Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

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"

28201 results found.

  1. GRB 241029A: GRBAlpha detection
  2. EP241101a: BOOTES-7 optical upper limit
  3. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  4. EP241101a: EP-WXT detection of a fast X-ray transient
  5. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  6. EP241021a: Upper limit from Konus-Wind observations
  7. EP241021a: Liverpool Telescope optical follow-up observations
  8. GRB 241030B: Swift-XRT refined Analysis
  9. EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow
  10. GRB 241101A: Swift detection of a burst
  11. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  12. GRB 241030B: Montarrenti Observatory optical upper limit
  13. EP241026b: Liverpool Telescope optical follow-up
  14. EP241021a: AMI-LA radio detection
  15. GRB 241030B: LCOGT Optical Upper Limits
  16. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  17. GRB 241030B: Swift/UVOT Detection
  18. GRB 241029A: LCO optical detection
  19. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  20. GRB 241030B: SVOM/GRM observation
  21. GRB 241030B : MITSuME Akeno optical upper limits
  22. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  23. GRB 241030B: SVOM/VT optical afterglow observations
  24. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  25. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  26. GRB 241030B: BTA observations
  27. GRB 241029A: SVOM/VT optical afterglow observations
  28. GRB 241030A: detection of the bright optical counterpart in ATLAS forced photometry
  29. GRB 241030B: Enhanced Swift-XRT position
  30. GRB 241030B: optical observations from the INAF Asiago Observatory
  31. EP241021a: Swift-UVOT detection
  32. GRB241030B: GRANDMA/TAROT Upper Limit
  33. GRB 241030A: Swift-XRT refined Analysis
  34. GRB 241030B: AKO Optical Afterglow Detection
  35. GRB 241030B: Nanshan/HMT optical afterglow detection
  36. GRB 241030B: SVOM/ECLAIRs detection of a burst
  37. GRB 241030B: Prompt enhanced Swift-XRT position
  38. Konus-Wind detection of GRB 241030A
  39. GRB 241030B: Swift detection of a burst
  40. GRB 241030B: Fermi GBM Final Real-time Localization
  41. GRB 241030A: Fermi-LAT detection
  42. GRB 240912A: radio detection with the VLA
  43. GRB 241030A: AKO Optical Afterglow Detection
  44. GRB 241030A: Swift/UVOT Detection
  45. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  46. GRB 241026A: LBT optical observations
  47. EP241026b: EP-FXT follow-up observation
  48. GRB 241030A: Multiband optical detection with Mephisto
  49. GRB 241030A: SVOM/VT optical afterglow observations
  50. GRB 241025A: The discovery of a BdHN I from data of Swift, Fermi, SVOM and Einstein Probe telescopes
  51. GRB 241030A : MITSuME Akeno optical afterglow detection
  52. GRB 241030A: Enhanced Swift-XRT position
  53. GRB 241029A: GROWTH-India Telescope optical follow up
  54. GRB 241030A: TRT optical observations
  55. GRB 241030A: Keck/LRIS spectroscopic redshift z = 1.411
  56. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  57. GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
  58. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  59. GRB 241030A: Fermi GBM Final Real-time Localization
  60. EP240919a / GRB 240919A: ATCA Detection of Radio Counterpart
  61. GRB 241029A: GTC/OSIRIS+ spectroscopic redshift z=1.072
  62. GRB 241026A: Swift/UVOT Upper Limits
  63. GRB 241029A: Swift-XRT observations
  64. GRB 241029A: AKO Optical Afterglow Detection
  65. GRB 241029A: GOTO optical afterglow detection
  66. GRB 241029A: MASTER early optical counterpart detection
  67. GRB 241029A: Xinglong-2.16m optical afterglow confirmation
  68. GRB 241029A: TRT optical afterglow candidate detection
  69. GRB 241029A: Swift ToO observations
  70. GRB 241029A : Detection and localization of a bright long GRB by SVOM/ECLAIRs
  71. GRB 241029A: Fermi GBM Final Real-time Localization
  72. GRB 240821A: Keck/LRIS spectroscopic observations
  73. EP241021a: Gemini-South detection of optical rebrightening
  74. GRB 241026A: the 100th GRB detected by GRBAlpha
  75. GRB 241026A: TNOT optical counterpart detection
  76. Konus-Wind detection of GRB 241025A
  77. GRB 241025A (EP241025a): Optical afterglow observations with the Tsinghua-Nanshan Optical Telescope
  78. GRB 241026A: GECAM detection
  79. GRB 241025A: Swift/UVOT Detection
  80. GRB 241026A: GROWTH-India Telescope optical observations
  81. GRB 241026A: BTA redshift identification of z = 2.79
  82. GRB 241026A: J-band observations with WINTER
  83. GRB 241026A: Las Cumbres optical detection
  84. GRB 241025A: Mondy optical observations
  85. EP241026a (GRB 241026A): EP on-board trigger and follow-up observation
  86. GRB 241026A: Swift-XRT refined Analysis
  87. GRB 241026A: Enhanced Swift-XRT position
  88. GRB 241026A: KAIT optical observations
  89. EP241026b: EP detection of a fast X-ray transient
  90. GRB 241026A: COLIBRÍ Detection of the Optical Counterpart
  91. GRB 241026A: SAO RAS observations of possible optical afterglow
  92. GRB 241026A: Prompt enhanced Swift-XRT position
  93. GRB 241026A: Swift detection of a burst
  94. GRB 241026A: Fermi GBM Final Real-time Localization
  95. GRB241025A: 1.3m DFOT optical afterglow detection
  96. EP241021a: optical follow-up observations with Xinglong Observatory
  97. ​GRB 241025A: optical photometry from Konkoly
  98. GRB 241025A: GROWTH-India Telescope optical observations
  99. GRB 241025A: COLIBRÍ Detection of the Afterglow
  100. GRB 241025A: Swift-XRT refined Analysis

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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