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  1. #1
    canopus56's Avatar
    canopus56 Guest

    Default 145 CMa - the Winter Albireo - a colorful after-work winter double Feb-Mar



    145 CMa (HD056577) - the Winter Albireo - is at it's most favorable low
    declination position (J071636.00-231912.0) for 41N op's. 145 CMa is
    visible in small refractors after sunset from urban light polluted
    skies. The Belmont Society Colorful Double Star List describes pi Gem
    as "orange/blue-green" while Mullaney's _Celestial Harvest_ gives this
    double an effusive recommendaton. The primary of this colorful
    multiple is a v4.8 K4III star at an estimated distance of 536 parsecs.
    The discover designation - HJ 3945 - attributes first recorded sighting
    to William Herschel. At 536 parsecs and G236.50-05.22, this double
    sits west of Canis Major "down-wind" in the Orion Arm from Sol, in a
    area rich in small open clusters.

    Current (Epoch 2000) CCDM data on 145 CMa (CCDM 07166-2319) is:

    C PA sep mag
    A 4.8
    B 055 26.6 6.8

    145 CMa is about 3 degs east of omi2 CMa. A courtesy star hopping
    finder chart is provided at:
    http://members.csolutions.net/fisher...45StarHops.jpg

    145 CMa current is low on the horizon from 41N ops - at about only 20
    degrees in altitude at sunset. 145 CMa can be star-hopped or
    right-angle swept by starting at omi2 CMa. From my light polluted v3.0
    urban skies, I began at del CMa and swept north about 3 degs to omi2
    CMa. omi2 CMa was just barely naked-eye visible in the light pollution.
    Due to light pollution, there were really not any good landmarks to
    star hop to 145 CMa. Finding this double is a bit challenging in light
    polluted skies. Since 145 CMa is a direct east declination sweep from
    omi2 CMa, I simply used the lowest feasible magnification, with the
    largest TFOV, about 1 deg in this case - and then counted about 3 1/2
    ep views east of omi2 CMa until I saw a small double that looked like
    145's namesake - Albireo.

    In a small alt-az 60mm refractor under urban Bortle class 8 mag 3.0
    light-polluted urban skies at 22x, 145 CMa lives up to its namesake as
    the Winter Albireo. It is a nice, distinct, intense blue-gold pair
    about 22" apart. But unlike it's summer namesake, the Winter Albireo
    is over 500 parsecs distant, while the "real" Albireo is about 125
    parsecs away. On increasing magnification to about 78x, the Winter
    Albireo the colors fade and somewhat dim in a small refractor. In
    contrast, the bet Cyg double retains is golden-jewel crispness under
    higher magnification.

    All-in-all, this was a nice 15-20 minutes of easy after-work
    beer-in-hand viewing at 41N.

    The Belmont Society Colorful Double Star list can be found at:
    http://www.belmontnc.4dw.net/dblstrs.htm

    - Canopus56


  2. #2
    canopus56's Avatar
    canopus56 Guest

    Default 145 CMa - the Winter Albireo - a colorful after-work winter double Feb-Mar

    canopus56 wrote:

    Offline, a correspondent "Mike" asked:

    My apologies if the informal designation of Herschel 3945, the Winter
    Albireo, as 145 CMa, caused more heat than light. I had always learned
    this binary as "145 CMa," I believe it was from Harrington's TUBA. You
    are correct to critize the informal desigation of this binary as 145
    CMa. As to an authoritative cite, the short answer is that the "A"
    component (HD56577, HR2764) are cross-referenced in Kostjuk (2002)
    HD-DM-GC-HR-HIP-Bayer-Flamsteed Cross Index CDS IV/27 as:

    HD56577
    HR2764
    CD-23 5189
    HIP35210
    ---- 145 CMa ------
    http://cdsweb.u-strasbg.fr/viz-bin/Cat?IV/27

    One simple method establishing an association between Component A of
    Herschel 3945 and 145 CMa, is to in "145 CMa" into the CDS Simbad
    database.
    http://simbad.u-strasbg.fr/sim-fid.pl

    Simbad returns a number of cross-references for 145 CMa, including:

    * 145 CMa
    ADS 5951 A
    CCDM J07166-2319A
    HD 56577
    HR 2764
    SAO 173349
    SKY# 13175

    Feeding in the HD designation for the B Component of Herschel 3945 -
    HD56578 - gives:

    ** HJ 3945B
    ADS 5951 B
    CCDM J07166-2319B
    CD-23 5192
    HIC 35213
    HIP 35213
    SKY# 13177

    As to how CDS Simbad associates 145 CMa with the A Component of
    Herschel 3945, a more detailed list of catalogue links between
    Component A and 145 CMa is appended.

    Again, you are correct to critize the informal designation of this
    binary as 145 CMa. A better, and admittedly less confusing
    designation, would have been it's formal discoverer designation -
    Herschel 3945.

    intended target of the post - Herschel 3945 is the designation used in
    the Belmont Society Colorful Doubles List and is the most returned
    designation from a web engine search on the phrase "Winter Albireo."
    Personally, I can never seem to remember "HJ3945," while the Flamsteed
    designation "145 CMa" is more easily remembered.

    In general, the appropriate method to refer to multiple star systems is
    by their CCDM (Catalogue of the Components of Double and Multiple
    Stars) designation, or their discover designation, e.g. HJ3945,
    **STF761.

    For informal observing of bright doubles, I prefer to simply remember
    the Flamsteed or Bayer designation of the star, e.g. sig Ori, pi Gem,
    zet Per, or 145 CMa. That is technically improper, but it is easier to
    use when pointing the telescope.


    The software I use is Cartes du Ciel which also does not return 145
    CMa, but does position fix on "HD56577". In my defense of the informal
    designation use, Cartes du Ciel, as installed out-of-the-box, does not
    return Herschel 3945 either - at least unless specialty supplemental
    catalogues are installed. I suspect that Starry Night will not return
    "Herschel 3945" either.

    As a general note on using various software packages, it is not unusual
    to have various software package not return positions to the most
    commonly used catalogue name designations. Alot of time is spent
    "decoding" designations and finding the one that your software will
    recognize. Typically, users install add-on catalogues and indices for
    their area of interest, e.g. DSOs or double stars.

    difficulties in using it), for example, out-of-the-box, Starry Night
    would not find a number of galaxies by NGC number - you had to decode
    and find the "PGC" Principal Galaxy Catalogue cross-reference number.

    In conclusion, you are not doing anything wrong. Failed
    cross-references within a software package is a common problem in the
    hobby. For DSOs and stars, I find the CDS Simbad database and
    invaluable tool in that regard:

    CDS Simbad in Strasbourg, France
    http://simbad.u-strasbg.fr/sim-fid.pl

    CDS Simbad mirrored at Harvard, U.S.
    http://simbad.harvard.edu/Simbad

    For bright stars, Kostjuk (2002) catalogue
    ("HD-DM-GC-HR-HIP-Bayer-Flamsteed Cross Index") is an invaluable
    resource that I frequently use. I have downloaded a copy of the entire
    catalogue as an HTML document using the Simbad catalogue service.
    http://cdsweb.u-strasbg.fr/viz-bin/Cat?IV/27

    Then I imported a local copy of the catalogue as an HTML document into
    Excel and cleaned it up.

    In conclusion, it is unfortunate that Starry Night and/or Cartes du
    Ciel do not quickly return a position fix on common references to this
    beautiful winter binary. It is a colorful binary that is often
    overlooked by beginners. Hopefully, your web conversations will spur
    the developers to correct this minor omission.

    - Regards, Canopus56

    Addendum

    ===============
    Catalogue linking Herschel 3945 to 145 CMa
    ===============

    ----------------
    The CCDM links CCDM J07166-2319A to HJ3945, the Winter Albireo's most
    formal-discover designation, to:
    CCDMJ07166-2319B and HIC35213 and the A component - HIC35210.
    http://cdsweb.u-strasbg.fr/viz-bin/Cat?I/274

    ----------------
    Dommanget, J. The visual double stars observed by the Hipparcos
    satellite. <Astron. Astrophys. 363, 991 (2000)>
    links HJ3945 to:
    HIP35210
    CCDM07166-2319A

    HIP35213
    CCDM07166-2319B
    http://cdsweb.u-strasbg.fr/viz-bin/Cat?I/260

    ----------------
    The Hipparcos Input Catalogue, Version 2 (1993) links HIP35210 and
    HIP3523 provides the following cross-references:
    HIC35210
    BD-23 117
    CD -23 5189
    HD56577
    SAO173349

    HIC35213
    BD -23 118
    CD -23 5192
    CPD-23 2015
    HD56578
    SAO173353
    http://cdsweb.u-strasbg.fr/viz-bin/Cat?I/196

    ----------------
    The Yale Bright Star Catalogue, 5th Revised Ed.(Hoffleit+, 1991)
    catalogue cross-references HD56577 to:
    HR2764
    ADS5951
    http://cdsweb.u-strasbg.fr/viz-bin/Cat?V/50

    ----------------
    Kostjuk (2002) HD-DM-GC-HR-HIP-Bayer-Flamsteed Cross Index CDS IV/27
    cross-references HR2764 and HD56577 to 145 CMa, as discussed above.
    http://cdsweb.u-strasbg.fr/viz-bin/Cat?IV/27


  3. #3
    David Knisely's Avatar
    David Knisely Guest

    Default 145 CMa - the Winter Albireo - a colorful after-work winter doubleFeb-Mar

    canopus56 posted:


    You have no reason to apologize to anyone over this. While h3956 is one
    of the more common designations for this colorful double star (along
    with ADS 5951), I have seen it referred to as "145 CMA" from time to
    time from a variety of sources. Probably the earliest published work I
    have seen that designation in was David Eicher's book DEEP-SKY OBSERVING
    WITH SMALL TELESCOPES (1989), so it goes back for a while. I ran into
    it again when testing my NexStar telescope, as it had 145 CMa listed in
    its double star database. Whether it is actually an original Flamsteed
    number is uncertain, as I understand that the highest Flamsteed number
    within any constellation is 140 (140 Tauri). In any case, the 145 CMa
    designation is somewhat valuable here, as it it easier to remember than
    h3945 and tells you instantly what constellation it is in. You also did
    a valuable service by bringing this "winter Albireo" to the attention of
    people who might not have hear of it. Clear skies to you.
    --
    David W. Knisely KA0CZC@navix.net
    Prairie Astronomy Club: http://www.prairieastronomyclub.org
    Hyde Memorial Observatory: http://www.hydeobservatory.info/

    **********************************************
    * Attend the 13th Annual NEBRASKA STAR PARTY *
    * July 23-28, 2006, Merritt Reservoir *
    * http://www.NebraskaStarParty.org *
    **********************************************

  4. #4
    canopus56's Avatar
    canopus56 Guest

    Default 145 CMa - the Winter Albireo - a colorful after-work winter double Feb-Mar

    David Knisely wrote:
    <snip>

    Thanks David -with the proviso that 145 CMa does not seem to come up
    in commonly used software packages and beginners that should try the HR
    or HD designates in their software search boxes:

    145 CMa = HD56577 = HR2764

    - Canopus56


  5. #5
    canopus56's Avatar
    canopus56 Guest

    Default 145 CMa - the Winter Albireo - a colorful after-work winter double Feb-Mar

    Dave Jessie wrote:

    Glad to be of help. - C


  6. #6
    Stephen Paul's Avatar
    Stephen Paul Guest

    Default 145 CMa - the Winter Albireo - a colorful after-work winter double Feb-Mar


    "Dave Jessie" <DJesSHOESsie@neo.rr.com> wrote in message
    news:J1BOf.1125$9I5.545@tornado.ohiordc.rr.com...

    Indeed. I took advantage of the opportunity and the information as well. I
    even created my own Double Star list in SkyTools and made this the first
    entry. These are the kinds of reports I want to see more of on SAA.

    What the heck should we be looking at, that's off the beaten path, on an
    obscure or even non-existent list?

    Keep these coming! I need to fill up my Double Star list (and Galaxy, Open
    Cluster, PN, ...etc.).

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  7. #7
    David Knisely's Avatar
    David Knisely Guest

    Default 145 CMa - the Winter Albireo - a colorful after-work winter doubleFeb-Mar

    Stephn Paul posted:


    Well, I don't know about obscure, but here are some of my most favorite
    color-contrasting double stars:

    COMMON DOUBLE STARS WITH SIGNIFICANT COLOR CONTRAST
    (positions, separations, and position angles for 2000)

    LEGEND: R.A. = Right Ascension (2000.0) Dec. = Declination
    mag. = apparent visual magnitude sp. = spectral type
    Sep. = separation (in arc seconds) P.A. = position angle
    ************************************************** ******************

    Eta Cassiopeiae, R.A. 0h 49.10m Dec. +57d 49.0'
    Primary: mag. 3.4, sp. G0V, Secondary: mag. 7.5, sp. dM0
    Sep. 12.8" arc, P.A. 317 deg. (period: 480 years)
    Colors seen in 10 inch: Off-white and faint reddish-orange.

    ALMACH (Gamma And.), R.A. 2h 3.90m Dec. +42d 19.8'
    Primary: mag. 2.2 sp. K3III, Secondary: mag. 4.8 sp. B8V
    Sep. 9.8" arc, P.A. 64 deg. (mag. 6.3 companion of Gamma-B at 0.4" arc,
    p.a. 103 deg.).
    Colors seen in 10 inch: Yellow (Gold) and light blue.

    32 Eridani, R.A. 3h 54.29m Dec. -2d 57.3'
    Primary: mag. 4.5, sp. G8III, Secondary: mag. 6.1, sp. A2V
    Sep. 6.9" arc, P.A. 348 deg.
    Colors seen in 10 inch: Yellow and pale blue.

    38 Geminorum (STF 982), R.A. 6h 54.64m Dec. +13d 10.7'
    Primary: mag. 4.7, sp. F0V, Secondary: mag. 7.7, sp. ?
    Sep. 7.1" arc, P.A. 144 deg.
    Colors seen in 10 inch: White and faint orangish.

    h3945 (ADS 5951, CMa), R.A. 7h 16.61m Dec. -23d 18.9'
    Primary: mag. 4.8 sp. K4III, Secondary: mag. 6.8, sp. F0
    Sep. 26.6" arc, P.A. 55 deg.
    Colors seen in 10 inch: Orange and bluish-white.
    "The Winter Albireo"

    Iota Cancri, R.A. 8h 46.70m Dec. +28d 45.6'
    Primary: mag. 4.0 sp. G8II, Secondary: mag. 6.6 sp. A3V
    Sep. 30.5" arc, P.A. 307 deg.
    Colors seen in 10 inch: Light yellow and pale blue.

    Tau Leonis, R.A. 11h 27.94m Dec. +2d 51.3'
    Primary: mag. 4.9 sp. G8II, Secondary: mag. 7.4 sp. ?
    Sep. 89.7' arc, P.A. 180 deg.
    Colors seen in 10 inch: Yellow and pale bluish-white.
    *nice low power pair with double 83 Leonis 20' at P.A. 298 deg.

    2 Canum Venaticorum, R.A. 12h 16.13m Dec. +40d 39.6'
    Primary: mag. 5.7, sp. M1III, Secondary: mag. 8.7, sp. F7V
    Sep. 11.3" arc, P.A. 260 deg (2003).
    Colors seen in 10 inch: Yellowish-orange and pale bluish.

    24 Comae Berenices, R.A. 12h 35.13m Dec. +18d 22.6'
    Primary: mag. 5.0 sp. K2III, Secondary: mag. 6.6 sp. A7V
    Sep. 20.3" arc, P.A. 271 deg.
    Colors seen in 10 inch: Yellow and pale blue.

    Cor Caroli (Alpha CVn), R.A. 12h 56.00m Dec. +38d 19.1'
    Primary: mag. 2.9 sp. A0spe, Secondary: mag. 5.6, sp. F0V
    Sep. 18.8" arc, P.A. 230 deg.
    Colors seen in 10 inch: Bluish-white and off-white (cream).

    Izar (Epsilon Bootis), R.A. 14h 44.99m Dec. +27d 4.5'
    Primary: mag. 2.4 sp. K0II, Secondary: mag. 5.1, sp. A2V
    Sep. 2.8" arc P.A. 339 deg.
    Colors seen in 10 inch: Yellow and light blue.

    Xi Bootis, R.A. 14h 51.39m Dec. +19d 6.0'
    Primary: mag. 4.5, sp. G8V, Secondary: mag. 6.8, sp. K5V
    Sep. 6.8" arc P.A. 320 deg.
    Colors seen in 10 inch: Pale yellowish white and orange.

    Antares (Alpha Sco). R.A. 16h 29.41m Dec. -26d 25.9'
    Primary: mag. 1.0v sp. M1I, Secondary: mag. 5.4 sp. B4
    Sep. 2.6" arc P.A. 274 deg.
    Colors seen in 10 inch: Orange and light blue.

    Ras Algethi (Alpha Her) R.A. 17h 14.65m Dec. +14d 23.4'
    Primary: mag. 3.2v sp. M5II Secondary: mag. 5.4, sp. F2/G3
    Sep. 4.6" arc P.A. 104 deg.
    Colors seen in 10 inch: Reddish-orange and pale bluish-white.

    Omicron Ophiuchi, R.A. 17h 18.00m Dec. -24d 17.2'
    Primary: mag. 5.1, sp. K.. Secondary: mag. 6.6, sp. ?
    Sep. 10.3" arc, P.A. 355 deg.
    Colors seen in 10 inch: Yellow and pale blue.

    SHJ 282 (ADS 11834, Lyra), R.A. 18h 54.90m Dec. +33d 58.0'
    Primary: mag. 6.1, sp. G8 Secondary: mag. 7.7, sp. A1
    Sep. 45.4" arc P.A. 350 deg.
    Colors seen in 10 inch: Yellowish-white and bluish-white.

    Albireo (Beta Cyg) 19h 30.72m Dec. +27d 57.6'
    Primary: mag. 3.1 sp. K3II Secondary: mag. 5.1 sp. B8V
    Sep. 34.3" arc P.A. 54 deg.
    Colors seen in 10 inch: Yellow and light blue.

    ADS 12900 (Cyg). 19h 45.86m Dec. +35d 0.77'
    Primary: mag. 6.1 sp. K2? Secondary: mag. 8.6 sp. A2V
    Sep. 37.5" arc P.A. 25 deg.
    Colors seen in 10 inch: Yellow and blue.

    Gamma Delphini, R.A. 20h 46.73m Dec. +16 deg. 7.8'
    Primary: mag. 4.2 sp. G5V, Secondary: mag. 5.2 sp. F8V.
    Sep. 9.6" arc P.A. 268 deg.
    Colors seen in 10 inch: Yellowish and white (hint of blue)?

    Delta Cephei R.A. 22h 29.20m Dec. +58d 25'
    Prmary: mag. 4.07 (variable) sp. F5-G3 Secondary: mag. 6.27 sp. B7
    Sep. 40.8" arc P.A. 191 deg.
    Colors seen in 10 inch: Yellowish-white and light blue.

    Clear skies to you.
    --
    David W. Knisely KA0CZC@navix.net
    Prairie Astronomy Club: http://www.prairieastronomyclub.org
    Hyde Memorial Observatory: http://www.hydeobservatory.info/

    **********************************************
    * Attend the 13th Annual NEBRASKA STAR PARTY *
    * July 23-28, 2006, Merritt Reservoir *
    * http://www.NebraskaStarParty.org *
    **********************************************

  8. #8
    AM's Avatar
    AM Guest

    Default 145 CMa - the Winter Albireo - a colorful after-work winter doubleFeb-Mar

    David Knisely wrote:


    Hi

    Thanx from me too



    --
    AM

    http://sctuser.home.comcast.net

    CentOS 4.2 KDE 3.3

  9. #9
    Stephen Paul's Avatar
    Stephen Paul Guest

    Default 145 CMa - the Winter Albireo - a colorful after-work winter double Feb-Mar


    "David Knisely" <KA0CZC@navix.net> wrote in message
    news:aa2e4$440f62bf$d8603d07$17077@ALLTEL.NET...

    Excellent!

    Thanks David.

    -Stephen

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