Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Nova V1112

  • Please log in to reply
7 replies to this topic

#1 msvtrove

msvtrove

    Lift Off

  • -----
  • topic starter
  • Posts: 21
  • Joined: 04 Oct 2020
  • Loc: 28.51°N, 77.01°E

Posted 11 January 2021 - 01:43 PM

So happened to watch Nova V1112 Per on December 16, 2020, it was then slightly brighter then HD276383 which is of magnitude 9.6. Today when I tried to see it again, it was gone. Sad to see it go. They say nova happens in a binary system, one of which is white dwarf and other is  main sequence star of class G or below that. So isn’t watching nova is a indirect way to see a binary star system? It confuses me a bit that since fainter one is a white dwarf and not visible unless it steals hydrogen and go boom, but what about its companion star? Why not companion star is always visible? And if companion star is always visible then which star is companion of Nova V1112?



#2 Astrojensen

Astrojensen

    Voyager 1

  • *****
  • Posts: 13,915
  • Joined: 05 Oct 2008
  • Loc: Bornholm, Denmark

Posted 11 January 2021 - 02:09 PM

The thing about novae is that when they go kablammo, they REALLY go kablammo and increase their brightness by 10 - 12 magnitudes or more. This means that the combined light of the progenitor star and its companion is often WAY too faint to be detected visually and finding it even photographically can be something like finding a needle in a haystack, unless you follow it continuously all the way down as it fades. The progenitor to V1112 Per was fainter than mag 20. 

 

 

Clear skies!

Thomas, Denmark


  • ShaulaB, flt158 and msvtrove like this

#3 Rich (RLTYS)

Rich (RLTYS)

    Fly Me to the Moon

  • *****
  • Posts: 7,248
  • Joined: 18 Dec 2004
  • Loc: Glen Burnie (Maryland)

Posted 11 January 2021 - 04:52 PM

Wish I could've observed this Nova more but the weather has been garbage. frown.gif  Here's a lightcurve of V1112 Per as of today.

 

 

Attached Thumbnails

  • V1112 Lightcurve 1-11-21.png

  • flt158 and msvtrove like this

#4 Organic Astrochemist

Organic Astrochemist

    Apollo

  • *****
  • Posts: 1,074
  • Joined: 10 Jan 2015

Posted 11 January 2021 - 06:02 PM

So happened to watch Nova V1112 Per on December 16, 2020, it was then slightly brighter then HD276383 which is of magnitude 9.6. Today when I tried to see it again, it was gone. Sad to see it go. They say nova happens in a binary system, one of which is white dwarf and other is main sequence star of class G or below that. So isn’t watching nova is a indirect way to see a binary star system? It confuses me a bit that since fainter one is a white dwarf and not visible unless it steals hydrogen and go boom, but what about its companion star? Why not companion star is always visible? And if companion star is always visible then which star is companion of Nova V1112?


The luminosity of a star depends on both the temperature and the size. White dwarfs are hotter than giant stars, but they are very small and therefore not very luminous.

Energy and matter that was stored in the white dwarf gets suddenly released with a runaway nuclear chain reaction. This creates a huge envelope that is much bigger than the pair and is dense enough that we only see the outer layer. The outer layer Is like the surface of a star with a gargantuan radius and therefore a stupendous luminosity.
  • flt158 and msvtrove like this

#5 msvtrove

msvtrove

    Lift Off

  • -----
  • topic starter
  • Posts: 21
  • Joined: 04 Oct 2020
  • Loc: 28.51°N, 77.01°E

Posted 11 January 2021 - 09:34 PM

Wow, I feel at peace now. 

That graph by Rich explains why I cannot see it anymore. V1112Per, crossed visibility capability of my scope near 27th December 2020.

 

1. Anyways why do Novae faint? Is it like materials expelled by white dwarf become less dense?

 

2. What does rate of decrease tells us? Is it the rate at which gas is expanding?

 

3. How far is V1112Per ? 
 

Thanks.



#6 descott12

descott12

    Gemini

  • *****
  • Posts: 3,109
  • Joined: 28 Sep 2018
  • Loc: Charlotte, NC

Posted 11 January 2021 - 09:51 PM

There is alot of good info in this thread

https://www.cloudyni...eus-n-per-2020/



#7 Organic Astrochemist

Organic Astrochemist

    Apollo

  • *****
  • Posts: 1,074
  • Joined: 10 Jan 2015

Posted 11 January 2021 - 11:54 PM

Wow, I feel at peace now.

That graph by Rich explains why I cannot see it anymore. V1112Per, crossed visibility capability of my scope near 27th December 2020.

1. Anyways why do Novae faint? Is it like materials expelled by white dwarf become less dense?

2. What does rate of decrease tells us? Is it the rate at which gas is expanding?

3. How far is V1112Per ?

Thanks.

1. The outer material that was ejected becomes less dense, cooler and more transparent. But inner material falls back towards the white dwarf and becomes denser and hotter, but it also becomes more transparent because intense radiation blows away the electrons that would absorb light.

The size of the opaque region decreases and the luminosity decreases.

2. This is very complicated.

3. I don’t know.

Edited by Organic Astrochemist, 11 January 2021 - 11:57 PM.


#8 robin_astro

robin_astro

    Apollo

  • -----
  • Posts: 1,224
  • Joined: 18 Dec 2005

Posted 12 January 2021 - 09:44 AM

 

 

3. How far is V1112Per ? 
 

 

See the main thread on this nova here for a rough back of envelope estimate. 

 

https://www.cloudyni...020/?p=10757146

 

The sun (a main sequence G star) at this distance and including the interstellar extinction would have an apparent magnitude of ~ 21 

 

Cheers

Robin




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics