Aldebaran Reports 513 m of 1.06% CuEq (1.01% Cu, 0.08 g/t Au & 3.58 g/t Ag), Within 1,257.30 m of 0.66% CuEq (0.62% Cu, 0.05 g/t Au & 1.94 g/t Ag) at the Altar Copper-Gold Project in San Juan, Argentina

Also reports
1,323.20 m of 0.50% CuEq¹, including 555 m of 0.71% CuEq¹
and
939.30 m of 0.58% CuEq¹, including 420.30 m of 0.76% CuEq¹
and
1,354 m of 0.41% CuEq¹, including 162 m of 0.61% CuEq¹
and
1,336 m of 0.38% CuEq¹, including 124 m of 0.69% CuEq¹

VANCOUVER, British Columbia, Sept. 09, 2026 (GLOBE NEWSWIRE) -- Aldebaran Resources Inc. (“Aldebaran” or the “Company”) (TSX-V: ALDE, OTCQX: ADBRF) is pleased to provide results of six holes from the 2025-2026 infill and geotechnical drilling program at the Altar project in San Juan, Argentina. The goal of these holes was to upgrade resource blocks classified as Inferred to the Measured & Indicated categories and in some cases, also for geotechnical purposes.

Highlights

ALD-26-267

1,257.30 m of 0.66% CuEq¹from 135.70 m depth
- Including 513 m of 1.06% CuEq¹ from 514 m depth
  - Including 214 m of 1.57% CuEq¹from 520 m depth

ALD-26-261

1,323.20 m of 0.50% CuEq¹from 157 m depth
- Including 802.20 m of 0.64% CuEq¹ from 678 m depth
  - Including 555 m of 0.71% CuEq¹from 816 m depth
    - Including 58 m of 0.94% CuEq¹ from 818 m depth

ALD-25-262

939.30 m of 0.58% CuEq¹ from 368 m depth
- Including 763.30 m of 0.65% CuEq¹ from 544 m depth
  - Including 420.30 m of 0.76% CuEq¹from 887 m depth
    - Including 204.30 m of 0.84% CuEq¹ from 1,103 m depth

ALD-26-182EXT

1,354 m of 0.41% CuEq¹from 56 m depth
- Including 107 m of 0.61% CuEq¹from 646 m depth
- and 162 m of 0.61% CuEq¹from 893 m depth

ALD-26-263

1,336 m of 0.38% CuEq¹ from 213 m depth
- Including 124 m of 0.69% CuEq¹ from 670 m depth

¹For individual assays for all metals, see Table 1

John Black, Chief Executive Officer of Aldebaran, commented: “Today’s drill results are a reminder of the impressive scale of Altar’s high-grade cores and the significant size of the project. Looking ahead, the upcoming mineral resource estimate, expected in October of this year, will establish the foundation for the pre-feasibility study expected in Q2/Q3 2027.”

Kevin B. Heather, Chief Geological Officer of Aldebaran, commented: “Many of these reported holes were oriented drill holes designed for geotechnical purposes; however, they were also designed to provide essential infill data for resource category conversion from Inferred to Indicated and Measured for the upcoming mineral resource estimate. The oriented drill holes also allow us to better understand and constrain the orientations in 3D-space of lithological contacts, faults, fractures, and veins; all of which enhance our geological model for the upcoming resource estimate and form the basis for both the open pit and potential underground designs in the PFS mine plan.”

Table 1 below shows detailed assays for all six holes. Figure 1 displays a plan map of the completed drill hole locations, while Figures 2 to 7 display cross sections of the holes reported herein. Holes with the suffix EXT are extensions of previously drilled holes.

Table 1 – Altar Drill Hole Results
	From (m)	To (m)	Interval (m)	Cu (%)	Au (g/t)	Ag (g/t)	Mo (ppm)	As (ppm)	CuEq (%)
ALD-26-182EXT - Total Depth - 1,410 m
Interval	56.00	1,410.00	1,354.00	0.37	0.10	1.60	27	219	0.41
Incl.	646.00	753.00	107.00	0.52	0.20	2.97	42	513	0.61
And	893.00	1,055.00	162.00	0.55	0.12	1.74	29	70	0.61
ALD-26-261 - Total Depth - 1,480.20 m
Interval	157.00	1,480.20	1,323.20	0.46	0.05	2.09	93	308	0.50
Incl.	678.00	1,480.20	802.20	0.58	0.05	2.71	140	276	0.64
Incl.	816.00	1,371.00	555.00	0.64	0.05	2.37	149	178	0.71
Incl.	818.00	876.00	58.00	0.86	0.08	1.72	200	132	0.94
ALD-26-262 - Total Depth - 1,307.30 m
Interval	368.00	1,307.30	939.30	0.53	0.05	1.67	122	252	0.58
Incl.	544.00	1,307.30	763.30	0.60	0.03	1.93	149	265	0.65
Incl.	640.00	825.00	185.00	0.58	0.06	1.15	103	351	0.62
And	887.00	1,307.30	420.30	0.69	0.02	2.66	204	238	0.76
Incl.	1,103.00	1,307.30	204.30	0.77	0.01	3.15	231	107	0.84
And	1,237.00	1,307.30	70.30	0.74	0.00	3.31	294	53	0.82
ALD-26-263 - Total Depth - 1,549 m
Interval	213.00	1,549.00	1,336.00	0.34	0.08	1.49	30	208	0.38
Incl.	670.00	794.00	124.00	0.59	0.24	1.73	17	206	0.69
And	1,131.00	1,171.00	40.00	0.52	0.06	3.03	14	625	0.56
And	1,183.00	1,231.00	48.00	0.52	0.07	3.13	14	437	0.55
And	1,259.00	1,300.00	41.00	0.60	0.07	5.48	83	1,021	0.67
ALD-26-264 - Total Depth - 400.40 m
No Reportable Intervals

ALD-26-267 - Total Depth – 1,393 m
Interval	135.70	1,393.00	1,257.30	0.62	0.05	1.94	66	240	0.66
Incl.	241.00	1,393.00	1,152.00	0.66	0.05	2.07	70	212	0.70
Incl.	514.00	1,027.00	513.00	1.01	0.08	3.58	64	248	1.06
Incl.	520.00	734.00	214.00	1.49	0.16	1.88	45	31	1.57
And	801.00	837.00	36.00	0.81	0.02	2.22	93	235	0.85
And	908.00	949.50	41.50	0.81	0.01	2.94	109	524	0.85
^{The grades are uncut. CuEq values were calculated using copper, gold, silver, and molybdenum. Metal prices utilized for the calculations are Cu = US$3.00/lb, Au = US$1,400/oz, Ag = US$18/oz, and Mo = US$10/lb. Recoveries used for the supporting metals found in the CuEq equation are as follows: Au = 50%, Ag = 51%, (based on historical metallurgical test work) and Mo = 70% (benchmarking from similar deposits). The formula utilized to calculate equivalent values is CuEq % = Cu % + (Au g/t * 0.34025) + (Ag g/t * 0.00446) + (Mo ppm * 0.00023). EXT indicates the hole was extended from a previously drilled hole. Intervals represent true thickness of the deposit.}

Project Update

Turnaround times at assay labs have been much longer than expected, which has led to delays in releasing drill results from the previous field campaign. It is expected all final assays should be received shortly. Due to the delay in receiving assays, the completion of the updated mineral resource estimate will be pushed out by one month to October 2026. This isn’t expected to delay the pre-feasibility timeline, with expected delivery in Q2/Q3 2027.

Qualified Person

The scientific and technical data contained in this news release has been reviewed and approved by Dr. Kevin B. Heather, B.Sc. (Hons), M.Sc, Ph.D, FAusIMM, FGS, Chief Geological Officer and director of Aldebaran, who serves as the qualified person (QP) under the definitions of National Instrument 43-101.

ON BEHALF OF THE ALDEBARAN BOARD

(signed) “John Black”

John Black, Chief Executive Officer and Director
Tel: +1 (604) 685-6800
Email: info@aldebaranresources.com

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Ben Cherrington
Manager, Investor Relations
Phone: +44 7538 244 208
Email: ben.cherrington@aldebaranresources.com

About Aldebaran Resources Inc.

Aldebaran is a mineral exploration company that was spun out of Regulus Resources Inc. in 2018 and has the same core management team. Aldebaran holds an 80% interest in the Altar copper-gold project in San Juan Province, Argentina. The Altar project hosts multiple porphyry copper-gold deposits with potential for additional discoveries. Altar forms part of a cluster of world-class porphyry copper deposits which includes Los Pelambres (Antofagasta Minerals), El Pachón (Glencore), and Los Azules (McEwen Copper). In November 2024 the Company announced an updated mineral resource estimate for Altar, prepared by Independent Mining Consultants Inc. and based on the drilling completed up to and including the 2023-24 field season (independent technical report prepared by Independent Mining Consultants Inc., Tucson, Arizona, titled "Technical Report, Estimated Mineral Resources, Altar Project, San Juan Province, Argentina", dated December 31, 2024 - see news release dated November 25, 2024). In October 2025 the Company announced a Preliminary Economic Assessment (PEA) for the Altar Project (independent technical report prepared by SRK Consulting Inc, Denver, Colorado, titled “NI 43-101 Technical Report Preliminary Economic Assessment Altar Project San Juan, Argentina”, dated September 30, 2025 – see news release dated October 30, 2025).

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

Sampling and Analytical Procedures

Altar follows systematic and rigorous sampling and analytical protocols which meet and exceed industry standards. These protocols are summarized below and are available on the Aldebaran website at www.aldebaranresources.com.
All drill holes are diamond core holes with PQ, HQ or NQ core diameters. Drill core is collected at the drill site where recovery and RQD (Rock Quality Designation) measurements are taken before the core is boxed and transported to the Altar camp facilities, a short distance away, where the whole core is photographed under more optimum lighting conditions and geological quick log is produced. The whole-core is then marked and sampled into geological defined, systematic 1- to 2-metre sample intervals, unless the geologist determines the presence of an important geological contact, which should not be crossed. The whole-core is then cut-in-half with a diamond saw blade, with half the sample retained in the core box for future reference and the other half placed into a pre-labelled plastic bag, sealed with a two plastic security zip ties, and labeled with a unique sample number. The bagged samples are then placed into larger plastic sacks, and those sacks are sealed with another plastic security zip tie and labelled for shipment. The sacks are then placed onto wooden pallets and wrapped in plastic shrink-wrap and stored in a secure area pending shipment to a certified ALS laboratory sample preparation facility located in Mendoza, Argentina, where the samples are dried, crushed, and pulverized. The resulting sample pulps are sent by batch to the ALS laboratory in Lima for geochemical assay analysis, including a 30g fire assay with an atomic absorption (AA) finish analysis for gold and a full multi-acid digestion (4-acid) with ICP-AES analysis for other elements. Samples with results that exceed maximum detection values for gold are re-analyzed by fire assay with a gravimetric finish and other elements of interest are re-analyzed using precise ore-grade ICP analytical techniques. Aldebaran independently inserts certified control standards (Super Certified Reference Materials (SCRM’s), coarse field blanks, and duplicates into the sample stream to monitor data quality. These control samples represent 10-12% of the total samples submitted and are inserted “blindly” to the laboratory in the sample sequence prior to departure from the Aldebaran facilities.

Forward-Looking Statements

Certain statements regarding Aldebaran, including management's assessment of future-plans and operations, may constitute forward-looking statements under applicable securities laws and necessarily involve known and unknown risks and uncertainties, most of which are beyond Aldebaran's control. Often, but not always, forward-looking statements or information can be identified by the use of words such as "plans", "expects" or "does not expect", "is expected", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates" or "does not anticipate" or "believes" or variations of such words and phrases or statements that certain actions, events or results "may", "could", "would", "might" or "will" be taken, occur or be achieved.

Specifically, and without limitation, all statements included in this press release that address activities, events or developments that Aldebaran expects or anticipates will or may occur in the future, including the proposed exploration and development of the Altar project described herein, and management's assessment of future plans and operations and statements with respect to the completion of the anticipated exploration and development programs, the mineral resource estimate and pre-feasibility study, may constitute forward-looking statements under applicable securities laws and necessarily involve known and unknown risks and uncertainties, most of which are beyond Aldebaran's control. These risks may cause actual financial and operating results, performance, levels of activity and achievements to differ materially from those expressed in, or implied by, such forward-looking statements. Although Aldebaran believes that the expectations represented in such forward-looking statements are reasonable, there can be no assurance that such expectations will prove to be correct. The forward-looking statements contained in this press release are made as of the date hereof and Aldebaran does not undertake any obligation to publicly update or revise any forward-looking statements or information, whether as a result of new information, future events or otherwise, unless so required by applicable securities law.

Location Map of Drill Holes Completed in the 2025/2026 Field Season