A low-cost revolution in stellar spectroscopy

Let everyone
read the language of starlight

A low-cost objective-prism stellar spectroscopy rig that captures professional-grade stellar spectra for under ¥1000. Upload your raw data and the analysis pipeline returns the star’s spectral type, temperature, mass and more.

~¥1000
total cost
350-900
nm spectral range
7
stellar classes

About the project

Breaking the high-cost barrier of spectroscopic astronomy and making public stellar observation and research accessible to everyone

Solving the cost problem
Conventional spectrographs cost hundreds of thousands of yuan; this project achieves viable stellar spectroscopy for around ¥1000
Objective-prism design
A 15° circular prism: the simplest design with 100% light throughput, putting all collected light into the image
Automated classification
A dedicated classification model that automatically identifies stellar spectral types using the Harvard classification scheme
Equipment & specifications

Core hardware setup

3D-printed mounting frame + amateur astronomy gear

Technical specifications
Spectrograph type
Objective prism
Prism apex angle
15°
Prism diameter
60 mm
Prism cost
~¥200 each
Telescope
105/f7 refractor
Mount
EQ6-Pro
Camera
QHYCCD MiniCAM8M
Sensor
SONY IMX585 CMOS
Pixel size
2.9 μm
Sensor size
11.18 x 6.32 mm
Spectral range
350 - 900 nm
Total cost
~¥1000
Comparing three spectrograph approaches
Why we chose the objective prism
Objective prismOur choice
Cost
~¥1000
Complexity
Low
Throughput
High
PGP spectrograph
Cost
>¥5000
Complexity
Medium
Throughput
Low
Fiber spectrograph
Cost
>¥100,000
Complexity
High
Throughput
Low
Data processing pipeline

From raw video to stellar data

Raw captures pass through a series of processing steps that ultimately output usable astronomical information

01

Frame stacking

Stack video frames to reduce noise and extract the spectrum image

02

Rotate & align

Rotate the spectrum to horizontal, then crop and precisely align

03

Spectrum extraction

Extract the 1-D spectral curve and calibrate wavelength

04

Classification

Identify spectral type and parameters via Harvard classification

Results

Sample captured spectra

Dozens of stellar spectra successfully captured and classified with this device

Vega

Prominent hydrogen Balmer series

A0V9602 K

Altair

Typical A-type main-sequence spectrum

A7V7550 K

Arcturus

Red giant with TiO absorption bands

K1.5III4286 K

Betelgeuse

Red supergiant, strong molecular bands

M1-2Ia3500 K

Capella

Yellow giant binary system

G8III4970 K

Sirius

Brightest star in the night sky

A1V9940 K

Start your spectroscopy journey

Upload the raw spectrum data you captured with this device, and the system will automatically analyze it and output the star’s information

StarSpectra

The Experimental High School Attached to Beijing Normal University · Li Yiyang, Yang Yuanhe · Advisor: He Dao