<p>What's more, the Neupert effect is often stated that the hard X-rays look like the time derivative of the soft X-rays.  The physical significance of that is it suggests that the presence of hard X-rays relates directly to the energization of soft X-ray gas.  It supports the common model that hard X-rays are a byproduct of particle acceleration, and the accelerated particles deposit heat that gradually leaks out as soft X-rays.</p>

CC BY-SA 4.0
2018-12-26T16:35:36.367Z
2018-12-26T16:35:36.367Z
Ken G
<p>The Neupert Effect describes the commonly observed phenomenon that hard X-rays occur predominantly during the rise phase of soft X-rays during a solar flare, as illustrated by the graph below:</p>

<p><img src="https://i.sstatic.net/4tw1y.gif" alt="Neupert Effect during a flare observed by Yohkoh"></p>

<p>In the graph, the first peak is that of the hard X-rays, which you can see occurs during the rise of the other line which represents the soft X-rays.</p>

<p><strong>Source:</strong></p>

<ul>
<li><a href="http://solar.physics.montana.edu/nuggets/1998/981016/981016.html" rel="noreferrer">The Neupert Effect - Solar Physics at Montana State University</a></li>
</ul>

CC BY-SA 4.0
2013-10-08T13:58:50.323Z
2018-12-26T12:19:30.293Z
2018-12-26T12:19:30.293Z
called2voyage
<p>This effect is frequently discussed in the context of solar time series. In particular, it a relationship between soft x-ray (thermal emission) and hard x-ray (nonthermal emission) from the Sun.</p>

<the-sun>
What is the Neupert Effect?
ehsteve
# What is the Neupert Effect?

(Asked by: username_0 on 2013-10-08)

This effect is frequently discussed in the context of solar time series. In particular, it a relationship between soft x-ray (thermal emission) and hard x-ray (nonthermal emission) from the Sun.

**Tags:** the-sun


---

## 2 answers

### Answer by username_2 on 2013-10-08. Score: 16 | Accepted answer

The Neupert Effect describes the commonly observed phenomenon that hard X-rays occur predominantly during the rise phase of soft X-rays during a solar flare, as illustrated by the graph below:

![Neupert Effect during a flare observed by Yohkoh](https://i.sstatic.net/4tw1y.gif)

In the graph, the first peak is that of the hard X-rays, which you can see occurs during the rise of the other line which represents the soft X-rays.

**Source:**

* [The Neupert Effect - Solar Physics at Montana State University](http://solar.physics.montana.edu/nuggets/1998/981016/981016.html)


---

### Answer by username_1 on 2018-12-26. Score: 2

What's more, the Neupert effect is often stated that the hard X-rays look like the time derivative of the soft X-rays. The physical significance of that is it suggests that the presence of hard X-rays relates directly to the energization of soft X-ray gas. It supports the common model that hard X-rays are a byproduct of particle acceleration, and the accelerated particles deposit heat that gradually leaks out as soft X-rays.


---

