Star Copper Congratulates Doubleview Gold's Mineral Resource Estimate Boosting Interest Across Entire Region

--Company Advances Plans for Mineral Resource Estimate at Star Property in 2026

VANCOUVER, BC / ACCESS Newswire / February 26, 2026 / Star Copper Corp.(CSE:STCU)(OTCQX:STCUF)(FWB:SOP) ("Star Copper" or the "Company"), a critical mineral exploration and development company, is pleased to congratulate Doubleview Gold Corp. (TSXV:DBG) on the announcement of its updated Mineral Resource Estimate for the Hat polymetallic porphyry project in northwestern British Columbia.

Doubleview's recently announced updated estimate outlines 609 million tonnes of Measured and Indicated Mineral Resources grading 0.43% copper equivalent, containing approximately 5.82 billion pounds of copper equivalent, along with a further 503 million tonnes of Inferred Mineral Resources grading 0.41% copper equivalent containing approximately 4.57 billion pounds copper equivalent.

Star Copper's CEO, Darryl Jones states "This is a huge update for our neighbour, and we are very excited to be a part of this emerging district, as Star is accelerating drilling at the Star Property to expand and better define mineralized zones, strengthening the geological model and advancing the project toward future resource-stage evaluation. With an aggressive 2026 drill program already planned and a number of 2025 drill results still pending, the company is positioned to take advantage of the recent surge in metals sector prices to fill the growing need for resource development.

Star recognizes the significance of advancing large-scale porphyry systems in British Columbia and commends Doubleview's technical team for their disciplined and targeted drilling efforts that have steadily expanded the Hat deposit footprint. The recently announced Hat Project MRE is positioned approximately 5km to the southeast of the Star Property (See Figure 1).

Hat Project Updated Mineral Resource Estimate - Doubleview Gold Corp - News Release Feb 25, 2026

Table 1: Hat MRE at a 0.2% CuEq Cut‑Off Effective February 4, 2026,
(Base‑Case Scenario to be Presented in the Technical Report)

Table 2: Hat MRE at a 0.2% CuEq Cut-Off as of February 4, 2026, Scandium Oxide Resources

Notes:

¹ Scandium tonnages represent 12.5% of the mineralized material by category, reflecting the proportion of tailings expected to be processed through a dedicated scandium leach circuit under current metallurgical design constraints.

² Scandium oxide metal content have been calculated using the metallurgical recovery of 72% and conversion factor from Sc to Sc₂O₃ of 1.534.

• Mineit's Qualified Person, Tomasz Wawruch, FAusIMM, completed the MRE, and has reviewed and approved the technical disclosure related to the MRE contained in this news release. Mr. Wawruch is a senior geology and mineral resource consultant independent of Doubleview. Gilles Arseneau, PhD., P.Geo., of ARSENEAU Consulting Services Inc., provided an independent review of this MRE.

• Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.

• The estimate of Mineral Resources may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant issues.

• Inferred Mineral Resources are considered too speculative geologically to have economic considerations applied to them that would enable them to be categorized as Mineral Reserves.

• The Mineral Resource Estimate was prepared in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum ("CIM") Definition Standards for Mineral Resources and Mineral Reserves (2014), and CIM MRMR Best Practice Guidelines (2019).

• The effective date of the MRE is February 4, 2026.

• Metal contents have been calculated using the following metallurgical recovery factors: Cu = 85%, Au = 89%, Co = 78%, and Ag = 68%.

• Economic assumptions used include US$4.80/lb Cu, US$20.00/lb Co, US$3,200/oz Au, US$46/oz Ag, and a 2% NSR royalty.

• Mineral Resources are reported within optimized open pit constraints and 0.2% CuEq cut-off grade, based on a C$7.93/t milled processing cost and C$2.90/t milled general and administrative cost, with a mining cost of C$3.01/t plus incremental mining cost increasing by C$0.015/t for every bench below the reference level of 1,125 mRL.

• CuEq calculations do not include scandium. The formula used to calculate CuEq is: CuEq = [(((Ag × 46.0 × 0.68)/31.1035) + ((Au × 3200 × 0.89)/31.1035) + 0.0001 × (Co × 20.0 × 0.78 × 22.0462) + 0.0001 × (Cu × 4.8 × 22.0462 × 0.85))/(4.8 × 22.0462 × 0.85)], where all input variables are expressed in (ppm) and CuEq is expressed in percent (%).

• Rounding may result in minor variations between individual values and totals; such differences are not considered material to the MRE.

• Mineral Resource classification reflects the level of geological confidence and satisfies the uncertainty criteria appropriate for exploration and resource development. Additional drilling will be required to reduce uncertainty to the level expected for production planning.

• The MRE reflects the geological interpretation, drill-hole spacing, and estimation parameters available at the time of modelling. Any additional drilling is expected to influence the current outcome by improving confidence in the estimates and refining the geometry of the mineralized domains.

• The Mineral Resource results are presented in situ within the optimized pit. Mineralized material outside the pit has not been considered as a part of the current MRE tabulation. Calculations used metric units (metres, tonnes, g/t).

• A total of 97 diamond drill holes, comprising 49,548 m of core, were incorporated into the Mineral Resource Estimate. All drilling data used in the MRE were subject to standard QA/QC validation prior to inclusion.

• The block model is defined relative to a model origin at UTM Zone 9N 346,750 E / 6,453,000 N / 0 (NAD 83). Parent blocks measure 15â€¯× 15â€¯× 15 m, totalling 136 × 150 × 75 blocks across extents of 2,040 m (X), 2,250 m (Y), and 1,125 m (Z). All volumes and estimates are constrained by these discretization parameters.

The scientific and technical information relating to Doubleview Gold Corp.'s Hat Project mineral resource estimate has been derived from publicly available disclosure by Doubleview Gold Corp. Star Copper Corp. has not independently verified the technical information contained in such disclosure, and a Qualified Person on behalf of Star Copper has not reviewed or validated the underlying data or methodology supporting the Hat Project mineral resource estimate. Accordingly, Star Copper makes no representation as to the accuracy or completeness of this information. The mineralization hosted on the Hat Project is not necessarily indicative of mineralization on the Company's Star Property.

The golden triangle of British Columbia continues to demonstrate its strength as an outstanding globally competitive jurisdiction for copper-gold development, and projects such as Hat highlight the long-term opportunity for regional critical minerals opportunities including copper, gold, cobalt and scandium within the province.

Star remains focused on advancing its copper-gold assets and believes that continued technical success across the region strengthens investor awareness of the scale and potential of British Columbia's porphyry districts.

Qualified Person

Jeremy Hanson, P. Geo., a Qualified Person as that term is defined under NI 43-101, is a non-independent contractor of the Company and has reviewed and approved the technical aspects of this news release.

On Behalf of the Board of Directors

~Darryl Jones~

Darryl Jones
CEO, President & Director
Star Copper Corp.

About Star Copper Corp. (CSE:STCU)(OTCQX:STCUF)(FWB:SOP / WKN A416ME)

Star Copper Corp. is a Canadian mineral exploration company focused on the discovery and advancement of large-scale copper-gold systems in British Columbia. The Company's flagship Star Project is located in British Columbia's prolific Golden Triangle and hosts multiple high-priority targets and exhibits geological characteristics consistent with significant porphyry copper deposits (watch our videos: https://starcopper.com/media/). The project hosts multiple copper-gold porphyry-style targets, including Star Main, Star North, East & West, Copper Creek and Copperline. Significant exploration including historical drilling has confirmed open mineralization at depth and in all directions. Star Copper's strategic plans include geological mapping and geophysical surveys to refine existing targets, diamond drilling programs to test high-priority zones, environmental baseline studies and permitting groundwork alongside data analysis and resource modeling to support a future resource estimate prepared in accordance with NI 43-101. The Company further plans to advance its Indata Project with follow-up drilling to expand on previous high-grade copper and gold intercepts, trenching and surface sampling to delineate mineralized zones, and infrastructure improvements for site accessibility and operations. With a commitment to sustainable development and value creation, Star Copper aims to position itself to support surging industrial demand to meet growing global electrification needs.

For more information visit: www.starcopper.com, watch our videos at https://starcopper.com/media/, and while you are there, sign up for free news alerts at https://starcopper.com/news/news-alerts/, or follow us on X (formerly Twitter),Facebook or LinkedIn. More information in respect of the project, including historical drilling, is available under the Company's profile at www.sedarplus.ca and/or in the Company's February 26, 2025 technical report.

Investor Relations
Star Copper Corp.
Email: info@starcopper.com
Web: https://starcopper.com/

Quality Control and Quality Assurance

Mr. Mike Ostenson, P.Geo., is the qualified person for the purposes of National Instrument 43-101, and he has reviewed and approved the technical disclosure contained in this news release. Mr. Ostenson is a Geologist at Stillwater and is not independent of the Company.

Cautionary Note Regarding Forward-Looking Statements

This news release contains forward-looking statements and other statements that are not historical facts. Forward-looking statements are often identified by terms such as "will", "may", "should", "anticipate", "expects" and similar expressions. All statements other than statements of historical fact, included in this news release are forward-looking statements that involve risks and uncertainties. Forward-looking statements in this press release include, but are not limited to, statements regarding exploration of the Company's flagship Star Project and the potential thereof, as well as the anticipated mineral resource estimate planned in respect of the Star Project. There can be no assurance that such statements will prove to be accurate and actual results and future events could differ materially from those anticipated in such statements. Important factors that could cause actual results to differ materially from the Company's expectations include, but are not limited to, the early-stage nature of the Star Project, the inherently unpredictable nature of resource exploration, market conditions and the risks detailed from time to time in the filings made by the Company with securities regulators. The reader is cautioned that assumptions used in the preparation of any forward-looking information may prove to be incorrect. Events or circumstances may cause actual results to differ materially from those predicted, as a result of numerous known and unknown risks, uncertainties, and other factors, many of which are beyond the control of the Company. The reader is cautioned not to place undue reliance on any forward-looking information. Such information, although considered reasonable by management at the time of preparation, may prove to be incorrect, and actual results may differ materially from those anticipated. The forward-looking statements contained in this news release are made as of the date of this news release and the Company will update or revise publicly any of the included forward-looking statements as expressly required by applicable law. Forward-looking statements contained in this news release are expressly qualified by this cautionary statement.

SOURCE: Star Copper Corp.