STAR VANISHES IN ORION IF COMPARED IN TWO PHOTOS

[Pankaj 124]

Hi All. 

I took a photograph of the Orion Nebula using my Orion ST 80A Achromatic Refractor on 15th Nov 2015. Though the photo seemed a bit out of focus, but the result encouraged me to again go in for a session from the same location again on 9th Dec 2015 using the same equipment. Camera was unmodded Canon 1200D fitted at prime focus with the scope that was mounted on a NEQ6 on both occasions.

Today I was comparing the two photos and judging the location of each star. Doing so, I across a star that was present on the photo on 15th Nov 2015, but was not present in the photo taken on 9th Dec 2015.

Can someone explain the possible reasons for this. Attached are the two photos for reference.

[BeanerSA 134]

If it isn't down to changed conditions, then it might be a minor planet or similar object.

[andyboy1970 396]

Just looked through my Orion images and it is there in some but mostly it is missing.

[JB80 2,779]

Using stellarium to go back and look at those nights I'm seeing that Orion is right in the path of any number of satellites streaming through, it could be one of them or a geo synchronous satellite even, I think there are a few in that area.

Just a guess, I can't say for sure.

Edited December 12, 2015 by JB80

[Pig 6,107]

LoL @ Vanishes   a little dramatic would you say.

Well spotted though.... do you really judge the location of each star in your images ? If so that's what I call true commitment

[xtreemchaos 14,567]

id say its down to changing  conditions, heres a image i took on the 3rd and theres only 2 stars. charl.................after comment, asteroid sounds good.

Edited December 12, 2015 by xtreemchaos

[Knight of Clear Skies 5,389]

Well spotted. Here's a deeper view of the same region from last year. It took me a while to match up the stars but I can't see anything there, so I think it's unlikely to be a variable star.

As others say an asteroid or geosynchronous satellite are real possibilities. If anyone else has any images around these dates to share it might be possible to get a better idea by seeing if it moves or varies in brightness, would be fun to see if we can pin this down. It appears very close in brightness to the two adjacent stars so checking them should give a decent magnitude estimate.

I'd be surprised if it's a nova, and I think a supernova can be ruled out due to the amount of dust in the area.

Edited December 12, 2015 by Knight of Clear Skies

[Stu 30,309]

Got it! It was an asteroid!! Specifically 747 Winchester which was in exactly that position on 15th November but not on 15th December!

Nice one!! [emoji106][emoji106]

[Knight of Clear Skies 5,389]

Nice find Stu, what software did you use please?

Looking at the wiki page it's a biggie, estimated to be 170km across.

[Stu 30,309]

SkySafari Pro. The hardest bit was identifying the star field in question, once I'd done that I just stepped through to the date and the asteroid appeared. Mag 10.5 apparently.

[Knight of Clear Skies 5,389]

Here's where it is now if anyone is interested, still in Orion and taking a path parallel to the arm/bow over the next couple months.

Edited December 12, 2015 by Knight of Clear Skies

[Pankaj 124]

I have no knowledge of this asteroid. But great work indeed Stu. please make doubly sure that its the asteriod only. Can your software also show when this asteroid will be next in this position ?

[Mr Spock 7,207]

Nice capture and an interesting object.

[Stu 30,309]

I have no knowledge of this asteroid. But great work indeed Stu. please make doubly sure that its the asteriod only. Can your software also show when this asteroid will be next in this position ?

The next time it is in the Orion area seems to be in 2021!

[happy-kat 5,798]

My skysafari plus version is not listing that comet.

Good spot :-)

[Pankaj 124]

@ Stu - 2021 !! Man that is pretty long time. 

This means that in any photograph taken 2-5 years before 15th Nov 2015, should not have this spec of light in this particular location. 

I would suggest everyone to please look for this in photographs taken between Nov 2011 to Nov 2015. Do you think I am right on the calculation Stu ?

Thanks

Pankaj

[Stu 30,309]

Well it looks like it was close to Betelgeuse on 21st August 2010, worth looking for on past images.

[BeanerSA 134]

I think someone's tin foil hat is getting a bit tight.

[CountBorgula 26]

Nice work, keep looking, you never know you might discover a new object like this!  I have a question, I am looking to get a DSLR for christmas.  We want to take this on a holiday to Sri Lanka, but also to double up as an AP camera.  How would you rate the 1200D for that purpose?

[jtlandreneau 460]

I had been following this thread with a lot of interest - http://www.cloudynights.com/topic/518805-curious-object-in-m42/ - I think you caught the same object (the date seems right), which was identified as 747 Winchester

good catch!

[Pankaj 124]

Nice work, keep looking, you never know you might discover a new object like this!  I have a question, I am looking to get a DSLR for christmas.  We want to take this on a holiday to Sri Lanka, but also to double up as an AP camera.  How would you rate the 1200D for that purpose?

I find 1200D to be very comfortable. Its an 18MP camera. You can also look at the next version which has a 24mp sensor. For me, 1200D is sufficient for next 2-3 years.

[Stub Mandrel 12,873]

Darn! I took a shot of teh bottom half of Orion on 9 December - and it would be just outside the frame :-(

Nice catch.

[ollypenrice 28,385]

I find 1200D to be very comfortable. Its an 18MP camera. You can also look at the next version which has a 24mp sensor. For me, 1200D is sufficient for next 2-3 years.

This sounds like far too many pixels to me (for anythng but a very short FL). Having undersized pixels is a disadvantage once they give a resolution which falls below what the seeing and guiding will allow - and this soon happens. High pixel counts may be good in the daytime but in AP they should be matched sensibly to the focal length.

Fascinating find by the OP and Stu. Great stuff.

Olly

[lensman57 1,741]

I find 1200D to be very comfortable. Its an 18MP camera. You can also look at the next version which has a 24mp sensor. For me, 1200D is sufficient for next 2-3 years.

Do you realize that you are talking Astro Photography here not daytime snapping. My Atik 314L+ has a sensor of 1.4 MP, and it is still going strong. What on earth makes you think that you need 24 MP for any reason? Before you answer this let me tell you that I was and still am a Technical Photographer for the last 30 years so I do know a thing or two about photography. Use what ever is at your disposal but forget the MP measure of a camera as a yard stick for quality, that one comes from you. For your information the size of the sensor on the deep space camera  of the Hubble Scope Telescope is 800 X 800 pixels square. Now that is food for thought isn't it?

Kind Regards,

A.G

Edited December 18, 2015 by lensman57

[Pankaj 124]

Do you realize that you are talking Astro Photography here not daytime snapping. My Atik 314L+ has a sensor of 1.4 MP, and it is still going strong. What on earth makes you think that you need 24 MP for any reason? Before you answer this let me tell you that I was and still am a Technical Photographer for the last 30 years so I do know a thing or two about photography. Use what ever is at your disposal but forget the MP measure of a camera as a yard stick for quality, that one comes from you. For your information the size of the sensor on the deep space camera  of the Hubble Scope Telescope is 800 X 800 pixels square. Now that is food for thought isn't it?

Kind Regards,

A.G

Hi AG

I am just learning AP after 18 years of visual observation. Started AP with the existing camera that I had and found that its quite ok for photographing most of the celestial objects. Earlier I use to sketch while visually observing. AP with the currnt camera has been rewarding in terms of saving time and having more accurate information on hand. I will certainly graduate to more sophisticated cameras in future. By the way, is there a thimb rule, or set calculative method for selecting a MP for the next camera that I should buy ?