It was another busy week for Australia's top brokers. This has led to the release of a number of broker notes.

Three broker buy ratings that you might want to know more about are summarised below. Here's why brokers think these ASX shares are in the buy zone:

Northern Star Resources Ltd (ASX: NST)

According to a note out of Goldman Sachs, its analysts have retained their buy rating on this gold miner's shares with a trimmed price target of $22.10. Goldman notes that Northern Star's production fell short of expectations during the third quarter due to the underperformance of the KCGM operation. However, while higher than consensus estimates, Goldman was pleased that its cash costs were broadly in line with its own estimates. Looking beyond this quarter, the broker remains very positive on the gold miner, highlighting its production growth as reasons to buy. Goldman points out that the expanded KCGM operations and other asset growth are taking group production toward ~2Mozpa from ~2027-29+ (and up to ~2.6Moz with the acquisition of De Grey Mining). The Northern Star share price ended the week at $19.17.

ResMed Inc. (ASX: RMD)

Another note out of Goldman Sachs reveals that its analysts have retained their conviction buy rating on this sleep disorder treatment company's shares with an improved price target of $49.30. This followed the release of ResMed's quarterly update late last month, which was broadly in line with Goldman's expectations. It notes that it was particularly pleased with the company's gross margin, which grew ~70bps sequentially and met the top end of management's guidance. Another positive was confirmation from the US Government that its medical devices are largely exempt from tariffs. All in all, Goldman remains very positive on the company and feels that its shares are undervalued at current levels. Especially given its forecast for earnings per share to grow at a compound annual growth rate of 17% between FY 2024 and FY 2027. The ResMed share price was fetching $37.26 at Friday's close.

Woolworths Group Ltd (ASX: WOW)

Analysts at Goldman Sachs have also retained their buy rating on this supermarket giant's shares with an increased price target of $36.50. According to the note, Goldman was pleased with Woolworths' performance during the third quarter. The broker points out that the company's sales were largely in line with estimates. This includes Australia Food sales being up 3.6% and comfortably ahead of industry growth rates for the period. Outside this, its analysts are expecting a strong recovery in both sales and earnings in FY 2026. So much so, Goldman is forecasting group sales growth of 4% and EBIT growth of 20% for the next financial year. As a result, it thinks the company's shares are good value at current levels. The Woolworths share price ended the week at $32.68.