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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

20816 results found.

  1. EP241107a: AKO Optical Afterglow Detection
  2. GRB 241025A: LBT optical observations
  3. GRB 241105A: VLT/FORS2 optical afterglow rapid fading
  4. GRB 241105A: Swift/UVOT Detection
  5. EP241101a: CrAO ZTSH optical observations
  6. GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  7. LIGO/Virgo/KAGRA S241106ba: 1 counterpart neutrino candidate event from an IceCube neutrino search
  8. LIGO/Virgo/KAGRA S241102o: 1 counterpart neutrino candidate event from an IceCube neutrino search
  9. GRB 241105A: Swift-XRT afterglow detection
  10. GRB 241104A: Swift-XRT observations
  11. GRB 240511A: LCO upper limits
  12. GRB 241104A: Fermi GBM Observation
  13. GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
  14. GRB 241104A: NOT optical non-detection
  15. GRB 241104A: SVOM/VT optical candidate
  16. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  17. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  18. EP241104a: EP detection of GRB 241104A X-ray emission
  19. GRB 241010A: host galaxy redshift z = 0.977
  20. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  21. GRB 240821A: further radio observations with the VLA
  22. EP241101a: EP-FXT observations update
  23. EP241103a: GIT optical upper limit
  24. EP241021a: OHP/T193 further optical observations
  25. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  26. EP241103a: GOTO optical upper limit
  27. EP241103a: Swift XRT detection and improved X-ray position
  28. EP241021a: continued SOAR observations
  29. EP241101a: Optical upper limits with Kinder observations
  30. EP241101a: OHP/T193 optical observations
  31. EP241103a: Gemini optical limits
  32. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  33. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  34. EP241103A: LCO optical observations
  35. EP241103a: an X-ray transient detected by Einstein Probe
  36. GRB 241030A: Rapid release of TESS data.
  37. S241102cy: Identification of a GW compact binary merger candidate
  38. LIGO/Virgo/KAGRA S241102br: NED Galaxies in the Localization Volume
  39. LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate
  40. Kinder optical follow-up observations of EP241021a, EP241026b, and EP241030a/GRB241030A
  41. GRB241030A: OHP/T193 optical observations
  42. GRB 241101A: FRAM-ORM optical limit
  43. LIGO/Virgo/KAGRA S241101ee: Identification of a GW compact binary merger candidate
  44. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  45. GRB 241030A: further SAO RAS optical observations
  46. GRB 241030A: Optical Observations via Virtual Telescope Project
  47. EP241021a: Liverpool Telescope optical follow-up observations
  48. GRB 241026A: SAO RAS optical observations
  49. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  50. GRB 241101A: Swift detection of a burst
  51. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  52. EP241021a: OHP/T193 optical observations
  53. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  54. GRB 241030B: Montarrenti Observatory optical upper limit
  55. EP241026b: Liverpool Telescope optical follow-up
  56. GRB 241030A: SAO RAS optical observations
  57. EP241021a: AMI-LA radio detection
  58. GRB 241030B : GIT optical upper limits
  59. GRB 241030B: LCOGT Optical Upper Limits
  60. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  61. GRB 241030B: Swift/UVOT Detection
  62. GRB 241029A: LCO optical detection
  63. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  64. GRB 241030B : MITSuME Akeno optical upper limits
  65. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  66. GRB 241030B: SVOM/VT optical afterglow observations
  67. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  68. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  69. GRB 241030B: BTA observations
  70. GRB 241029A: SVOM/VT optical afterglow observations
  71. GRB 241030B: Enhanced Swift-XRT position
  72. GRB 241030B: optical observations from the INAF Asiago Observatory
  73. GRB241030B: GRANDMA/TAROT Upper Limit
  74. GRB 241030B: SAO RAS optical observations
  75. GRB 241030B: AKO Optical Afterglow Detection
  76. GRB 241030B: Nanshan/HMT optical afterglow detection
  77. GRB 241030B: Swift detection of a burst
  78. GRB 240912A: radio detection with the VLA
  79. GRB 241030A: AKO Optical Afterglow Detection
  80. GRB 241030A: Swift/UVOT Detection
  81. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  82. GRB 241030A: SVOM/C-GFT optical observations
  83. GRB 241026A: LBT optical observations
  84. EP241021a: Optical rebrightening observations with Mephisto
  85. GRB 241030A: Multiband optical detection with Mephisto
  86. GRB 241030A: SVOM/VT optical afterglow observations
  87. GRB 241030A : MITSuME Akeno optical afterglow detection
  88. GRB 241030A: Enhanced Swift-XRT position
  89. GRB 241029A: GROWTH-India Telescope optical follow up
  90. GRB 241030A: Keck/LRIS spectroscopic redshift z = 1.411
  91. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  92. GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
  93. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  94. GRB 241029A: SAO RAS optical observations
  95. GRB 241026A: SAO RAS optical observations
  96. EP241021a: SAO RAS observations of rebrightening
  97. GRB 241029A: GTC/OSIRIS+ spectroscopic redshift z=1.072
  98. MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
  99. GRB 241026A: Swift/UVOT Upper Limits
  100. GRB 241029A: AKO Optical Afterglow Detection

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