#!/usr/bin/env python
# coding: utf-8

# # Quickstart

# If you have a working version of Python installed on your system, it is easy to install Lightkurve and its dependencies using the ``pip`` package manager.  In a terminal window or Jupyter notebook cell, type:
# ```
# ! python -m pip install lightkurve --upgrade
# ```
# 
# See our [installation instructions](about/install.rst) page for details and troubleshooting information.
# 
# With Lightkurve installed, it is easy to extract brightness time series data (astronomers call this a *light curve*)
# from the tiny images of stars collected by NASA's Kepler and TESS planet-hunting telescopes.
# 
# For example, let's download and display the pixels of a famous star named [KIC 8462852](https://en.wikipedia.org/wiki/KIC_8462852), also known as *Tabby's Star* or *Boyajian's Star*, which is known to show unusual light fluctuations.
# 
# First, we start Python and use the `search_targetpixelfile` function to obtain the Kepler pixel data for the star  from the [data archive](https://archive.stsci.edu/kepler/):

# In[ ]:


from lightkurve import search_targetpixelfile
pixelfile = search_targetpixelfile("KIC 8462852", quarter=16).download();


# Next, let's display the first image in this data set:

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pixelfile.plot(frame=1);


# It looks like the star is an isolated object, so we can extract a light curve by simply summing up all the pixel values in each image:

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lc = pixelfile.to_lightcurve(aperture_mask='all');


# The above method returned a `LightCurve` object which gives us access to the number of photons received by the spacecraft over time (known as the *flux*).  The time is an [AstroPy Time object](https://docs.astropy.org/en/stable/time/) in units of *days*:

# In[ ]:


lc.time


# The flux is an [AstroPy Quantity object](https://docs.astropy.org/en/stable/units/) in units *electrons/second*:

# In[ ]:


lc.flux


# We can plot these data using the `plot()` method:

# In[ ]:


lc.plot();


# The plot reveals a short-lived 20% dip in the brightness of the star.  It looks like we re-discovered one of the [intriguing dips in Tabby's star](https://en.wikipedia.org/wiki/KIC_8462852#Luminosity).
# 
# Congratulations, you are now able to make new discoveries in Kepler and TESS data!
# 
# Next, head to our [tutorials section](https://docs.lightkurve.org/tutorials) to be guided through more detailed examples of carrying out science with Lightkurve!