We investigate the environment of the very low-luminosity object L1521FÂ IRS using data from the Taurus Spitzer Legacy Survey .
The MIPS 160 µm image shows both extended emission from the Taurus cloud as well as emission from multiple cold cores over a 1 \arcdeg \times 2 \arcdeg region .
Analysis shows that the cloud dust temperature is 14.2 \pm 0.4 K and the extinction ratio is A _ { 160 } / A _ { K } = 0.010 \pm 0.001 up to A _ { V } \sim 4 mag .
We find \kappa _ { 160 } = 0.23 \pm 0.046 ~ { } cm ^ { 2 } ~ { } g ^ { -1 } for the specific opacity of the gas-dust mixture .
Therefore , for dust in the Taurus cloud we find the 160 µm opacity is significantly higher than that measured for the diffuse ISM , but not too different from dense cores , even at modest extinction values .
Furthermore , the 160 µm image shows features that do not appear in the IRAS 100 µm image .
We identify six regions as cold cores , i.e .
colder than 14.2 K , all of which have counterparts in extinction maps or C ^ { 18 } O maps .
Three of the six cores contain embedded YSOs , which demonstrates the cores are sites of current star formation .

We compare the effects of L1521F IRS on its natal core and find there is no evidence for dust heating at 160 or 100 µm by the embedded source .
From the infrared luminosity L _ { TIR } = 0.024 ~ { } L _ { \sun } we find L _ { bol\ _ int } = 0.034 - 0.046 ~ { } L _ { \sun } , thus confirming the source ’ s low-luminosity .
Comparison of L1521FÂ IRS with theoretical simulations for the very early phases of star formation appears to rule out the first core collapse phase .
The evolutionary state appears similar to or younger than the class 0 phase , and the estimated mass is likely to be substellar .