Skip to main content
New! BOOM Notices and Schema v7.0.0. See news and announcements

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.

Advanced Search Examples (click to copy):

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

27325 results found.

  1. GRB 260515A: JinShan optical counterpart candidate
  2. GRB 260515A: SVOM detection of a burst
  3. GRB 260510C: Glowbug gamma-ray detection
  4. EP260514a: GROWTH-India Telescope optical upper limit
  5. GRB 260511B: GMG Optical Upper Limit
  6. EP260514a: Global MASTER-Net observations report
  7. EP260514a: Einstein Probe detection of a fast X-ray transient
  8. EP260512a: LCO optical upper limits
  9. GRB 260511B: Mephisto multi-band optical followup
  10. Fermi GRB 260514A: Global MASTER-Net observations report
  11. GRB 260512A: AstroSat CZTI detection
  12. EP260512a: EP-FXT follow-up observation
  13. EP260507a: Xinglong Schmidt optical counterpart detection
  14. EP260512a: Global MASTER-Net observations report
  15. Fermi GRB 260513A: Global MASTER-Net observations report
  16. Fermi GRB 260512A: Global MASTER-Net observations report
  17. GRB 260511B: further SAO RAS optical observations
  18. GRB 260509A: SVOM/VT optical observations
  19. The EP-WXT trigger 01709262036 is likely a flaring star
  20. EP260512a: COLIBRÍ optical upper limits
  21. EP260512a: Einstein Probe detection of an X-ray transient
  22. GRB 260511B: further J-band observations by the SYSU 80 cm infrared telescope
  23. GRB 260511B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  24. GRB 260512A: NuSTAR detection of prompt emission
  25. GRB 260509A: Infrared J and Hs observations with MDM/MIRAGE
  26. GRB 260510C: Infrared J and Hs detections with MDM/MIRAGE
  27. EP260507a: Infrared J and Hs upper limits with MDM/MIRAGE
  28. GRB 260511A: Glowbug gamma-ray detection
  29. GRB 260511B: SAO RAS optical observations
  30. GRB 260510D: Glowbug gamma-ray detection of a likely short burst
  31. GRB 260511B: FRAM-ORM optical detection
  32. GRB 260511A: EP-FXT follow-up observation
  33. GRB 260511B: EP-FXT follow-up observation
  34. GRB 260511B: LCO optical counterpart detection
  35. GRB260511B: MAO/AZT-22 optical observations
  36. GRB 260511B: LCO optical observations
  37. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) further optical observations
  38. GRB 260511B: SVOM/COLIBRÍ (FM-GFT) optical observations
  39. GRB 260510B: EP-FXT follow-up observation
  40. GRB 260510C: Fermi GBM Observation
  41. GRB 260509A: SAO RAS optical observations
  42. GRB 260511A: REM near-infrared detection
  43. GRB 260511B: GROWTH-India Telescope optical observations
  44. GRB 260506B: Glowbug gamma-ray detection
  45. GRB 260506A: Glowbug gamma-ray detection of a short burst
  46. GRB 260511B: J-band observations by the SYSU 80 cm infrared telescope
  47. GRB 260511B: NuSTAR detection of prompt emission
  48. GRB 260511A: NuSTAR detection of prompt emission
  49. GRB 260511B: Fermi GBM Detection
  50. GRB 260511B: SVOM/VT optical observation with VHF data
  51. GRB 260511B: TRT optical observation
  52. GRB 260511B : MITSuME Akeno optical afterglow candidate detection
  53. GRB 260511A: Fermi GBM Detection
  54. GRB 260511B SVOM/C-GFT optical counterpart detection
  55. EP260509a: LCO optical upper limits
  56. GRB 260511A: UTGO H50 optical afterglow observation
  57. GRB 260511B: SVOM detection of a burst
  58. GRB 260510C: EP-FXT follow-up observation
  59. EP260509a: EP-FXT non-detection and upper limit
  60. GRB 260511A: SVOM/VT optical observation with VHF data
  61. Fermi GRB 260511A: Global MASTER-Net observations report
  62. GRB 260511A: KAIT optical afterglow observations
  63. GRB 260511A: LCO optical afterglow detection
  64. GRB 260511A: SVOM/COLIBRÍ (FM-GFT) optical counterpart
  65. GRB 260511A: TRT optical counterpart detection
  66. GRB 260511A: SVOM detection of a bright burst
  67. GRB 260511A: BALROG localization (Fermi Trigger 800172815 / GRB 260511259)
  68. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  69. GRB 260510C: MAXI/GSC detection
  70. EP260509a: Global MASTER-Net observations report
  71. Fermi GBM Sub-Threshold Detection of GRB 260510B
  72. GRB 260510C: SVOM detection of a burst
  73. GRB 260510B: LCO optical upper limits
  74. EP260509a: Einstein Probe detection of an X-ray transient
  75. GRB 260509A: Liverpool Telescope optical observations
  76. GRB 260510B: SVOM detection of a burst
  77. GRB 260509A: LCO optical observations
  78. SVOM GRB 260509A: MASTER-OAFA optical observation
  79. Fermi GRB 260510A: Global MASTER-Net observations report
  80. GRB 260509A: KAIT optical observations
  81. GRB 260509A: SVOM/COLIBRÍ (FM-GFT) observations
  82. GRB 260509A: SVOM/VT optical candidate with VHF data
  83. GRB 260509A: LCO optical counterpart detection
  84. GRB 260509A: SVOM detection of a burst
  85. IceCube-260504A: Upper limits from a search for additional neutrino events in IceCube
  86. EP260507a: REM optical/NIR observations
  87. EP260507a: refined analysis of the EP-WXT and EP-FXT observations
  88. GRB 260507B / EP260507a: Fermi-GBM Sub-Threshold Detection
  89. EP260507a: COLIBRÍ optical observations
  90. EP260507a: NOT optical observations
  91. EP260507a: further Liverpool Telescope observations
  92. EP260507a: Liverpool Telescope optical upper limits
  93. EP260507a: TRT optical counterpart detection
  94. EP260507a: Kinder optical counterpart candidate
  95. EP260507a: LCO optical counterpart
  96. EP260507a: Einstein Probe detection of an X-ray transient
  97. GRB 260506B: BALROG localization (Fermi Trigger 799765648 / GRB 260506547)
  98. Fermi GRB 260506A: Global MASTER-Net observations report
  99. IceCube Alert 260505A: Global MASTER-Net observations report
  100. GRB 260430B: Glowbug gamma-ray detection

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov