White dwarfs and YOU
Would the plural of "white dwarf" be "white dwarves"? To the best of my knowledge, there are only 2 white dwarf stars within reach of the average visual amateur telescope. White dwarves are intrinsically very faint, meaning that we can only see those very close to the solar system. The brightest and closest is the companion of Sirius, although this can be a challenging observation since it is often lost in the glare of Sirius itself. The only other observable one is not too far from Sirius and in good position for viewing at this time of year. It is Omicron 2 Eridani B, also known as 40 Eridani B. Here is a finder chart. Omicron 2 Eridani is colored red on the chart, which is a section of the Skalnate Pleso atlas. Orion is easily discerned to the east (left) of the star, giving easy reference. http://www.slas.us/gallery2/main.php?g2_itemId=656 Alpha, the star you can see with your unaided eye, is mag. 4.4. The white dwarf itself, Omicron 2 Eridani B, is located 83" (seconds of arc) to the east-southeast of the alpha star and is mag. 9.5- much dimmer. There is a third star, C, only 9" to the north of B, but it is a red dwarf (common as houseflies!) at mag. 11.2. In the 2009 Observer's Handbook, page 309, Roy Bishop notes: "For the observer with a small telescope, Omicron 2 Eri B is the only earth-sized object visible in the depths of interstellar space, the only visible object with a mass density far exceeding that of ordinary matter, the only accessible star no longer powered by nuclear reactions, and the only star that has expired and can still be seen." Pretty cool! Neat stuff to contemplate as you gaze at it. How about one of you imagers getting a shot of the field and posting it? Who will post a visual impression?
Hey Chuck, what about a star in the middle of a planetary? Would that be a white dwarf? Thanks, Joe --- On Sat, 1/24/09, Chuck Hards <chuck.hards@gmail.com> wrote: From: Chuck Hards <chuck.hards@gmail.com> Subject: [Utah-astronomy] White dwarfs and YOU To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Saturday, January 24, 2009, 5:29 PM Would the plural of "white dwarf" be "white dwarves"? To the best of my knowledge, there are only 2 white dwarf stars within reach of the average visual amateur telescope. White dwarves are intrinsically very faint, meaning that we can only see those very close to the solar system. The brightest and closest is the companion of Sirius, although this can be a challenging observation since it is often lost in the glare of Sirius itself. The only other observable one is not too far from Sirius and in good position for viewing at this time of year. It is Omicron 2 Eridani B, also known as 40 Eridani B. Here is a finder chart. Omicron 2 Eridani is colored red on the chart, which is a section of the Skalnate Pleso atlas. Orion is easily discerned to the east (left) of the star, giving easy reference. http://www.slas.us/gallery2/main.php?g2_itemId=656 Alpha, the star you can see with your unaided eye, is mag. 4.4. The white dwarf itself, Omicron 2 Eridani B, is located 83" (seconds of arc) to the east-southeast of the alpha star and is mag. 9.5- much dimmer. There is a third star, C, only 9" to the north of B, but it is a red dwarf (common as houseflies!) at mag. 11.2. In the 2009 Observer's Handbook, page 309, Roy Bishop notes: "For the observer with a small telescope, Omicron 2 Eri B is the only earth-sized object visible in the depths of interstellar space, the only visible object with a mass density far exceeding that of ordinary matter, the only accessible star no longer powered by nuclear reactions, and the only star that has expired and can still be seen." Pretty cool! Neat stuff to contemplate as you gaze at it. How about one of you imagers getting a shot of the field and posting it? Who will post a visual impression? _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://gallery.utahastronomy.com Visit the Wiki: http://www.utahastronomy.com
Not sure, Joe. I know that the Crab Nebula remnant is a pulsar, or spinning neutron star- which is what happens to stars more massive than white dwarves. But I suppose many planetary nebula central stars could be white dwarves- do you know of any that are easily observed visually with an amateur telescope? On Sat, Jan 24, 2009 at 5:36 PM, Joe Bauman <josephmbauman@yahoo.com> wrote:
Hey Chuck, what about a star in the middle of a planetary? Would that be a white dwarf? Thanks, Joe
Some quick research tends to indicate that by the time the white-dwarf stage has been reached, any planetary nebula blown-off by the star has long-since ceased to glow as the gas has re-combined. The planetary nebula is produced from a helium flash when the star is structurally an asymptotic giant branch star <http://en.wikipedia.org/wiki/Asymptotic_giant_branch_star>. Planetary nebula are very short-lived, on the cosmic timescale, lasting only about 10,000 years. On Sat, Jan 24, 2009 at 5:43 PM, Chuck Hards <chuck.hards@gmail.com> wrote:
Not sure, Joe. I know that the Crab Nebula remnant is a pulsar, or spinning neutron star- which is what happens to stars more massive than white dwarves. But I suppose many planetary nebula central stars could be white dwarves- do you know of any that are easily observed visually with an amateur telescope?
No, I was just curious. Thanks, Joe --- On Sat, 1/24/09, Chuck Hards <chuck.hards@gmail.com> wrote: From: Chuck Hards <chuck.hards@gmail.com> Subject: Re: [Utah-astronomy] White dwarfs and YOU To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Saturday, January 24, 2009, 5:43 PM Not sure, Joe. I know that the Crab Nebula remnant is a pulsar, or spinning neutron star- which is what happens to stars more massive than white dwarves. But I suppose many planetary nebula central stars could be white dwarves- do you know of any that are easily observed visually with an amateur telescope? On Sat, Jan 24, 2009 at 5:36 PM, Joe Bauman <josephmbauman@yahoo.com> wrote:
Hey Chuck, what about a star in the middle of a planetary? Would that be a white dwarf? Thanks, Joe
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Looking for Omicron 2 Eridani B in my planetarium software I think I found it. It is close to 37, 38 Eridani but my software calls it Keid. I have it located at 4h 15.748m -7° 37.232' Chuck, you are like reading Sue French. I want to grab my scope and run outside and look at it. jg --- On Sat, 1/24/09, Chuck Hards <chuck.hards@gmail.com> wrote: From: Chuck Hards <chuck.hards@gmail.com> Subject: [Utah-astronomy] White dwarfs and YOU To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Saturday, January 24, 2009, 5:29 PM Would the plural of "white dwarf" be "white dwarves"? To the best of my knowledge, there are only 2 white dwarf stars within reach of the average visual amateur telescope. White dwarves are intrinsically very faint, meaning that we can only see those very close to the solar system. The brightest and closest is the companion of Sirius, although this can be a challenging observation since it is often lost in the glare of Sirius itself. The only other observable one is not too far from Sirius and in good position for viewing at this time of year. It is Omicron 2 Eridani B, also known as 40 Eridani B. Here is a finder chart. Omicron 2 Eridani is colored red on the chart, which is a section of the Skalnate Pleso atlas. Orion is easily discerned to the east (left) of the star, giving easy reference. http://www.slas.us/gallery2/main.php?g2_itemId=656 Alpha, the star you can see with your unaided eye, is mag. 4.4. The white dwarf itself, Omicron 2 Eridani B, is located 83" (seconds of arc) to the east-southeast of the alpha star and is mag. 9.5- much dimmer. There is a third star, C, only 9" to the north of B, but it is a red dwarf (common as houseflies!) at mag. 11.2. In the 2009 Observer's Handbook, page 309, Roy Bishop notes: "For the observer with a small telescope, Omicron 2 Eri B is the only earth-sized object visible in the depths of interstellar space, the only visible object with a mass density far exceeding that of ordinary matter, the only accessible star no longer powered by nuclear reactions, and the only star that has expired and can still be seen." Pretty cool! Neat stuff to contemplate as you gaze at it. How about one of you imagers getting a shot of the field and posting it? Who will post a visual impression? _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://gallery.utahastronomy.com Visit the Wiki: http://www.utahastronomy.com
Be sure to let us know what you observe! Jim, 40 to about 25 years ago, I really had my head wrapped around this hobby. Today I rarely read anything to do with astronomy, and hardly ever get my scope out.. life has other things for me to do. My memory of my observing heyday isn't perfect, either. I make a lot of mistakes. I realized yesterday that I let my S&T subscription expire last November, and I have issues on my dresser from last year that I still haven't even opened. But sometimes I can recall some good stuff I've seen or read over the years. I'm just one of those hundred monkeys at a typewriter. On Sat, Jan 24, 2009 at 8:29 PM, Jim Gibson <jimgibson00@yahoo.com> wrote:
Looking for Omicron 2 Eridani B in my planetarium software I think I found it. It is close to 37, 38 Eridani but my software calls it Keid. I have it located at 4h 15.748m -7° 37.232'
Chuck, you are like reading Sue French. I want to grab my scope and run outside and look at it.
Chuck, Obviously you have forgotten more than I will ever know and you are still a walking encyclopedia. And the 2 Daves (Bernson & Bennett) are also totally amazing as walking star catalogs. So far one of the highlights of my armature experience was one night at Wolf Creek. Dave Bennett came over to my scope and took me on a 5 hours no-stop tour of the sky never once looking at any reference material and he was faster than a Goto at finding stuff. And Chuck your knowledge of lens crafting, telescope making, shoot, I can’t even begin to list the breadth of your knowledge. Even your knowledge of WWI bi-planes is incredible; almost like you were there...hehe. So, Chuck I hope you get some satisfaction passing on what you have learned, because I for one love to read and see what comes out of your mind. jg --- On Sat, 1/24/09, Chuck Hards <chuck.hards@gmail.com> wrote: From: Chuck Hards <chuck.hards@gmail.com> Subject: Re: [Utah-astronomy] White dwarfs and YOU To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Saturday, January 24, 2009, 9:30 PM Be sure to let us know what you observe! Jim, 40 to about 25 years ago, I really had my head wrapped around this hobby. Today I rarely read anything to do with astronomy, and hardly ever get my scope out.. life has other things for me to do. My memory of my observing heyday isn't perfect, either. I make a lot of mistakes. I realized yesterday that I let my S&T subscription expire last November, and I have issues on my dresser from last year that I still haven't even opened. But sometimes I can recall some good stuff I've seen or read over the years. I'm just one of those hundred monkeys at a typewriter. On Sat, Jan 24, 2009 at 8:29 PM, Jim Gibson <jimgibson00@yahoo.com> wrote:
Looking for Omicron 2 Eridani B in my planetarium software I think I found it. It is close to 37, 38 Eridani but my software calls it Keid. I have it located at 4h 15.748m -7° 37.232'
Chuck, you are like reading Sue French. I want to grab my scope and run outside and look at it.
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My post about Chuck Hards and the Daves got me to thinking how fortunate we are on this list. Another example of an incredible person is Patrick Wiggins. One night just for fun I Googled up Patrick Wiggins name and was completely amazed at the number of different locations that Patrick has been a contributor to. From what I could tell Pratrick’s comments always demonstrated a high level of understanding on several subjects and I could go on but it already sound like a speech you hear before someone gets a metal or something. One of the many things I admire, envy even, about Patrick is his ability to find and image things that are ephemeral. If I can find it I will try and post a photograph of the Columbia I took at Leeds (north of St. George) as it passed over head and was beginning to come apart. I never would have gotten that picture if it hadn’t been for Patrick’s direction. At any rate we have a lot of knowledgeable people on this list. I could go on about Daniel Turner, Joe Bauman and others but I better cut if off here. Jim Gibson
Not to mention A LOT of really wonderful human beings, like Jim Gibson... :o) --- On Sun, 1/25/09, Jim Gibson <jimgibson00@yahoo.com> wrote:
From: Jim Gibson <jimgibson00@yahoo.com> Subject: [Utah-astronomy] We are fortunate To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Sunday, January 25, 2009, 7:50 AM My post about Chuck Hards and the Daves got me to thinking how fortunate we are on this list. Another example of an incredible person is Patrick Wiggins. One night just for fun I Googled up Patrick Wiggins name and was completely amazed at the number of different locations that Patrick has been a contributor to. From what I could tell Pratrick’s comments always demonstrated a high level of understanding on several subjects and I could go on but it already sound like a speech you hear before someone gets a metal or something. One of the many things I admire, envy even, about Patrick is his ability to find and image things that are ephemeral. If I can find it I will try and post a photograph of the Columbia I took at Leeds (north of St. George) as it passed over head and was beginning to come apart. I never would have gotten that picture if it hadn’t been for Patrick’s direction. At any rate we have a lot of knowledgeable people on this list. I could go on about Daniel Turner, Joe Bauman and others but I better cut if off here. Jim Gibson
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Amen, Rich. When I read Jim's posts I can feel his excitement and enjoyment of the hobby. I live my astronomical life vicariously through him and others like him. He's doing it right. On Sun, Jan 25, 2009 at 10:28 AM, Richard Tenney <retenney@yahoo.com> wrote:
Not to mention A LOT of really wonderful human beings, like Jim Gibson... :o)
Hey Rich! Thank you so much. Rich. Maybe when the weather gets better (seems a long way off today) Maybe we can get together and we can tweak my TeleKit a bit. Jim Gibson --- On Sun, 1/25/09, Richard Tenney <retenney@yahoo.com> wrote: From: Richard Tenney <retenney@yahoo.com> Subject: Re: [Utah-astronomy] We are fortunate To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Sunday, January 25, 2009, 10:28 AM Not to mention A LOT of really wonderful human beings, like Jim Gibson... :o) --- On Sun, 1/25/09, Jim Gibson <jimgibson00@yahoo.com> wrote:
From: Jim Gibson <jimgibson00@yahoo.com> Subject: [Utah-astronomy] We are fortunate To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Sunday, January 25, 2009, 7:50 AM My post about Chuck Hards and the Daves got me to thinking how fortunate we are on this list. Another example of an incredible person is Patrick Wiggins. One night just for fun I Googled up Patrick Wiggins name and was completely amazed at the number of different locations that Patrick has been a contributor to. From what I could tell Pratrick’s comments always demonstrated a high level of understanding on several subjects and I could go on but it already sound like a speech you hear before someone gets a metal or something. One of the many things I admire, envy even, about Patrick is his ability to find and image things that are ephemeral. If I can find it I will try and post a photograph of the Columbia I took at Leeds (north of St. George) as it passed over head and was beginning to come apart. I never would have gotten that picture if it hadn’t been for Patrick’s direction. At any rate we have a lot of knowledgeable people on this list. I could go on about Daniel Turner, Joe Bauman and others but I better cut if off here. Jim Gibson
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Love to Jim. My mirror is in serious need of cleaning too, and I don't recall ever having had a peek through your TK. 20" IIRC...? --- On Sun, 1/25/09, Jim Gibson <jimgibson00@yahoo.com> wrote:
From: Jim Gibson <jimgibson00@yahoo.com> Subject: Re: [Utah-astronomy] We are fortunate To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Sunday, January 25, 2009, 3:04 PM Hey Rich! Thank you so much. Rich. Maybe when the weather gets better (seems a long way off today) Maybe we can get together and we can tweak my TeleKit a bit. Jim Gibson
--- On Sun, 1/25/09, Richard Tenney <retenney@yahoo.com> wrote:
From: Richard Tenney <retenney@yahoo.com> Subject: Re: [Utah-astronomy] We are fortunate To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Sunday, January 25, 2009, 10:28 AM
Not to mention A LOT of really wonderful human beings, like Jim Gibson... :o)
--- On Sun, 1/25/09, Jim Gibson <jimgibson00@yahoo.com> wrote:
From: Jim Gibson <jimgibson00@yahoo.com> Subject: [Utah-astronomy] We are fortunate To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Sunday, January 25, 2009, 7:50 AM My post about Chuck Hards and the Daves got me to thinking how fortunate we are on this list. Another example of an incredible person is Patrick Wiggins. One night just for fun I Googled up Patrick Wiggins name and was completely amazed at the number of different locations that Patrick has been a contributor to. From what I could tell Pratrick’s comments always demonstrated a high level of understanding on several subjects and I could go on but it already sound like a speech you hear before someone gets a metal or something. One of the many things I admire, envy even, about Patrick is his ability to find and image things that are ephemeral. If I can find it I will try and post a photograph of the Columbia I took at Leeds (north of St. George) as it passed over head and was beginning to come apart. I never would have gotten that picture if it hadn’t been for Patrick’s direction. At any rate we have a lot of knowledgeable people on this list. I could go on about Daniel Turner, Joe Bauman and others but I better cut if off here. Jim Gibson
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Rich, I have been debating going to the state liquor store and purchasing some Everclear for mirror cleaning because my mirror is as you describe yours. Also my break squeeks and my spider needs a little tweak. Jim --- On Sun, 1/25/09, Richard Tenney <retenney@yahoo.com> wrote: From: Richard Tenney <retenney@yahoo.com> Subject: Re: [Utah-astronomy] We are fortunate To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Sunday, January 25, 2009, 5:20 PM Love to Jim. My mirror is in serious need of cleaning too, and I don't recall ever having had a peek through your TK. 20" IIRC...? --- On Sun, 1/25/09, Jim Gibson <jimgibson00@yahoo.com> wrote:
From: Jim Gibson <jimgibson00@yahoo.com> Subject: Re: [Utah-astronomy] We are fortunate To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Sunday, January 25, 2009, 3:04 PM Hey Rich! Thank you so much. Rich. Maybe when the weather gets better (seems a long way off today) Maybe we can get together and we can tweak my TeleKit a bit. Jim Gibson
--- On Sun, 1/25/09, Richard Tenney <retenney@yahoo.com> wrote:
From: Richard Tenney <retenney@yahoo.com> Subject: Re: [Utah-astronomy] We are fortunate To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Sunday, January 25, 2009, 10:28 AM
Not to mention A LOT of really wonderful human beings, like Jim Gibson... :o)
--- On Sun, 1/25/09, Jim Gibson <jimgibson00@yahoo.com> wrote:
From: Jim Gibson <jimgibson00@yahoo.com> Subject: [Utah-astronomy] We are fortunate To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Sunday, January 25, 2009, 7:50 AM My post about Chuck Hards and the Daves got me to thinking how fortunate we are on this list. Another example of an incredible person is Patrick Wiggins. One night just for fun I Googled up Patrick Wiggins name and was completely amazed at the number of different locations that Patrick has been a contributor to. From what I could tell Pratrick’s comments always demonstrated a high level of understanding on several subjects and I could go on but it already sound like a speech you hear before someone gets a metal or something. One of the many things I admire, envy even, about Patrick is his ability to find and image things that are ephemeral. If I can find it I will try and post a photograph of the Columbia I took at Leeds (north of St. George) as it passed over head and was beginning to come apart. I never would have gotten that picture if it hadn’t been for Patrick’s direction. At any rate we have a lot of knowledgeable people on this list. I could go on about Daniel Turner, Joe Bauman and others but I better cut if off here. Jim Gibson
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I have no idea why Erik's post keep ending up in the content filter... =================================================== White Dwarfs, Sirius B Sunday, January 25, 2009 10:35 AM From: zaurak@digis.net To: Utah-Astronomy@mailman.xmission.com Hi All, The companion of Sirius is a white dwarf (Sirius B), as for nova remnants, the mass of the star before the cataclysm determines if it becomes a white dwarf (from what I can find in references). I wonder if M57 has a white dwarf in the center. Erik
etc... ================= White Dwarfs Continued Sunday, January 25, 2009 10:52 AM From: zaurak@digis.net To: Utah-Astronomy@mailman.xmission.com Hi All, I will answer my own question, yes the central star of M57 is a white dwarf. I have included a link from Ohio State that talks about White Dwarfs. http://www.astronomy.ohio-state.edu/~ryden/ast162_4/notes17.html Erik
Rich, thanks for making sure Erik's posts came through. Funny because I was getting them as recently as a few days ago. I think the key to what Bishop wrote (Observer's Handbook 2009 edition, pg. 309, "Expired Stars") and my recollections, is that Sirius B and Omicron 2 Eridani B are the only white-dwarves *easily seen with a small telescope. *You're not going to see the central star in M57 from your backyard with a 6-inch Newtonian, nor are you going to find the companions of cataclysmic variables with a similar set-up. These two are also very close, as such things go. Om 2 Eri B is only 16.5 light-years distant, Sirius B is what, 8.5? These objects are virtually in our own "back yard". And Om 2 Eri B has the advantage of not rubbing shoulders with the second-brightest star in Earth's sky- it's much more easily seen in the eyepiece. It's a good star-party target that is easily found. "Who wants to see a dead star, one that no longer glows from nuclear fusion?!" I sure would if I were a jr. high kid interested in science. That only leaves the definition of a "small telescope" as grist for the nit-picker's mill.
The problem comes when someone writes with a voice of authority about what "can't be done". This causes people to immediately try to prove them wrong. Bishop may regret his choice of words but it's best to remember that just because you haven't seen something, doesn't mean the other people haven't either or that next year they might be able to. I look at dozens of planetary nebula every year, and a large fraction of these have an easily seen central star. Most can be seen with a 10" which is no longer considered a particularly large telescope anymore. The standards for an "amateur" or "backyard" or "average" telescope may continue to change change with time. DT --- On Sun, 1/25/09, Chuck Hards <chuck.hards@gmail.com> wrote:
From: Chuck Hards <chuck.hards@gmail.com> Subject: Re: [Utah-astronomy] White dwarfs and YOU To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Sunday, January 25, 2009, 1:04 PM Rich, thanks for making sure Erik's posts came through. Funny because I was getting them as recently as a few days ago.
I think the key to what Bishop wrote (Observer's Handbook 2009 edition, pg. 309, "Expired Stars") and my recollections, is that Sirius B and Omicron 2 Eridani B are the only white-dwarves *easily seen with a small telescope. *You're not going to see the central star in M57 from your backyard with a 6-inch Newtonian, nor are you going to find the companions of cataclysmic variables with a similar set-up. These two are also very close, as such things go. Om 2 Eri B is only 16.5 light-years distant, Sirius B is what, 8.5? These objects are virtually in our own "back yard". And Om 2 Eri B has the advantage of not rubbing shoulders with the second-brightest star in Earth's sky- it's much more easily seen in the eyepiece. It's a good star-party target that is easily found. "Who wants to see a dead star, one that no longer glows from nuclear fusion?!" I sure would if I were a jr. high kid interested in science.
That only leaves the definition of a "small telescope" as grist for the nit-picker's mill. _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://gallery.utahastronomy.com Visit the Wiki: http://www.utahastronomy.com
The same can be said of your "central star" statement. From what I've been reading, now stellar evolutionists believe that the white dwarf stage isn't clearly reached until the planetary nebula has ceased to exist- an incredibly short lifespan of only a few tens to a hundred thousand years is typical for a planetary nebula. Central stars of visible planetaries are considered pre-white dwarf stars. The knowledge base continues to be refined as time passes. It may be that Bishop knows this but wanted to point out examples of stars unambiguously settled in the white-dwarf stage. Firmly in the stellar grave yard, with no evidence of recent nuclear reactions in the immediate environ. Bishop never made an absolute statement such as you imply; he mentioned no apertures at all. A 10" telescope isn't considered a small telescope by the general public- or with many serious amateurs. It's pretty big to me, and I've been doing this since 1968. Hair-splitting, semantic games can always be played with someone's words trying to communicate astronomy to a wide audience. Only a tiny fraction of people would jump on a soapbox and find issue with Bishop's exact choice of words. I wholeheartedly approve of Bishop's piece, and your statement does nothing to provide contrary evidence. On Sun, Jan 25, 2009 at 3:36 PM, daniel turner <outwest112@yahoo.com> wrote:
The problem comes when someone writes with a voice of authority about what "can't be done". This causes people to immediately try to prove them wrong. Bishop may regret his choice of words but it's best to remember that just because you haven't seen something, doesn't mean the other people haven't either or that next year they might be able to.
I look at dozens of planetary nebula every year, and a large fraction of these have an easily seen central star. Most can be seen with a 10" which is no longer considered a particularly large telescope anymore. The standards for an "amateur" or "backyard" or "average" telescope may continue to change change with time.
participants (5)
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Chuck Hards -
daniel turner -
Jim Gibson -
Joe Bauman -
Richard Tenney