Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

3613 results found.

  1. GRB 241127A: Swift-BAT refined analysis
  2. GRB 241026A: radio detection with the VLA
  3. GRB241120A: OHP/T193 optical observations
  4. GRB 241120A: Mondy and AbAO optical observations
  5. Fermi GRB 241118A: Global MASTER-Net observations report
  6. LIGO/Virgo/KAGRA S241114bi: Coverage and upper limits from MAXI/GSC observations
  7. EP241113a: Global MASTER-Net observations report
  8. Fermi trigger No 753166198: Global MASTER-Net observations report
  9. Fermi-GBM Sub-Threshold Detection of GRB 241112B
  10. GRB 241112B: SVOM/GRM observation
  11. GRB 241112B : detection of a long GRB by SVOM/ECLAIRs
  12. Fermi trigger No 752990530: Global MASTER-Net observations report
  13. Fermi trigger No 752878030: Global MASTER-Net observations report
  14. LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations
  15. EP241107a: AKO Optical Afterglow Follow-Up Observations
  16. GRB 240511A: LCO upper limits
  17. Fermi GRB 241105A: Global MASTER-Net observations report
  18. Fermi GRB 241104A: Global MASTER-Net observations report
  19. EP241101a: EP-FXT observations update
  20. Fermi trigger No 752365806: Global MASTER-Net observations report
  21. EP241103a: Swift XRT detection and improved X-ray position
  22. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  23. GRB 241101A: Swift detection of a burst
  24. Fermi trigger No 752083996: Global MASTER-Net observations report
  25. EP EP241030a: Global MASTER-Net observations report
  26. Fermi trigger No 752006065: Global MASTER-Net observations report
  27. GRB 241030B: Swift detection of a burst
  28. GRB 240912A: radio detection with the VLA
  29. Fermi GRB 241030A: Global MASTER-Net observations report
  30. GRB 241026A: SAO RAS observations of possible optical afterglow
  31. Fermi GRB 241026A: Global MASTER-Net observations report
  32. GRB 241026A: Prompt enhanced Swift-XRT position
  33. EP241021a: optical follow-up observations with Xinglong Observatory
  34. Fermi GRB 241025A: Global MASTER-Net observations report
  35. IPN triangulation of GRB 241021A (long)
  36. GRB241017A: 1.3m DFOT optical upper limit
  37. Fermi trigger No 750788395: Global MASTER-Net observations report
  38. GRB 241017A : Detection of a weak and soft long duration GRB by SVOM/ECLAIRs
  39. Fermi GRB 241016A: Global MASTER-Net observations report
  40. GRB 240916A: radio detection with the VLA
  41. GRB241013A: REM observations
  42. Fermi trigger No 750211959: Global MASTER-Net observations report
  43. IceCube Alert 241006.94: Global MASTER-Net observations report
  44. EP EP240930a: Global MASTER-Net observations report
  45. Fermi GRB 240929A: Global MASTER-Net observations report
  46. LIGO/Virgo S240919bn: GOTO optical upper limits
  47. GRB 240918B: AstroSat CZTI detection
  48. EP240919a: EP-FXT follow-up observation update
  49. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  50. GRB 240918B: Fermi GBM Detection
  51. GRB 240912A: Swift-BAT refined analysis
  52. LIGO/Virgo/KAGRA S240915b: Coverage and upper limits from MAXI/GSC observations
  53. LIGO/Virgo/KAGRA S240910ci: Coverage and upper limits from MAXI/GSC observations
  54. Fermi GRB 240908A: Global MASTER-Net observations report
  55. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  56. GRB 240902B: AstroSat CZTI detection of a long burst
  57. GRB 240825A: Montarrenti Observatory optical follow-up observations
  58. Fermi trigger No 746923430: Global MASTER-Net observations report
  59. LIGO/Virgo/KAGRA S240830gn: Coverage and upper limits from MAXI/GSC observations
  60. Fermi trigger No 746587425: Global MASTER-Net observations report
  61. Swift GRB240829.16: Global MASTER-Net observations report
  62. Fermi trigger No 746438824: Global MASTER-Net observations report
  63. GRB 240824A: GIT optical upper limit
  64. GRB 240824B: Ondrejov D50 optical limit
  65. GRB 240825A: AKO Optical Follow-Up Observations
  66. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  67. GRB 240824B: Fermi GBM Observation
  68. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  69. GRB 240824B: Swift-XRT afterglow detection
  70. GRB 240824B: Swift/BAT arcminute localization of a burst
  71. GRB 240824B: MAXI/GSC detection
  72. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  73. Fermi GRB 240821B: Global MASTER-Net observations report
  74. Fermi trigger No 745866488: Global MASTER-Net observations report
  75. Trigger 1249878: Swift detection of another burst from SGR 1E 1841-045 / Kes 73
  76. EP240816a: EP detection of a fast X-ray transient and follow-up observation
  77. Fermi GRB 240814B: Global MASTER-Net observations report
  78. GRB 240808A: AstroSat CZTI detection
  79. GRB 240809B: MAXI/GSC detection
  80. GRB 240808A: SVOM/GRM observation
  81. EP EP240807a: Global MASTER-Net observations report
  82. EP EP240806a: Global MASTER-Net observations report
  83. GRB 240805B: Swift-BAT refined analysis
  84. Fermi trigger No 744629911: Global MASTER-Net observations report
  85. Fermi GRB 240805A: Global MASTER-Net observations report
  86. Fermi GRB 240804A: Global MASTER-Net observations report
  87. Fermi trigger No 744459130: Global MASTER-Net observations report
  88. Fermi trigger No 744128417: Global MASTER-Net observations report
  89. GRB240730A: BOOTES-5/JGT early optical upper limit
  90. GRB 240720A: Swift-BAT refined analysis
  91. Fermi trigger No 743219692: Global MASTER-Net observations report
  92. GRB 240721A: Fermi GBM Final Real-time Localization
  93. Fermi GRB 240720A: Global MASTER-Net observations report
  94. Fermi-LAT gamma-ray observations of IceCube-cascade-240714A
  95. LIGO/Virgo/KAGRA S240711cm: Coverage and upper limits from MAXI/GSC observations
  96. Fermi trigger No 742405878: Global MASTER-Net observations report
  97. Fermi trigger No 742317942: Global MASTER-Net observations report
  98. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  99. Fermi trigger No 741448122: Global MASTER-Net observations report
  100. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations

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