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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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.

Advanced Search Examples (click to copy):

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

27032 results found.

  1. GRB 261024D: Glowbug gamma-ray detection
  2. GRB 261026B: NuSTAR detection of prompt emission
  3. GRB 261024D: NuSTAR detection of prompt emission
  4. GRB 261024C: NuSTAR detection of prompt emission
  5. GRB 261026A: Ondrejov D50 optical limit
  6. GRB 261026A: ULL-ASTRO-MASTER optical detection with LCO 40-cm telescope at Haleakalā Observatory
  7. GRB 261026A: J-band observations by the SYSU 80cm infrared telescope
  8. GRB 261026A: SVOM/VT optical observations
  9. IPN triangulation of GRB 260730B
  10. GRB 261026C: Fermi GBM Final Real-time Localization
  11. GRB 261020A: Insight-HXMT/HE detection
  12. GRB 261026A: WINTER J-band observations
  13. GRB 261024D: AstroSat CZTI detection of a long burst
  14. GRB 261024C: AstroSat CZTI detection of a long burst
  15. GRB 261019A: GECAM-B observation
  16. GRB 261019A: SVOM/GRM observation
  17. GRB 261026A: SVOM/VT optical observation from VHF data
  18. GRB 261026A: KAIT optical observations
  19. GRB 261026B: Fermi GBM Final Real-time Localization
  20. GRB 261024A: NuSTAR detection of prompt emission
  21. GRB 261026A: SVOM detection of a burst
  22. GRB 261025B: Fermi GBM Final Real-time Localization
  23. EP261025a: J-band upper limit with WINTER
  24. EP261023a: J-band upper limit with WINTER
  25. EP261025a: Einstein Probe detection of a fast X-ray transient
  26. GRB 261025A: Fermi GBM Final Localization Correction
  27. EP261023a: J band upper limit by SYSU 80cm infrared telescope
  28. GRB 261024B: Fermi GBM Final Real-time Localization
  29. GRB 261024A: BALROG localization (Fermi Trigger 814551785 / GRB 261024683)
  30. GRB 261024A: Fermi GBM Final Real-time Localization
  31. EP261023a: Mondy optical upper limit
  32. EP261015a: VLA non-detection
  33. EP261023a: NOT optical counterpart candidate
  34. EP261023a: Einstein Probe detection of an X-ray transient
  35. GRB 261019A: Insight-HXMT/HE detection
  36. The EP-WXT trigger 01709321472 is likely a flaring star
  37. NuSTAR 261020, a 830s hard X-ray transient
  38. EP261015a: GSP multiband optical follow-up observations
  39. GRB 261017A: SVOM/GRM observation
  40. GRB 261021A: Fermi GBM Final Real-time Localization
  41. GRB 261020B: AstroSat CZTI detection of a short burst
  42. Fermi-LAT Gamma-ray Observations of IceCube-261020A
  43. EP261015a: AZT-20 Assy-Turgen optical observations
  44. GRB 261020A: Fermi GBM Observation
  45. GRB 261017A: SAO RAS optical upper limit
  46. GRB 260903A
  47. EP261015a: Follow-up with the 1.3m DFOT
  48. EP261015a: Terskol Zeiss-2000 optical upper limit
  49. EP261007b: Further EP-FXT follow-up observations
  50. GRB 261017A: COLIBRÍ optical upper limit
  51. IceCube-261020A - IceCube observation of a high-energy neutrino candidate track-like event
  52. GRB 261020A: MAXI GSC detection
  53. GRB 261020A: Fermi GBM Final Real-time Localization
  54. GRB 261019A: Fermi GBM Final Localization
  55. GRB 261017A: Possible Swift/UVOT Detection
  56. GRB 261017A: Luminance-band upper limit from a 28cm telescope in Chengde
  57. EP261015b: NOT Optical Observations
  58. GRB 261017A: J band upper limit by the SYSU 80cm infrared telescope
  59. EP261015c: refined analysis of the EP-FXT observation favors a stellar flare interpretation
  60. GRB 261017A : MITSuME Akeno optical upper limits
  61. GRB 261017A: Nanshan/NEXT optical upper limit
  62. GRB 261017A: Enhanced Swift-XRT position
  63. GRB 261017A: Fermi GBM Observation
  64. GRB261010A: Retraction of Keck/MOSFIRE near-IR source
  65. GRB 261017A: Swift detection of a burst
  66. GRB 261017A: Fermi GBM Final Real-time Localization
  67. EP261015a: Tentative fading of the candidate optical counterpart from the NOT
  68. EP261015b: Refined analysis of EP-FXT observations
  69. EP261015b: J-band upper limit by the SYSU 80cm infrared telescope
  70. EP261015a: refined analysis of EP-FXT observations
  71. EP261015c: J-band upper limit with WINTER
  72. EP261015a: J-band upper limit with WINTER
  73. GRB 261011A: 1.3m DFOT optical upper limit
  74. GRB 261010A: Pan-STARRS z-band imaging and upper limit
  75. EP261015a: SVOM/VT optical observation
  76. EP241111a and EP250125a: Upper limits from SVOM/GRM Observations
  77. GRB 261010A: VLA radio observations
  78. EP261015a: COLIBRÍ optical observations
  79. EP261015c: Einstein Probe detection of a fast X-ray transient
  80. EP261015b: Einstein Probe detection of an X-ray transient
  81. EP261015a: Einstein Probe detection of a fast X-ray transient
  82. EP261015a (WXT 11900947714): Possible optical counterpart from NOT and LCO
  83. The EP-WXT trigger 01709321333 is likely a flaring star
  84. GRB 261010A: ASKAP non-detection of a radio afterglow
  85. GRB 261010A: LBT tentative near-infrared detection
  86. GRB 261011A: SAO RAS and AbAO optical observations
  87. GRB 261010A: Glowbug gamma-ray detection
  88. GRB 261008A: SVOM/GRM observation
  89. GRB 261009A: GECAM-B detection of a burst
  90. EP261006a : MeerKAT radio observations.
  91. GRB 261013A: Fermi GBM Final Real-time Localization
  92. Fermi-LAT Gamma-ray Observations of IceCube-261012A
  93. GRID detection of GRB 261010A
  94. GRB 261011A: GECAM-B observation
  95. GRB 261011B: GECAM-B observation
  96. GRB 261010A: J-band upper limit by the SYSU 80cm infrared telescope
  97. IceCube-260919A: No transient candidates from the Zwicky Transient Facility
  98. GRB 261011A: Enhanced Swift-XRT position
  99. GRB 261010A: a Type I-L (merger-driven) GRB candidate
  100. GRB 261011A: 10.4m GTC spectroscopic redshift (z = 2.407)

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