor (1993) and a Rho of 8.5 kpc after Kerr (1986).
      • Bibliographic source: For primary astrometry or unique feature.
  • Region markers: The following regions and fiducial markers on the celestial sphere were included in the catalogue:
    1. Useful regions markers: Useful regions were assembled from various sources:

      Table 19 - Useful regions markers included in catalogue
      CatalogueCount of catalogue objects from
      Limiting Magnitude Areas - Int'l Meteor Org.46
      Photometry - Landolt standard star fields24
      Asterisms per SEDS with supps50
      Meteor shower radiants - Int'l Meteor Org. - Meteor Shower Calendar 200651
    2. Fiducial points: Fiducial points were for the most part computed or obtained from online coordinate conversion calculators:

      Table 20 - Fiducial points included in catalogue
      CatalogueCount of catalogue objects from
      Parapegma - Ecliptic marker - Greek regular 30 deg constellations12
      Parapegma - Galactic plane IAU constellations - chart take-offs by this author18
      Structure - Ecliptic plane marker 30 deg - computed this author2
      Structure - Galactic plane marker 30 deg - computed this author17
      Structure - Supergalactic plane marker 30 deg - after the NEDS's coordinate converter14
    3. Milky Way Structure points: Milky Way structural points were constructed from the following sources:

      Table 21 - Milky Way Structure - misc points of interest
      Orion Arm spinward anti-spinward apexes - after Walkey (1946)2
      Galactic spiral arms - distances - after Taylor (1993)7
      Gould's Belt after Grenier (2004) 5
      Misc. OB Associations within 1 kpc - after Dame (1987)10
      Olano's Ring - Associated Molecular Clouds - after Olano (2001)3
      Olano's Ring - Associated OB Associations - after Olano (2001)14

    This process yielded approximately 3,100 object entries.

    Download component spreadsheets

    All spreadsheets are in MS-Excel (2003). Right-click link to download component.

    Main catalogue spreadsheet ObsSpdht.xls is the primary component. It must be open on the desktop when all other spreadsheets are opened. The other component spreadsheets are subsidiary and dependent-linked to primary spreadsheet ObsSpdht.xls.

    User guide

    It is assumed that the user has a basic working knowledge of Microsoft Excel and Excel's drill-down capabilities via the "Data filter" menu option.

    The spreadsheet uses Visual Basic for Applications (VBA) code to compute numerous values. You will need to respond "Enable macros" to the standard Excel security prompt to update the spreadsheet.

    Only enter data in blue-background cells. Use notes by component spreadsheet and worksheet tab follow:

    Milky Way Structure and Supergalactic Structure - Index with Internet Casebook Reader

    Learn about history of astronomy, the structure of the Milky Way, how astronomers discovered the structure of the Milky Way, and the structure of the supergalactic universe by reading astronomical journal articles, websites and some hard copy books. Get a sense of how astronomical scientific knowledge is incrementally discovered through the scientific process. Although most of the journal articles contain higher level math that is beyond the average amateur, many journal articles contain narrative conclusions and figures that are within the range of most amateur readers. NASA ADS Services redistributes - for single download, personal reading - astronomical journal articles - many of which are subject to copyright protection. The Reader-Bibliography is an index to landmark journal articles and books and other resources with external content links to the NASA ADS and other websites. To learn more about Milky Way structure and astronomy history, start reading here . . .

    Legal disclaimers

    No implied warranty

    The content of this website and the data contained herein are distributed without charge in the hope that it will be useful, but without any warranty, including without any implied warranty of merchantability or fitness for a particular purpose, to the extent permitted by applicable law. The content of this website and spreadsheet data contained herein are distributed "as is" without warranty of any kind, either expressed or implied. The entire risk as to the quality and performance of the software and data are with you, including any general, special, incidental or consequential damages arising out of the use or inability to use the website and spreadsheet data contained herein.

    Amateur content

    This website contains amateur astronomer developed materials and is not suitable for citation as an authoritative source.

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    No copyright asserted

    No copyright is asserted to any original content materials developed and included by this author in this website and the same are released to the public domain. No copyright is asserted as to any scientific fact recited herein.


    Download a local copy of this site.

    It is the nature of the internet that information contained on it is temporary. This website was developed for the enjoyment of the amateur astronomical community and as an aid for astronomy clubs, amateurs and secondary school educators. I encourage students and other amateurs to freely download, store and/or redistribute this website.

    Revision and bug history

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    Centre de Données astronomiques de Strasbourg - Simbad: This project has made use of the SIMBAD database, operated at CDS, Strasbourg, France.

    Centre de Données astronomiques de Strasbourg - Catalogue Service: This project has made use of numerous catalogues redistributed through the CDS Astronomer's Catalogue Service, operated at CDS, Strasbourg, France. Catalogues that were utilized are listed in Bibliography and the Distance Bibliography. The use of those sources are by this reference is acknowledged and appreciated.

    NASA Astrophysics Data System/Computation Facility at the Harvard-Smithsonian Center for Astrophysics - NASA ADS Abstract Services: This project has made use of NASA's Astrophysics Data System.

    Nigel Henbest and Heather Couper: This project was inspired by the N. Henbest & H. Couper's 1994 book The Guide to the Galaxy. Cambridge Univ. Press. (

    Salt Lake Astronomical Society: At the time this site author was created, the author was a member of the Salt Lake Astronomical Society (SLAS). While SLAS neither participated in nor endorses this project, the use of SLAS's 16 inch Ealing Telescope at SLAS's Harmon's Observatory in the Stansbury Park Observatory Complex (SPOC) at Tooele, Utah remains a continuing inspiration, which is acknowledged here.

    voluntary donation request

    Make a voluntary donation using PayPal:

    This site is not an alpha version of a software product intended for future commercial distribution. These catalogue will not be distributed commercially.

    Like many hobbies, amateur astronomy relies on the goodwill and fraternal desire of its participants to freely share without charge. This author remains committed to that standard of conduct in the amateur astronomical community. But in this instance, the many nights and weekends over a five month period needed to develop the underlying spreadsheet database, to review professional astronomy journals for the reasonably current and accurate distance information, and to develop VRML rendering scripts, ethically appeared to justify an entirely voluntary donation request.

    Prepared by: K. Fisher 7/2006