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



 
 
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  #1  
Old February 26th 06, 01:08 AM posted to sci.astro.amateur
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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

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  #2  
Old February 28th 06, 09:40 PM posted to sci.astro.amateur
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Default 145 CMa - the Winter Albireo - a colorful after-work winter double Feb-Mar

canopus56 wrote:
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. snip


Offline, a correspondent "Mike" asked:
What catalogs do 145 CMa / HD 056577 appear in?


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.

From the perspective of non-double star observing amateurs - the

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.

This triggered an inquiry to the Starry Night
support forum (figured I was doing something wrong),
and the response I got was that there are hundreds
of catalogs and the developers could not
use them all, and they agreed that these
numbers are not in the SN database.


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.

From my infrequent use of Starry Night (and hazy recollections my

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  
Old March 1st 06, 05:51 AM posted to sci.astro.amateur
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Default 145 CMa - the Winter Albireo - a colorful after-work winter doubleFeb-Mar

canopus56 posted:

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


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
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  
Old March 1st 06, 08:50 PM posted to sci.astro.amateur
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Default 145 CMa - the Winter Albireo - a colorful after-work winter double Feb-Mar

David Knisely wrote:
snip
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. 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  
Old March 5th 06, 12:43 PM posted to sci.astro.amateur
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Default 145 CMa - the Winter Albireo - a colorful after-work winter double Feb-Mar

canopus56 wrote in message:
145 CMa (HD056577) - the Winter Albireo - is at it's most favorable low
declination position (J071636.00-231912.0) for 41N op's.
snip


Canopus56,

THANK YOU!! Neither I nor any of the members & visitors attending our
public viewing night at the club's observatory had ever seen this beautiful
double. Miraculously, we had a completely clear, but cold, night in NE Ohio
and took advantage of it. If it weren't for your post, we certainly
wouldn't have seen it last night - or perhaps ever. Your subsequent post
listing the HD number was also a great service, and much appreciated.

Thanks again.

Clear Dark Steady Skies,
Dave Jessie


  #6  
Old March 8th 06, 09:29 PM posted to sci.astro.amateur
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Default 145 CMa - the Winter Albireo - a colorful after-work winter double Feb-Mar


"Dave Jessie" wrote in message
...
canopus56 wrote in message:
145 CMa (HD056577) - the Winter Albireo - is at it's most favorable low
declination position (J071636.00-231912.0) for 41N op's.
snip


Canopus56,

THANK YOU!! Neither I nor any of the members & visitors attending our
public viewing night at the club's observatory had ever seen this
beautiful double. Miraculously, we had a completely clear, but cold,
night in NE Ohio and took advantage of it. If it weren't for your post,
we certainly wouldn't have seen it last night - or perhaps ever. Your
subsequent post listing the HD number was also a great service, and much
appreciated.


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  
Old March 8th 06, 11:03 PM posted to sci.astro.amateur
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Default 145 CMa - the Winter Albireo - a colorful after-work winter doubleFeb-Mar

Stephn Paul posted:

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


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
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  
Old March 8th 06, 11:32 PM posted to sci.astro.amateur
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Posts: n/a
Default 145 CMa - the Winter Albireo - a colorful after-work winter doubleFeb-Mar

David Knisely wrote:
Stephn Paul posted:

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



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)

Clear skies to you.



Hi

Thanx from me too



--
AM

http://sctuser.home.comcast.net

CentOS 4.2 KDE 3.3
  #9  
Old March 9th 06, 03:16 PM posted to sci.astro.amateur
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Posts: n/a
Default 145 CMa - the Winter Albireo - a colorful after-work winter double Feb-Mar


"David Knisely" wrote in message
...
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


Excellent!

Thanks David.

-Stephen

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