star clusters

Abbreviations- M, million; k, thousand; ly, light years; Temp, temperature; RH, relative humidity; DP, dew point; NA, not applicable; FOV- field of view; au- astronomical units (1 au = distance from Sun to Earth or 93 million miles)

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NGC 5466 is a globular cluster in the constellation Bootes ~52 kly from Earth.  It is unusual in that it contains metal-poor stars.
	Object	NGC 5466
	Distance	52 kly
	Constellation	Bootes
	Link	NGC 5466
	Date	March 25 - 30, 2017 (Tucson, AZ)
	Conditions	Clear, Temp- ~55 F, RH- ~30%, DP- ~35 F
	Moon	Waning gibbous to waxing gibbous
	Seeing	2.0 - 3.0 arc-sec
	Telescope	RCOS 12.5" Ritchey-Chretien @ f9
	CCD camera	SBIG STL11000M
	Luminance	24 x 10 min; 1 x 1
	Red	6 x 10 min; 2 x 2
	Green	6 x 10 min; 2 x 2
	Blue	6 x 10 min; 2 x 2
	HA	NA
	FOV (width)	43.3 arc-min or 656 LY
	Click here to see a larger version.

M2, also called NGC 7089, is a globular cluster in the constellation Aquarius ~33 kly from Earth.  It is comprised of approximately 150,000 stars including red and yellow giants and 21 variable stars.  It is estimated to be ~13 billion years old and is one of the oldest globular clusters in the Milky Way.
	Object	M2
	Distance	33 kly
	Constellation	Aquarius
	Link	M2
	Date	November 08 - 10, 2014 (Tucson, AZ)
	Conditions	Clear, Temp- ~65 F, RH- ~30%, DP- ~35 F
	Moon	Waxing gibbous
	Seeing	2.0 - 3.0 arc-sec
	Telescope	RCOS 12.5" Ritchey-Chretien @ f9
	CCD camera	SBIG STL11000M
	Luminance	45 x 5 min; 1 x 1
	Red	15 x 5 min; 2 x 2
	Green	15 x 5 min; 2 x 2
	Blue	15 x 5 min; 2 x 2
	HA	NA
	FOV (width)	43.3 arc-min or 416 ly
	Click here to see a larger version.

 

M15, also called NGC 7078, is a globular cluster in the constellation Pegasus ~33 kly from Earth.  It is comprised of over 100,000 stars including 112 variable stars, 8 pulsars, and one double neutron star system.  It is estimated to be ~12 billion years old.
	Object	M15
	Distance	33 kly
	Constellation	Pegasus
	Link	M15
	Date	November 08, 2013 (Tucson, AZ)
	Conditions	Clear, Temp- ~65 F, RH- ~30%, DP- ~35 F
	Moon	Waxing gibbous
	Seeing	2.0 - 3.0 arc-sec
	Telescope	RCOS 12.5" Ritchey-Chretien @ f9
	CCD camera	SBIG STL11000M
	Luminance	15 x 5 min; 1 x 1
	Red	15 x 5 min; 2 x 2
	Green	15 x 5 min; 2 x 2
	Blue	15 x 5 min; 2 x 2
	HA	NA
	FOV (width)	43.3 arc-min or 416 ly
	Click here to see a larger version.

 

NGC 457, also called the ET cluster, is an open cluster in the constellation Cassiopeia 7.9 kly from Earth.  It is comprised of approximately 150 stars.  Many of them are B class stars meaning they are hot and blue.  A few redder stars can also be seen.  NGC 457 has an estimated age of 21 million years.
	Object	NGC 457
	Distance	7.9 kly
	Constellation	Cassiopeia
	Link	NGC 457
	Date	November 14, 2013 (Tucson, AZ)
	Conditions	Clear, Temp- 65 F, RH- 34%, DP- 36 F
	Moon	Waxing gibbous
	Seeing	2.0 - 3.0 arc-sec
	Telescope	RCOS 12.5" Ritchey-Chretien @ f9
	CCD camera	SBIG STL11000M
	Luminance	12 x 2 min; 1 x 1
	Red	12 x 2 min; 2 x 2
	Green	12 x 2 min; 2 x 2
	Blue	12 x 2 min; 2 x 2
	HA	NA
	FOV (width)	43.3 arc-min or 100 ly
	Click here to see a larger version.

 

NGC 663 is an open cluster in the constellation Cassiopeia 6.8 kly from Earth.  It is comprised of over 400 stars.  Many of them are B class stars meaning they are hot and blue.  Some of these B class stars are nearing the end of their main sequence lifespan.  A few redder stars can also be seen.  Click here to see a zoomed in field of view.
	Object	NGC 663
	Distance	6.8 kly
	Constellation	Cassiopeia
	Link	NGC 663
	Date	November 13, 2012 (Tucson, AZ)
	Conditions	Clear, Temp- 60 F, RH- 15%, DP- 12 F
	Moon	New moon
	Seeing	2.0 - 3.0 arc-sec
	Telescope	RCOS 12.5" Ritchey-Chretien @ f9
	CCD camera	SBIG STL11000M
	Luminance	12 x 5 min; 1 x 1
	Red	6 x 5 min; 2 x 2
	Green	6 x 5 min; 2 x 2
	Blue	6 x 5 min; 2 x 2
	HA	NA
	FOV (width)	43.3 arc-min or 86.4 ly
	Click here to see a larger version.

 

M44, also known as the Beehive cluster, is an open cluster in the constellation Cancer 577 ly from Earth.  It is comprised of over 350 stars.  Many of them are B class stars meaning they are hot and blue.  The cluster also contains red giants and white dwarfs.  It is about 600 million years old.  Galileo was first to observe it with a telescope in 1609.
	Object	M44 (Beehive Cluster)
	Distance	577 ly
	Constellation	Cancer
	Link	Messier 44
	Date	January 29, 2012 (Tucson, AZ)
	Conditions	Clear, Temp- 54 F, RH- 37%, DP- 28 F
	Moon	Waxing crescent
	Seeing	2.0 - 3.0 arc-sec
	Telescope	RCOS 12.5" Ritchey-Chretien @ f9
	CCD camera	SBIG STL11000M
	Luminance	12 x 5 min; 1 x 1
	Red	6 x 5 min; 2 x 2
	Green	6 x 5 min; 2 x 2
	Blue	6 x 5 min; 2 x 2
	HA	NA
	FOV (width)	43.3 arc-min or 7.3 ly
	Click here to see a larger version.

 

3C273 is a quasar 2 billion light years from Earth.  Quasars look like stars but are really super massive black holes at the center of active galaxies. 3C273 has a luminosity one trillion times that of our sun (or 100 X that of our entire Milky Way galaxy). You can see a faint jet of gas extending to the left of 3C273.
	Object	3C273
	Distance	2,000 Mly (2 billion light years)
	Constellation	Andromeda
	Link	3C273
	Date	June 06, 2008 (West Bloomfield, MI)
	Conditions	Clear, Temp- 81 F, RH- 10%, DP- 23 F
	Moon	New moon
	Seeing	2.5 - 3.0 arc-sec
	Telescope	RCOS 12.5" Ritchey-Chretien @ f9
	CCD camera	SBIG ST10XME
	Luminance	30 min; 1 x 1
	Red	NA
	Green	NA
	Blue	NA
	HA	NA
	FOV (width)	21.8 arc-min or 12.7 Mly

 

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