In this work we utilise the most recent publicly available type Ia supernova ( SN Ia ) compilations and implement a well formulated cosmological model based on Lemaître-Tolman-Bondi metric in presence of cosmological constant \Lambda ( \Lambda LTB ) to test for signatures of large local inhomogeneities at z \leq 0.15 .
Local underdensities in this redshift range have been previously found based on luminosity density ( LD ) data and galaxy number counts .
Our main constraints on the possible local void using the Pantheon SN Ia dataset are : redshift size of z _ { size } = 0.068 ^ { +0.021 } _ { -0.030 } ; density contrast of \delta \Omega _ { 0 } / \Omega _ { 0 } = -10.5 _ { -7.4 } ^ { +9.3 } \% between 16th and 84th percentiles .
Investigating the possibility to alleviate the \sim 9 \% disagreement between measurements of present expansion rate H _ { 0 } coming from calibrated local SN Ia and high- z cosmic microwave background data , we find large local void to be a very unlikely explanation alone , consistently with previous studies .
However , the level of matter inhomogeneity at a scale of \sim 100Mpc that is allowed by SN Ia data , although not expected from cosmic variance calculations in standard model of cosmology , could be the origin of additonal systematic error in distance ladder measurements based on SN Ia .
Fitting low-redshift Pantheon data with a cut 0.023 < z < 0.15 to the \Lambda LTB model and to the Taylor expanded luminosity distance formula we estimate that this systematic error amounts to 1.1 \% towards the lower H _ { 0 } value .
A test for local anisotropy in Pantheon SN Ia data yields null evidence .
Analysis of LD data provides a constraint on contrast of large isotropic void \delta \Omega _ { 0 } / \Omega _ { 0 } = -51.9 \% \pm 6.3 \% , which is in \sim 4 \sigma tension with SN Ia results .
More data are necessary to better constrain the local matter density profile and understand the disagreement between SN and LD samples .