Speeding-Bullet Star Mira Leaves Enormous Streak Across Sky

[Smersh]

RobNissen<br /><font color="yellow">I believe Mira is one of only three stars (Mira, Betalgeuse, Sun) that has had its disk resolved.</font><br /><br />Well I've learned something there. I didn't know there were ANY stars other than the Sun that have had their disc resolved! I was always under the impression they were so distant they just remained a point of light.<br /><br />3488<br /><font color="yellow">AFAIK, Antares & Arcturus have a while back & more recently Altair, Regulus & Vega. </font><br /><br />Thanks Andrew. Does anyone know which telescopes were used for this disc resolving? Was it the HST or something else?<br /> <div class="Discussion_UserSignature"> <h1 style="margin:0pt;font-size:12px">----------------------------------------------------- </h1><p><font color="#800000"><em>Lady Nancy Astor: "Winston, if you were my husband, I'd poison your tea."<br />Churchill: "Nancy, if you were my wife, I'd drink it."</em></font></p><p><font color="#0000ff"><strong>Website / forums </strong></font></p> </div>

 

[MeteorWayne]

AFAIK, the HST does not have sufficient angular resolution.<br /><br />I recall they are earth based, dozens of meters in diameter. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[robnissen]

Betalgeuse and Mira were both imaged by Hubble, as far as the others (which I did not know about until yesterday -- thx Andrew), I don't know.<br /><br />Back to my original question, does anyone have any theories as to why the Hubble image I posted above, which was taken IN UV!, did not show the tail?

 

[MeteorWayne]

My guess would be sensitivity.<br />On the image you posted, the star is way overexposed, so it wouldn't have had a chance to show a fainter tail.<br /><br />The recent study was optimised to examine faint details, AFAIK.<br /><br />Once it's overexposed (as the first image was) the bit buckets are full and can show no more detail, so that's generally when the exposure is stopped.<br /><br />We'll have to check, did they occult Mira to allow registration of the fainter detail?<br />I admit I don't know . <br /><br />MW <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[nec208]

Dam I did not know we have 2 threads of the same topic on the go!!<br /><br />I don't think it was overexposed because there is a press release on it. <br /><br />In basic school books stars do not have tails or move at very fast speed .<br /><br />This tells me it world be more of a big comet or some big star hit by some other big star and it is spinning out of control.<br /><br />Has for why it is at supersonic speeds that sounds fake .I know of nothong in space that moves at supersonic speeds .<br /><br /><br /> <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

That's why I suggested you look at a forum first to see if there's already a post on a subject before you do.<br />It's good etiquette.<br /><br />Basic books wouldn't have considered this since it a new discovery.<br />The first one.<br />Breaking science news (science does that a lot)<br /><br />It need not have been hit by anything to be moving at that speed; there are several other possible explanations, all more likely.<br />One of which, maybe it's in a fast orbit around the Milky Way.<br /><br />Maybe it is from a galaxy that was absorbed by the MW.<br /><br />Maybe it's a halo star.<br /><br />Maybe it formed in a multiple star system and was ejected.<br /><br />Let's let some followup observations take place, and give it some time to be thought about.<br /><br />Discoveries happen fast.<br />Understanding takes longer <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[robnissen]

<font color="yellow">Has for why it is at supersonic speeds that sounds fake .I know of nothong in space that moves at supersonic speeds . </font><br /><br />You should probably go back and review your school books. Virtually EVERYTHING in space "moves at supersonic speeds." Supersonic, merely means faster than the speed of sound, which at standard temperature and pressure is aboout .3 Km/sec. There is very little in space that doesn't move at .3 km/sec relative to its host star in the case of solar system objects and relative to its host galaxy for stars. This star is moving about 135 km/sec, which is fairly fast for a star, but not outside the range of speeds that are seen for stars. BTW, even man-made objects move well beyond super-sonic speeds in space. New Horizons is currently moving about 22Km/sec or about 1/6 the speed of this star.<br /><br />

 

[Smersh]

Well I suppose the Galaxy Evolution Explorer will now be on the lookout for other stars that have streaming tails would it? <br /><br />Since Mira is a red giant, could that be of any significance does anyone think, re the tail? It does shed a large amount of surface material, as said in the NASA report, which presumably forms the tail. <div class="Discussion_UserSignature"> <h1 style="margin:0pt;font-size:12px">----------------------------------------------------- </h1><p><font color="#800000"><em>Lady Nancy Astor: "Winston, if you were my husband, I'd poison your tea."<br />Churchill: "Nancy, if you were my wife, I'd drink it."</em></font></p><p><font color="#0000ff"><strong>Website / forums </strong></font></p> </div>

 

[MeteorWayne]

That seems like a likely explanation for the tail.<br />Stars that are shedding mass at that rate have enough mass out there to make a detectable tail.<br /><br />I mean the sun has a stream of particles downstream from the heliopause, but it's probably too thin to detect at this time.<br /><br />Give us a few billion years <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[3488]

This is a most fascinating development.<br /><br />I suspect Mira is either a halo star or is from a merged dwarf galaxy. Mira is moving at a tremendous<br />speed in relation to most others in the local 'hood'. <br /><br />Yes there is mass loss on a large scale with Mira. Shedding ONE Earth mass every TEN YEARS, or one Jupiter mass every, 3,180 Years, or<br />one Moon mass every 45 Days!!!!!<br /><br />I think with our sun, you are correct MeteorWayne. Although the Sun is shedding a <br />little mass, it is far too low a rate, to be detectable.<br /><br />Perhaps GALEX should look at Betelgeuse, Antares, etc too.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[robnissen]

<font color="yellow">This is a most fascinating development.</font><br /><br />Agreed. <br /><br />Stars with tails are probably limited to Red Giants because the escape velocity at the surface will be MUCH lower than for main sequence stars.<br /><br />I do have one question, however. Mira is traveling at about 135km/sec. Any mass it ejects will also be traveling at about 135km/sec. There does not appear to be anything that would slow the mass down after it is ejected, so why isn't there a very short tail, rather than 13 LY long? My WAG would be that the mass interacts with previous mass ejected creating friction that would both heat and slow the particles down such that they would eventually drag out as a very long tail. I have no idea, however, if that is a feasible answer.

 

[3488]

Or that the instersteller medium is slightly denser in Mira's current location??<br /><br />Dunno really.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[nec208]

Stars with tails are probably limited to Red Giants because the escape velocity at the surface will be MUCH lower than for main sequence stars. <br /><br />--------------------------------------------------------------<br /><br />Does this pose a danger to earth?<br /><br /> <div class="Discussion_UserSignature"> </div>

 

[nec208]

I would say any Stars with tails moving very fast or Red Giants do not sound good.<br /> <div class="Discussion_UserSignature"> </div>

 

[robnissen]

It depends. The gravitational effect of a red giant passing near the sun would be no different than any other star (the mass of red giant stars is no more than a few masses more than the sun, massive stars do not become red giants.) But because of its massive size, a collesion would be more likely. I have no idea what the gravitatinal effects on Earth would be if a star passed by around the orbit of Jupiter, but if it was a red giant, it would swallow us. As far as the tail, its hard to say what its make up is, but considering its spread over 3 times farther than AC, it probably is not very dense and wouldn't cause major problems.