Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. 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"

32763 results found.

  1. GRB 240713A: JinShan optical upper limits
  2. GRB 240713A: OHP/T120 optical upper limit
  3. GRB240713A: X-ray follow-up observation with EP-FXT (duplicate submission of GCN 36859)
  4. GRB240713A: X-ray follow-up observation with EP-FXT
  5. GRB240713A: Optical upper limit with Kinder observations
  6. Fermi Sub-threshold Observation of GRB240713A
  7. EP240708a: GSP optical upper limit
  8. LIGO/Virgo/KAGRA S240627by: Updated Sky localization and EM Bright Classification
  9. EP240708a: KAIT optical upper limit
  10. Fermi GRB 240710A: Global MASTER-Net observations report
  11. EP240708a: NOT optical observations
  12. EP240708a: SVOM/C-GFT optical upper limit
  13. EP240708a: X-ray follow-up observations with EP/FXT and Swift/XRT
  14. EP240708a: Optical upper limits with Kinder observations
  15. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  16. EP240703b: GSP optical upper limit
  17. EP240703b: TRT optical upper limits
  18. EP240703a: TRT further optical observation
  19. EP240702a: TRT optical upper limits
  20. Konus-Wind detection of GRB 240627A
  21. LIGO/Virgo/KAGRA S240705at: Updated Sky localization
  22. EP240703a and EP240703b: Swift/XRT upper limits
  23. LIGO/Virgo/KAGRA S240705at: Identification of a GW compact binary merger candidate
  24. EP240703a: KAIT optical upper limit
  25. EP240703a: BTA observations
  26. EP240703c: Kinder optical follow-up and Swift XRT observations
  27. EP240703a: Liverpool Telescope optical follow-up observations
  28. EP240703a/GRB 240703A: TRT optical candidate likely not real
  29. EP240703a: Kinder optical follow-up observations
  30. LIGO/Virgo/KAGRA S240703ad: Updated Sky localization
  31. LIGO/Virgo/KAGRA S240703ad: Identification of a GW compact binary merger candidate
  32. EP240703a/GRB 240703A: TRT and JinShan decaying optical afterglow candidate
  33. IPN triangulation of GRB 240627A
  34. GRB 240619A: Host galaxy redshift from VLT/X-shooter
  35. LIGO/Virgo/KAGRA S240422ed: Updated significance estimate
  36. The first three GRBs detected by SVOM: X-ray Upper Limits from EP-WXT
  37. Konus-Wind detection of GRB 240703A (a counterpart of EP240703a)
  38. EP240702a: Swift/XRT upper limit
  39. EP240702a: GSP optical upper limit
  40. Fermi GRB 240702A: Global MASTER-Net observations report
  41. GRB 240627A: CALET Gamma-Ray Burst Monitor detection
  42. LIGO/Virgo/KAGRA S240630t: Updated Sky localization
  43. LIGO/Virgo/KAGRA S240629by: Updated Sky localization
  44. LIGO/Virgo/KAGRA S240630t: Identification of a GW compact binary merger candidate
  45. LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
  46. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
  47. Fermi GRB 240629A: Global MASTER-Net observations report
  48. Fermi Gamma-ray Burst Monitor trigger 741288821/240628732 is not a GRB
  49. LIGO/Virgo/KAGRA S240629by: Identification of a GW compact binary merger candidate
  50. IPN triangulation of GRB 240619C
  51. GRB 240627A: NuSTAR Detection of the long GRB
  52. GRB 240615A: SAI CMO J- band observations
  53. EP240626a: Montarrenti Observatory optical upper limit
  54. LIGO/Virgo/KAGRA S240627by: Identification of a GW compact binary merger candidate
  55. EP240625a: GRANDMA Optical Upper Limits
  56. EP240626a: EP-FXT detection of the X-ray emission
  57. GRB 240624A: Swift-BAT refined analysis
  58. Konus-Wind detection of GRB 240619A
  59. Fermi GRB 240625B: Global MASTER-Net observations report
  60. GRB 240624B: CALET Gamma-Ray Burst Monitor detection
  61. GRB 240625A: Fermi GBM Observation
  62. EP240625a: NOT optical counterpart candidate
  63. EP240625a: EP-FXT detection of the X-ray emission
  64. GRB 240624B: GRBAlpha detection
  65. GRB240624A: Fermi GBM Observation
  66. Swift GRB 240624A: Global MASTER-Net observations report
  67. GRB240615A: Gemini-North observations of the BAT and XRT positions
  68. Fermi GRB 240624A: Global MASTER-Net observations report
  69. GRB240615A: Gemini-North observations of the BAT and XRT positions
  70. GRB 240619A: detection of a radio counterpart with AMI-LA
  71. EP240618a: NOT further optical observations
  72. GRB 240619A: J-band detection with WINTER (duplicate submission of GCN 36739)
  73. GRB 240619A: J-band detection with WINTER
  74. LIGO/Virgo/KAGRA S240622h: Updated Sky localization and Source Classification
  75. EP240618a: NOT optical counterpart candidate
  76. LIGO/Virgo/KAGRA S240621em: Updated Sky localization and Source Classification
  77. GRB 240529A: JinShan optical observations
  78. LIGO/Virgo/KAGRA S240621dy: Updated Sky localization and Source Classification
  79. LIGO/Virgo/KAGRA S240621eb: Updated Sky localization and Source Classification
  80. EP240618a: GSP optical upper limit
  81. LIGO/Virgo/KAGRA S240622h: Identification of a GW compact binary merger candidate
  82. LIGO/Virgo/KAGRA S240621em: Identification of a GW compact binary merger candidate
  83. LIGO/Virgo/KAGRA S240621eb: Identification of a GW compact binary merger candidate
  84. LIGO/Virgo/KAGRA S240621dy: Identification of a GW compact binary merger candidate
  85. IPN triangulation of GRB 240615A (short)
  86. X-ray transient EP240618a: Fermi/GBM non-detection
  87. GRB 240619A: GRBAlpha detection
  88. EP240618a: Swift/XRT upper limit
  89. EP240617a: tentative Swift/XRT detection of the afterglow
  90. GRB 240619A: Swift-XRT probable afterglow detection
  91. GRB 240619A: Swift ToO observations
  92. GRB 240619A: CALET Gamma-Ray Burst Monitor detection
  93. GRB 240619C: NuSTAR automated detection of the GRB
  94. GRB 240619A: Fermi GBM Observation
  95. Fermi GBM Sub-Threshold Detection of GRB 240619C
  96. GRB 240619A: GOTO candidate optical afterglow
  97. EP240618a: Abastumani optical observationsEP240618a
  98. GRB 240615A: NOT optical observations
  99. EP240618a: GRANDMA Optical Upper Limits
  100. EP240618a: TRT optical upper limit

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