Orion's Belt Stars (l to r)
Alnitak (zeta Orionis)
Alnilam (epsilon Orionis)
Mintaka (delta Orionis)


Photometry General

Bright Star Photometry Techniques

Spectroscopy General

Bright Star Spectroscopy Techniques

Photometric Bands and Spectral Lines


Photometrty and Spectroscopy Reports (New)

Orion Project Stars
Low-Resolution Wavelength
Calibrated Line Profiles

Project Stars

Please try to observe one or more of these stars as often as you can

(alpha Orionis)

Spectral Class: M2Iab

Spectroscopy Showcase

(beta Orionis)
Spectral type: B8Iae

Spectroscopy Showcase


(delta Orionis)

Spectral type: O9.5 II

Spectroscopy Showcase

(epsilon Orionis)

Spectral Class: BOla

Spectroscopy Showcase

(zeta Orionis)

Spectral Class:
a component:
O9.7 Ibe
b component: O9v

Spectroscopy Showcase


Spectral Class:
B0.5 iab

Spectroscopy Showcase


Orion Project
SAS Paper
pdf 3.3 MB

Orion Project
SAS Presentation
ppt 30 MB

2014 SAS Meeting Pictures



Orion, the hunter, is one of the most famous constellations. Its declination is such that it is visible from most of the civilized world. In addition, most of the stars of Orion are very bright and interesting. Originally this Project was called the Betelgeuse Campaign. Because Campaigns usually have a defined end and this is an on going Project and also now includes three more stars of Orion, the name was changed to the Orion Project. This is a developing Project and comments and suggestions are welcome. We all have something to learn and contribute.

To provide a focal point for discussions a Orion Project Forum was created. To join the Forum please use the following email address to subscribe.

NOTE: This is not a Citizen Science type project. Observers must be willing to use the proper equipment and develop the necessary skills to produce quality data. This Project presents an opportunity to both learn photometry and/or spectroscopy or sharpen your skills while contributing valuable data. This is Discovery Science and an on going Project.

Betelgeuse (alpha Orionis) is one of the brightest stars in Orion and the eighth brightest star in the sky and sometimes even brighter than Rigel (beta Orionis), the lower right star of Orion). Betelgeuse is the big bright reddish orange star in the upper left of the constellation.

Both Betelgeuse and Rigel as well as the right most star in Orion's belt Mintaka (delta Orionis) along with the middle star in Orion's belt, Alnilam (epsilon Orionis), the left most star Alnitak (zeta Orionis) and Saiph (kappa Orioins) the lower left foot of Orion have been designated as stars of interest for photometry and spectroscopy. Observers are encouraged to take photometric and/or spectroscopic data on one or more of these stars and report the results to the Project.

Note: Saiph has been added to the Orion Projet stars as of December 2014.

There are two main objectives.
The first objective is to help the observer produce quality photometric and spectroscopic data. Since these stars are bright and easy to find, many will think they are easy to observe. For photometry they present a large challenge because they are bright. Doing photometry on these stars will require special techniques and care. For spectroscopy, these are actually easier stars to work with because they are bright. Short exposures will allow easy experimentation to develop good techniques and obtain good spectra. This project is an excellent means to learn more about photometry and spectroscopy.

The second objective is to produce archival quality photometric and spectroscopic data as indicated below.

UBVRIJH Band Photometry
SSP-3 BVRI (Primarily BV)
CCD BVRI (Primarily BV)
Photon Counting UBV

For the SSP-3 and CCD the BV filters should be sufficient as the RI can be a problem with the transformation.


While DSLR can be used, it is not recommended as the dynamic range is low and only the V band can be used. An inexpensive monochrome CCD camera (e.g., the Orion StarShoot G3 Monochrome camera $399) coupled with a 50 mm or 28 mm camera lines and BV filters is ideal.

High, Mid and Low-Resolution Spectroscopy
Lhires III (2400 l/mm grating)
ALPY 600
Star Analyser

Some of these stars produce emission lines that randomly pop up. Low-resolution spectroscopy may find those and alert others to investigate with high-resolution spectroscopy. Low-resolution work is encouraged and can prove valuable.

It seems every so often professionals start a Campaign on one or more of these stars. Many times small observatories only hear of the Campaign when it is over or just starting giving little time if any to prepare. Because of this, the basic purpose of this Project is to continue photometric and spectroscopic observations of these stars. This will provide continuous observational data for the stars.

1. To help beginners do photometry and spectroscopy and get to the point where good data is submitted that can be scientifically useful. The means transformed and extinction corrected photometric data that is consistent and close to what others are producing for the same time. For spectroscopy beginners will be mentored to the point of being able to submit high-quality wavelength calibrated line profiles.

2. Data will be archived and available to anyone. For spectroscopy. A showcase of wavelength calibrated spectral line profiles in .Jpg format will be shown. Corresponding line profile .Dat files will be archived. Photometric data will be archived and periodically submitted to the AAVSO.


Longtime and continuous observations producing high-quality photometric and spectroscopy data of the program stars.

This web site will be developed and devoted to the project. The Hopkins Phoenix Observatory will maintain the site.

Photometric data will be listed on the web site as well as archived with the AAVSO.

Wavelength-calibrated spectroscopic line profiles will be showcased on the site and .Dat files of the profiles and raw image fits files will be archived on the web site.

Comments and suggestions are most welcome.

To join the Project and for more information, comments or questions, please send an email to Jeff Hopkins at phxjeff@hposoft.com


Check the Photometry Pages for magnitude plots

Article in the September issue of Sky & Telescope in the Letters section on page 8.



Created 26 July 2012
24 January 2015

Web Master HPOSOFT