| Clas. | Ref. CAT | PI | Awarded time | Instrument | Program |
|---|
| B | 155-GTC122/21A | Nancy Elias Rosa | G (13hrs) | Osiris | Peeking into the Very Center of Stellar Explosions with GTC Nebular Spectroscopy |
| B | 158-GTC127/21A | Ignacio Ferreras | A (3.1hrs) | HORuS | A high (spectral) resolution view of quiescent galaxies |
| B | 141-GTC105-A/21A | Javier Licandro Goldaracena | 4 A (1hrs) | Osiris | Characterizing new discovered faint Main Belt Comets |
| B | 141-GTC106-B/21A | Javier Licandro Goldaracena | 2 A (1hrs) | Osiris | Characterizing new discovered faint Main Belt Comets |
| B | 175-GTC144-A/21A | Hannu Parviainen | D (3.6hrs) | Osiris | Validation of a transiting exoplanet candidate TOI 2283.01 using multicolour transit photometry |
| B | 175-GTC145-B/21A | Hannu Parviainen | D (3.6hrs) | Osiris | Validation of a transiting exoplanet candidate TOI 2283.01 using multicolour transit photometry |
| B | 148-GTC113/21A | Marta Lorenzo González | D (5hrs) | Osiris | Sextans-B: A new environment to study the mass-loss of very metal-poor massive stars |
| B | 156-GTC123-A/21A | Nancy Elias Rosa | 3 A (0.67hrs) | Osiris | Looking at the Gap Transients from a new perspective. |
| B | 156-GTC124-B/21A | Nancy Elias Rosa | G (16hrs) | Osiris | Looking at the Gap Transients from a new perspective. |
| B | 176-GTC146/21A | Roi Alonso Sobrino | G (3.65hrs) | Osiris | Measuring the physical parameters of a white dwarf with a low mass irradiated companion |
| B | 164-GTC133/21A | Eduardo Martin Guerrero de Escalante | D (6hrs) | Osiris | Spectroscopic characterization of isolated planetary mass objects across time |
| B | 145-GTC110/21A | Borja Montoro Molina | G (3hrs) | Osiris | OSIRIS investigation of the planetary nebula that turned off its central star |
| B | 150-GTC115-A/21A | Javier Román García | D (16.1hrs) | Osiris | Probing the relic nature of the UGC 7321 superthin galaxy |
| B | 150-GTC116-B/21A | Javier Román García | D (2.1hrs) | Osiris | Probing the relic nature of the UGC 7321 superthin galaxy |
| B | 157-GTC126-B/21A | Jonay I. González Hernández | G (14.2hrs) | Osiris | Searching for the most-iron poor stars of the Milky Way |
| B | 161-GTC130/21A | David Jones | 4 G (1.75hrs) | Osiris | Spectroscopic target of opportunity follow-up of newly-discovered luminous red novae |
| B | 166-GTC135/21A | Josefa Becerra González | D (9.5hrs) | Osiris | Characterization of extreme gamma-ray emitters |
| B | 170-GTC139/21A | Helmut Dannerbauer | D (30hrs) | Osiris | Optical confirmation of the richest overdensity beyond z=5 |
| B | 136-GTC100/21A | Rafael Luque | A (4.7hrs) | Osiris | Probing the atmosphere of WASP-74b |
| B | 172-GTC141/21A | Raúl de la Fuente Marcos | D (1.5hrs) | Osiris | Follow-up observations of the farthest Solar System body ever observed at 132 AU from the Sun, with GTC/OSIRIS |
| B | 167-GTC136/21A | Miriam García García | D (20hrs) | Osiris | Physics and Evolution of Massive Stars at the very early Universe. |
| B | 169-GTC138/21A | Artemio Herrero Davó | A (5.2hrs) | HORuS | The nature of the obscured blue hypergiant J20395358+4222505 |
| B | 174-GTC143/21A | Ricardo Manuel Pérez Martínez | G (41hrs) | Osiris | Characterization of Extended ionized gas regions (EIGs) in galaxy clusters |
| C | 139-GTC103/21A | Alberto Rebassa Mansergas | D (20hrs) | Osiris | Follow-up spectroscopy of extremely-low mass white dwarfs identified in Gaia DR2 |
| C | 143-GTC108/21A | Jorge Sanchez Almeida | G (23hrs) | Osiris | Bona-Fide galaxies with metallicity inhomogeneities due to accretion-triggered star formation |
| C | 146-GTC111/21A | Carlos López San Juan | D (3.8hrs) | Osiris | Metal abundances of new polluted white dwarfs discovered with J-PLUS |
| C | 144-GTC109/21A | Raúl de la Fuente Marcos | G (6hrs) | Osiris | Investigating interstellar comet candidates with GTC/OSIRIS: C/2021 A9 (PANSTARRS) and C/2021 C1 (Rankin) |
| C | 153-GTC119-A/21A | Manuel Ángel Pérez Torres | D (5.2hrs) | Osiris | Understanding fast X-ray transients |
| C | 153-GTC120-B/21A | Manuel Ángel Pérez Torres | G (2hrs) | Osiris | Understanding fast X-ray transients |
| C | 165-GTC134/21A | Enrique Perez Jimenez | D (10.75hrs) | Osiris | Kinematics of time-delay lenses in the North |