Difference between revisions of "Triggers:CNe"

From Gaia Science Alerts Working Group
Jump to navigationJump to search
(Created page with '* there is roughly 30 novae per year in the Milky Way and about 20 in other galaxies * absolute magnitude <math>M_V = -8 mag</math> * amplitude between 6 and 15 mag * quick rise ...')
 
 
(7 intermediate revisions by the same user not shown)
Line 1: Line 1:
* there is roughly 30 novae per year in the Milky Way and about 20 in other galaxies
+
Close binary systems with orbital periods from 0.05 to 230 days. One of the components of these systems is a hot dwarf star that suddenly, during a time interval from one to several dozen or several hundred days, increases its brightness by 7-19 mag in V, then returns gradually to its former brightness over several months, years, or decades. Cool components may be giants, subgiants, or dwarfs of K-M type
 +
(from GCVS).
 +
 
 +
* there is observed roughly 10 classical novae per year in the Milky Way and about 40 in other galaxies
 
* absolute magnitude <math>M_V = -8 mag</math>
 
* absolute magnitude <math>M_V = -8 mag</math>
* amplitude between 6 and 15 mag
+
* spectra near maximum light resemble A-F absorption spectra of luminous stars at first
 +
* spectra at minimum light resemble spectra of Wolf-Rayet stars.
 +
* amplitude between 7 and 19 mag in V
 
* quick rise of few days
 
* quick rise of few days
 
* slow decline, between few days and 100 days (fast: type A, slow: type B, very slow: type C)
 
* slow decline, between few days and 100 days (fast: type A, slow: type B, very slow: type C)
 
* 15 days after maximum its Mv = -5.5mag, independent on speed or class
 
* 15 days after maximum its Mv = -5.5mag, independent on speed or class
 +
* small changes at minimum light may be present
 +
 +
Exemplary observations of a very fast nova with 0.3m Meade telescope: [[http://uk.arxiv.org/abs/1003.5371 Munari and Dallaporta]].
 +
 +
'''Recurrent novae''':
 +
* are produced by a white dwarf star and a red giant circling about each other in a close orbit
 +
* recurrent every 10-100 years
 +
* smaller amplitude: 4-9 mag
 +
* M_V at minimum is about 0-1 mag
 +
* example: RS Oph - 3 outbursts between 1957 and 1991 (AAVSO), exhibits some small variation in the baseline in minimum
 +
* decline within few days
 +
 +
----
 +
Short transient searches in the other galaxies revealed possible new sub-class of novae: [http://uk.arxiv.org/abs/1003.1720 Kasliwal et al. 2010]. They usually stay above the Gaia detection limit for not more than 10 days.
 +
 +
----
 +
Interesting paper on classification and properties of novae: [[http://uk.arxiv.org/abs/1004.3698 Strope, Schaefer & Henden 2010]]

Latest revision as of 15:59, 16 July 2013

Close binary systems with orbital periods from 0.05 to 230 days. One of the components of these systems is a hot dwarf star that suddenly, during a time interval from one to several dozen or several hundred days, increases its brightness by 7-19 mag in V, then returns gradually to its former brightness over several months, years, or decades. Cool components may be giants, subgiants, or dwarfs of K-M type (from GCVS).

  • there is observed roughly 10 classical novae per year in the Milky Way and about 40 in other galaxies
  • absolute magnitude <math>M_V = -8 mag</math>
  • spectra near maximum light resemble A-F absorption spectra of luminous stars at first
  • spectra at minimum light resemble spectra of Wolf-Rayet stars.
  • amplitude between 7 and 19 mag in V
  • quick rise of few days
  • slow decline, between few days and 100 days (fast: type A, slow: type B, very slow: type C)
  • 15 days after maximum its Mv = -5.5mag, independent on speed or class
  • small changes at minimum light may be present

Exemplary observations of a very fast nova with 0.3m Meade telescope: [Munari and Dallaporta].

Recurrent novae:

  • are produced by a white dwarf star and a red giant circling about each other in a close orbit
  • recurrent every 10-100 years
  • smaller amplitude: 4-9 mag
  • M_V at minimum is about 0-1 mag
  • example: RS Oph - 3 outbursts between 1957 and 1991 (AAVSO), exhibits some small variation in the baseline in minimum
  • decline within few days

Short transient searches in the other galaxies revealed possible new sub-class of novae: Kasliwal et al. 2010. They usually stay above the Gaia detection limit for not more than 10 days.


Interesting paper on classification and properties of novae: [Strope, Schaefer & Henden 2010]