<p>Based on a few stars that I recognize (omicron Ceti, R Aqr) the period is in units of days. The period for these types of stars is often on the order of one year.</p>
<p>The precision is misleading. I assume the high &quot;precision&quot; is based on the number of days divided by multiple cycles; in other words, it is a long term average. The period for individual cycles will vary.</p>

CC BY-SA 4.0
2021-09-07T16:15:32.330Z
2021-09-07T16:15:32.330Z
JohnHoltz
<p>The <a href="https://www.aavso.org/aavso-binocular-program" rel="nofollow noreferrer">AAVSO website</a> has a page for observers with binoculars. On this page, there is a table with stars of interest, and the period of each variable is indicated. However, the unit for the period is not.</p>
<p>First line of the table:</p>
<blockquote>
<p>Name  N/S     AUID    Coords  Const   Type    Period  Mag     Min FOV/ Lim Mag</p>
<p>EG  And   North   000-BBC-010     00 44 37.19     And     ZAND+E  482.57  6.97 - 7.8 V    180 arcmin/ 9.5</p>
</blockquote>
<p>So EG And has a period of 482.57. But what is the unit for the period?</p>

<variable-star>
What is the unit for durations on the AAVSO website?
usernumber
# What is the unit for durations on the AAVSO website?

(Asked by: username_0 on 2021-09-07)

The [AAVSO website](https://www.aavso.org/aavso-binocular-program) has a page for observers with binoculars. On this page, there is a table with stars of interest, and the period of each variable is indicated. However, the unit for the period is not.

First line of the table:

> Name N/S AUID Coords Const Type Period Mag Min FOV/ Lim Mag
>
> EG And North 000-BBC-010 00 44 37.19 And ZAND+E 482.57 6.97 - 7.8 V 180 arcmin/ 9.5

So EG And has a period of 482.57. But what is the unit for the period?

**Tags:** variable-star

---

## 1 answers

### Answer by username_1 on 2021-09-07. Score: 1 | Accepted answer

Based on a few stars that I recognize (omicron Ceti, R Aqr) the period is in units of days. The period for these types of stars is often on the order of one year.

The precision is misleading. I assume the high "precision" is based on the number of days divided by multiple cycles; in other words, it is a long term average. The period for individual cycles will vary.


---

