Hubble Space Telescope
Cycle 11 General Observer Proposal
Dust in the Wind: Spectroscopic Analysis of Dust
Formation in conjunction with light curves of the D
class Novae
Principal Investigator: Mr. Davin Fernandez
Institution: Stony Brook University
USA/NY
Electronic mail: davin.p.fernandez@gmail.com
Scientific category: HOT STARS
Scientific keywords: NOVA SHELLS, SPECTROSCOPY, MULTIWAVELENGTH
Instruments: STIS, WFPC3 Proprietary period: 12
Cycle 11 primary orbits: 100
Cycle 11 parallel orbits: 0
Special Proposal Types: Innovative
Abstract
Richard Strope outlines seven different classes for novae defined by their light curves,
established in his Catalog of 93 Nova Light Curves: Classification and Properties. Strope
defines one of these classes as the D class or Dust dip nova. This class is categorized by the
decay of the light curve in the optical being interrupted by a sudden fast decline, a minimum,
and then a recovery close to the original decay of the light curve. This is thought to be due
to a dust cloud forming around the nova as it decays, absorbing optical light and then re
emitting in the infrared as an excess. Studying the dust of these novae via spectroscopy has
not been attempted previously. By examining the spectroscopy of the dust, we can form
a better image of how the dust is interacting with the light being emitted by the D class
novae.
Mr. Davin Fernandez
Dust in the Wind: Spectroscopic Analysis of Dust Formation in conjunction with light
curves of the D class Novae
Investigator
Mr. Davin Fernandez
PI:
CoI:
Total number of investigators:
Observing Summary:
Target
RA
M31N
00 42 42.66
2011-01A
Institution
Stony Brook University
Country
USA/NY
2
DEC
41 19 14.2
V
18.1
Configuration,mode,aperture
spectral elements
STIS/WFC3 SPECTROSCOPY/IMAGING
Unknown
STIS/WFC3 SPECTROSCOPY/IMAGING
Total
orbits
10
Flags
DUP
10
DUP
M31N
2010-12A
00 40 24.39
41 04 03.9
16.7
M31N
2010-10A
00 42 45.82
41 24 22.0
17.9
STIS/WFC3 SPECTROSCOPY/IMAGING
10
DUP
M31N
2010-09A
00 42 23.32
42 17 08.6
17.2
STIS/WFC3 SPECTROSCOPY/IMAGING
10
DUP
M31N
2010-08A
00 43 28.28
41 41 25.0
18.5
STIS/WFC3 SPECTROSCOPY/IMAGING
10
DUP
M31N
2010-07A
00 43 20.11
41 21 23.7
20.6
STIS/WFC3 SPECTROSCOPY/IMAGING
10
DUP
M31N
2010-06A
00 43 07.52
41 19 48.7
18.1
STIS/WFC3 SPECTROSCOPY/IMAGING
10
DUP
M31N
2010-05A
00 42 35.90
41 16 37.5
17.6
STIS/WFC3 SPECTROSCOPY/IMAGING
10
DUP
M31N
2010-04A
00 42 44.76
41 15 12.0
16.5
STIS/WFC3 SPECTROSCOPY/IMAGING
10
DUP
M31N
2009-12A
00 40 19.41
41 15 47.6
16.6
STIS/WFC3 SPECTROSCOPY/IMAGING
10
DUP
Grand total orbit request
100
2
Mr. Davin Fernandez
Dust in the Wind: Spectroscopic Analysis of Dust Formation in conjunction with light
curves of the D class Novae
Scientific Justification
Developing a complete picture of the processes surrounding a nova is integral to properly
understanding the differences between each event. By examining the spectroscopy of the dust
we can develop a better understanding of it’s composition while it forms around the D (Dust
Dip) class of novae. From this, a correlation between the spectroscopy of the dust and the
light curves of these novae can be developed. This connection between the attributes of the
dust being formed and the resulting light curves of the D class novae will help in creating
a more thoroughly detailed explanation of this classification. By using the spectroscopic
analysis of the dust, a blackbody spectrum can be calculated for how the dust should be
reradiating that absorbed light. This excess of light being re emitted in the infrared can
then be estimated and compared to the observed differences in re emitted excess of the D
class novae.
Should none of the observed novae be D class, a spectroscopic image will still be compiled
of each nova. Although the majority of novae seem to fall into the S (or smooth) class of
novae, developing a spectroscopic understanding of these common S class novae will still
prove helpful in constructing the baseline image of novae and thus the subtle differences
between the other classes as they deviate.
The current understanding of novae and how they differ from one another is based
purely on the characteristics of the light curve of each novae. Through an examination of
the physical phenomena thought to be occuring around these novae, a more concrete example
can be developed upon which our classification system can be based. This development of
a model nova will lead to an improved basis from which other models of nova classes can be
built.
Description of the Observations
I will be observing 10 different novae in the M31 (Andromeda) Galaxy. Each nova will be
observed for 10 orbits, requiring a total of 100 orbits for observations. Each nova will be
observed in the optical wavelength as well as a spectroscopic image of the nova. Each nova
should have an exposure time of 5 to 10 seconds for each wavelength (I,B,V, and K) as well
as 10 seconds for their spectroscopy. This will require a total exposure-time of 3000 to 5000
seconds for all observations.
Special Requirements
The light curves of novae are time-sensitive due to the decay rate of the novae. Because of
this, the novae should be observed as close to the initial time of the nuclear fusion flash as
possible.
Coordinated Observations
These observations will not be affiliated with any other facilities.
3
Mr. Davin Fernandez
Dust in the Wind: Spectroscopic Analysis of Dust Formation in conjunction with light
curves of the D class Novae
Justify Duplications
Measuring the light curves of these novae will help to reaffirm the decay rates and attributes
of the novae when the spectroscopic images are compared to their corresponding light curves.
Previous HST Programs
None.
4