User:Brianphelan

Initial Discovery
Formaldehyde was first discovered in 1969 by L. Snyder et al. using the National Radio Astronomy Observatory. H2CO was detected by means of the 111 - 110 ground state rotational transition at 4830 Mhz [1].

Subsequent Discoveries
Formaldehyde was the first polyatomic organic molecule detected in the interstellar medium and since its initial detection has been observed in many regions of the galaxy [2]. The isotopic ratio of [12C]/[13C] was determined to be about or less than 50% in the galactic disk [3]. Formaldehyde has been used to map out kinematic features of dark clouds located near Gould's Belt of local bright stars [4]. In 2007, the first H2CO 6 cm maser flare was detected [7]. It was a short duration outburst in IRAS 18566 + 0408 that produced a line profile consistent with the superposition of two Gaussian components, which leads to the belief that an event outside the maser gas triggered simultaneous flares at two different locations [7]. Although this was the first maser flare detected, H2 masers have been observed since 1974 by Downes and Wilson in NGC 7538 [8]. Unlike OH, H2O, and CH3OH, only five galactic star forming regions have associated formaldehyde maser emission, which has only been observed through the 110 → 111 transition [8].