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"

27549 results found.

  1. GRB 090126A: Swift-XRT afterglow confirmation
  2. GRB 090202: Fermi GBM detection
  3. GRB 090131: Fermi GBM detection
  4. GRB 090201: Swift-XRT refined analysis
  5. GRB090201: Swift UVOT upper limits
  6. GRB 090201: object inside the enhanced XRT error circle
  7. GRB 090201: Enhanced Swift-XRT position
  8. GRB 090201: VLT NIR observations
  9. GRB 090201: VLT afterglow candidate
  10. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  11. GRB 090201: ROTSE-III Optical Limits
  12. GRB 090201: Swift detection of a burst
  13. GRB 090126A: Swift/UVOT Upper Limits
  14. GRB 090129: Swift detection of a burst
  15. GRB 090102: HST observations and host galaxy
  16. GRB 090126C: Fermi GBM detection
  17. GRB 090126A: Swift-XRT Refined Analysis
  18. GRB 090126B: Fermi GBM detection
  19. Konus-Wind detection of very bright SGR-like burst on January 25, 2009
  20. GRB 090118: no afterglow candidate
  21. GRB 090123: GROND detection
  22. 1E1547.0-5408: Swift detection of dust halo
  23. GRB 090123: Swift XRT refined analysis
  24. GRB 090123: Swift/UVOT Observations
  25. GRB090123: Enhanced Swift-XRT position
  26. GRB 090123: Swift detection of a burst
  27. GRB 090118: Swift XRT Observations - Confirmation of an Afterglow
  28. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  29. Trigger 340734: Swift detection of a possible short burst
  30. AXP 1E1547.0-5408 activity with SGR bursts
  31. GRB 090118: Subaru NIR Observation
  32. GRB 090118: KPNO 4m 2nd Epoch Observations
  33. GRB 090118 (BATSS): GRT Optical Observation
  34. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  35. GRB 090118: Swift-XRT observations
  36. GRB 090118: Possible burst detection from Swift-BAT slew data
  37. GRB 090117B : Fermi GBM detection
  38. GRB 090117: confirmation of the X-ray afterglow
  39. GRB 090117C - Fermi GRB Detection
  40. GRB 090117: GROND Upper Limits
  41. GRB090117 Swift/UVOT upper limits
  42. GRB090117: Swift-XRT detection of a possible candidate afterglow
  43. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  44. GRB 090113: Swift UVOT upper limits
  45. GRB 090113: GROND Upper Limits
  46. GRB 090113: Swift-XRT refined analysis
  47. GRB 090113: Observations from NOT
  48. GRB 090113: Enhanced Swift-XRT position
  49. GRB090113: XRT position
  50. GRB 090112B: Fermi GBM Detection
  51. GRB 090113: Swift detection of a burst
  52. GRB 090112: Fermi GBM detection
  53. GRB 090109: Fermi GBM detection
  54. GRB 090108B: Fermi GBM detection
  55. GRB 090111: Swift UVOT Upper Limits
  56. GRB 090108: Fermi GBM Detection
  57. GRB 090111: Swift-XRT refined analysis
  58. GRB 090111: Enhanced Swift-XRT position
  59. GRB 090111: Swift detection of a burst
  60. GRB090107B: Fermi GBM Detection
  61. GRB 090102: WSRT Radio Observations
  62. GRB 090107B: Swift XRT afterglow confirmation
  63. GRB 090107B: Swift/UVOT Observations
  64. GRB 090107B: Swift-XRT detection of possible afterglow
  65. GRB 090107B optical observations
  66. Fermi/GBM detection of GRB 081226A
  67. Fermi/GBM detection of GRB 081225
  68. GRB 090107: Swift detection of a burst
  69. GRB 081231: Fermi GBM Detection
  70. GRB 090102: optical decay
  71. VLA radio upper limit on GRB 090102
  72. GRB 090102: GRT Optical Observation
  73. Swift triggered on the HMXB 1A 1118-61
  74. GRB 081229: Fermi GBM detection
  75. GRB 090102: Hobby-Eberly Telescope Spectroscopy
  76. GRB 090102: P60 Imaging and P200 Spectroscopy
  77. GRB 090102 Observations from IAC80
  78. GRB 090102: GROND observations of the optical afterglow
  79. Swift UVOT observations of GRB 090102
  80. GRB 090102: Swift XRT refined analysis
  81. GRB 090102: NOT redshift
  82. GRB 090102: Enhanced Swift-XRT position
  83. GRB 090102: TAROT Calern observatory optical light curve
  84. GRB 090102: REM observations of a bright afterglow
  85. GRB 090102: Swift detection of a burst with an optical counterpart
  86. GRB 081230: GROND confirmation of the afterglow
  87. GRB081230: Swift-XRT refined analysis
  88. GRB 081230 Swift/UVOT Observations
  89. GRB 081230: Enhanced Swift-XRT position
  90. GRB 081230: Swift/UVOT Detection of an Optical Afterglow
  91. GRB 081230: ROTSE-III Detection of Optical Counterpart
  92. GRB 081230: Swift detection of a burst
  93. GRB 081228: GROND confirmation of the optical/NIR afterglow
  94. GRB 081226C: Fermi GBM detection
  95. VLA radio detection of GRB 081221
  96. GRB 081228: Swift/UVOT Upper Limits
  97. GRB 081228: Swift-XRT Team refined analysis
  98. GRB 081228: detection by GROND
  99. GRB 081228: Enhanced Swift-XRT position
  100. GRB 081228: TAROT Calern observatory optical 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