Incorrect reading of multi-line Explanations in MRT/CDS ReadMes

[jobovy]

Description

I'm trying to read this table (Table 1 from this paper) using astropy.io.ascii and this fails with

ValueError: Unknown data type ""times"" for column "critical"

This error points to a multi-line Explanation in the ReadMe being read wrong. This seems to happen because the first non-whitespace character in the second line is a number (the line is " 200 times the critical density"), because just adding a letter in front of the 200 lets the table be read. It seems like what's happening is that the parser thinks the line is a new column because it starts with a number.

Expected behavior

Read the table without error

How to Reproduce

Download the table:

curl -O "https://content.cld.iop.org/journals/0004-637X/958/1/62/revision1/apjacfaebt1_mrt.txt?Expires=1700495421&Signature=SIYhtzfO-4l4Dl29Ojz8F5dbTWg4M29Wl35YY18F2gcruZmr2KqVJsMIyFeq7HducHiWBnGwxhun3idcK5yEDRz67iyFmxSxx-60oM4h7W6uNQTqXpvW9zuTMhsaGSSumQTXttKsfMYIClooDDefUYWWHrV0KQGfvSAIfARmo5BW8F3iQciDVhoBS-VdsOt6yky306fZfFUZz7SMreNfz3cSANVwX~LKJQKmy0NK8yAT8zLc7bppPWK6CkzORdI0MZ-EWHyZI~ktOe9aZhDJ-NKLaDymFkqJ3xTggUVcrLBrb~CnfxI4hsQ34TXnMclVrrd7GAvGWLj~Df8JA2zWPA__&Key-Pair-Id=KL1D8TIY3N7T8"

then open Python and do

from astropy.io import ascii
tab= ascii.read("apjacfaebt1_mrt.txt",format='cds')

Versions

macOS-14.0-arm64-arm-64bit
Python 3.10.6 | packaged by conda-forge | (main, Aug 22 2022, 20:38:29) [Clang 13.0.1 ]
astropy 5.3.4
Numpy 1.25.0
pyerfa 2.0.0.1
Scipy 1.11.0
Matplotlib 3.7.1