Task:
Based on the paper I have written previously (which only has introduction section now, provided below), in a new paragraph in my introduction section (provided below), write down the object/subject I choose and the related scientific questions. Then following these info I provided, write a paragraph or two (3- 5 sentences per paragraph; more is okay) to address the scientific questions listed below on your chosen object/subject. You must cite the paper(s) you find, as they are supposed to help you address these questions!
Please note that:
Do not plagiarize! This includes (but not limited to): Do not copy word by word from any reading materials. Do not simply “translate” a paragraph from the reading material into your own words sentence by sentence. The words, phrases and expressions should not be too fancy, please keep them simple and accessible. Please make sure be faithful to the facts.
Object/Subject: Supernova – photometry of a type Ia supernova to measure its distance
Scientific Question: What is the physical nature of my chosen object (that is, type Ia supernovae)? Why do we want to study them scientifically? For example, how would they reveal new stellar astrophysics (just an example!)?
References I’ve searched: (You can ONLY refer to the following papers in this task. DO NOT write and express your words and results without foundation!! Please read the following papers carefully and be faithful about the facts and results. Please double-check your writing based on them if needed. )
- [Observational Clues to the Progenitors of Type Ia Supernovae] Type Ia supernovas progenitors, just focusing on the first part — Introduction — of this paper. I do not care the progenitor system of SNe Ia: https://arxiv.org/pdf/1312.0628
- [THE HUBBLE CONSTANT] paper about measurement of the Hubble constant, please focusing on 3.6 Type Ia supernovae. https://arxiv.org/pdf/1004.1856
- [Over-Luminous Type Ia Supernovae and Standard Candle Cosmology] reading the introduction part for this paper, only focusing on the physical nature of type Ia supernovae, what’s the role of type Ia SNe in measuring distance, and why we use them to measure distance, and why measuring distance matters: https://arxiv.org/pdf/2503.13904
- [Observations of type Ia supernova SN 2020nlb up to 600 days after explosion, and the distance to M85] mainly focusing on how they use photometry of type Ia supernovae to measure the distance, what’s the nature of type Ia SNe, what’s the point in using them to measure the distance (scientific significance) https://arxiv.org/pdf/2401.08759
- [Hydrodynamic Predictions for the Next Outburst of T Coronae Borealis It will be the Brightest Classical or Recurrent Nova Ever Observed in X-rays] Latest paper on T Cr B, which is a theory paper, but the introduction section has a nice description of the recent development on transient and type Ia supernovae: https://arxiv.org/pdf/2502.10925
- [Type Ia supernova SN 2003du optical observations] paper about optical observations for type Ia SNe 2003du. also focusing on how they use photometry of type Ia supernovae to measure the distance, what’s the nature of type Ia SNe, what’s the point in using them to measure the distance (scientific significance) https://arxiv.org/pdf/astro-ph/0409494
- [SN 2013aa and SN 2017cbv Two Sibling Type Ia Supernovae in the spiral galaxy NGC 5643] paper about two type Ia SNe (SN 2013aa and SN 2017 cbv). also focusing on the physical nature of type Ia supernovae, what’s the role of type Ia SNe in measuring distance, and why we use them to measure distance, and why measuring distance matters: https://arxiv.org/pdf/2004.13069
- [A Common Explosion Mechanism for Type Ia Supernovae] may be in this paper there are some facts about the nature of type Ia SNe: https://arxiv.org/pdf/astro-ph/0702351
- [A Precise Distance Indicator Type Ia Supernova Multicolor Light Curve Shapes] maybe some insights on how and why we use Type Ia SNe as distance indicator: https://arxiv.org/pdf/astro-ph/9604143
- [Type Ia Supernova Explosion Models] paper about Type Ia SNe explosion models: https://arxiv.org/pdf/astro-ph/0006305, there may be some physical nature of type Ia SNe and the reasons why we need to study them.
My paper to be added (keep the finished introduction and add new paragraph in the end):
\begin{document}
\title{ObsAstro25 Project2}
\section{Introduction}
%%%P2R2%%%
Supernovae (SNe) are relatively rare explosive events in a certain galaxy, which mark the end of a star's life or the runaway nuclear fusion of a specific type of star called a white dwarf \citep{Gal-Yam2017}. They are often studied by extragalactic SNe -- by looking at other galaxies across the Universe. Discovering these unpredictable events typically works in two ways: observers either repeatedly take images of many individual galaxies, looking for a new point of light source that was not there before, or they survey large patches of the sky to catch any field SNe \citep{Yamaoka2016}.
Once a potential SNe candidate is detected, the primary method used to study its nature and classify it is spectroscopy. Analyzing the spectrum of an SNe provides invaluable information on its composition and dynamics \citep{Yamaoka2016}. To be more specific, the presence or absence of certain spectral lines, such as those from hydrogen or helium, observed near the peak brightness of SNe, forms the basis of the classification system. For example, Minkowski initially categorized SNe based on the presence (Type II) or absence (Type I) of the Balmer lines, indicating the hydrogen features in their spectra \citep{Gal-Yam2017}. These spectral features allow astronomers not only to determine the supernova's type (and subtypes like Ia, Ib, Ic, etc.) but also to estimate its age since the explosion, providing insights into the underlying physical processes\citep{Gal-Yam2017}.
%%%P2R1%%%
Type Ia supernovae (SNe Ia), resulting from the thermonuclear runaway of a white dwarf (WD) in a binary system, represent a crucial class of transient phenomena in astrophysics \citep{Filippenko1997}.
These events, which do not exhibit hydrogen lines in their spectra \citep{Branch1993}, are primarily understood to arise either from the merger of two WDs or through the accretion of material onto a WD from a companion star, eventually leading it to exceed the Chandrasekhar mass limit ($\sim$1.4$M_\odot$) \citep{HoyleFowler1960, Nomoto1984}.
Notably, SNe Ia serve as invaluable "standardizable candles" for extragalactic distance measurements, playing a pivotal role in the discovery of the accelerating expansion of the Universe and the subsequent investigation of dark energy \citep{Riess1998, Perlmutter1999}.
The spectroscopic and photometric study of these transients provides critical insights into their explosion mechanisms, progenitor systems, and their utility in cosmology.
We examined the SNe detected by the Zwicky Transient Facility \citep{ZTF2019} and selected the bright candidates that were observable at Xinglong on the night
of May 10, 2025.
\bibliography{refs}{}
\bibliographystyle{aasjournalv7}
\end{document}