Skip to main content
Due to the lapse in federal government funding, NASA is not updating this website. See the Operations FAQ for GCN impacts.
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"

20122 results found.

  1. GRB 060219: Swift/UVOT Upper Limits
  2. GRB 051221B: Swift-XRT Team Refined Analysis
  3. GRB060218: Radio Afterglow Discovery
  4. GRB060219: SDSS pre-burst observations
  5. GRB 060219: Swift-BAT detection of a weak burst
  6. Oddball GRB 060218, transient or GRB?
  7. Brightening of the Optical Counterpart of the Possible GRB 060218
  8. GRB 060218: Pre-burst detection of a possible host galaxy
  9. GRB 060218A: ROTSE-III Possible Optical Flare
  10. GRB 060211B: Swift/UVOT Upper Limits
  11. GRB060218 : SDSS pre-burst observations
  12. GRB 060218: Swift XRT Position
  13. GRB 060213: optical afterglow not confirmed
  14. Swift UVOT observations of GRB060213
  15. GRB060213: Swift XRT observations and possible afterglow candidate
  16. Konus-Wind observation of bright hard GRB 060213
  17. GRB 060213: IPN localization
  18. GRB060211B: REM optical and NIR observations
  19. GRB 060211A: Further refined analysis of the Swift burst
  20. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  21. GRB 060211b: P60 Observations
  22. GRB 060211B: Swift/BAT refined analysis
  23. GRB060210: Swift/UVOT Upper Limits
  24. GRB 060210: Optical Observations
  25. GRB 060211: ROTSE-III Optical Limits
  26. GRB 060211: Swift detection of a long burst
  27. GRB060210: Optical Observations
  28. GRB060210: Early Optical Observations
  29. GRB 060210: optical evolution
  30. GRB 060210: Swift detection of a burst
  31. GRB060210: Optical afterglow
  32. GRB 060209 : TAROT optical observation
  33. GRB 060203: Swift/UVOT upper limits
  34. GRB 060206: TTT Observations
  35. GRB 060121 : WIDGET Pre-trigger limit
  36. GRB060204a: Swift XRT Source is not GRB Afterglow
  37. Orphan GRB Afterglow candidate
  38. GRB 060206: IR Detection of the Afterglow
  39. GRB 060204A: ROSAT Pointing
  40. GRB 060206: Super-LOTIS observations
  41. GRB060204A: Swift/UVOT observations
  42. GRB060206: SDSS Pre-Burst Observations
  43. GRB 060206: High redshift burst
  44. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  45. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  46. GRB060206: Optical afterglow
  47. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  48. GRB060203: WHT Z-band observations
  49. BAT GRB 060204C is probably not a GRB
  50. GRB060204C: optical observation
  51. GRB 060204A: Swift XRT upper limit
  52. GRB 060204A: FRAM optical observations
  53. GRB060204B: Swift/UVOT refined analysis
  54. GRB 060204C: optical observations
  55. Swift XRT Observation of GRB 060204C
  56. GRB 060204B: Swift-BAT refined analysis
  57. GRB 060204B: ART early limit
  58. GRB 060204b: Keck/LRIS Afterglow Confirmation
  59. GRB 060204C: Liverpool Telescopes optical limit
  60. GRB 060204C: ROTSE-III Optical Limits
  61. GRB 060204C: Swift-BAT detection of a burst
  62. GRB060204B, optical observation
  63. GRB060204B - SDSS pre-burst observations
  64. GRB 060204B: Swift detection of a burst
  65. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  66. GRB 060203: RTT150 optical observations
  67. Swift-BAT trigger is GRB 060203
  68. GRB 060203: IR Counterpart
  69. GRB060203: Observations with SARA
  70. GRB 060203: P60 Confirmation of Optical Afterglow
  71. Possible GRB 060203: optical observations at Asiago
  72. GRB 060202: Gemini-N J, H, K_s observations
  73. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  74. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  75. GRB060202, optical observation
  76. GRB 060202: Swift/UVOT upper limits
  77. GRB 060202: Swift detection of a burst
  78. GRB 060121: Gemini Late-time Observations
  79. GRB 060130: PROMPT Observations
  80. GRB060130: Further R-band imaging
  81. GRB 060130: Swift/XRT observation
  82. GRB060130: Optical imaging
  83. GRB060130: REM infrared observations
  84. GRB 060130, SMARTS optical observations
  85. GRB 060130: FRAM optical observations
  86. GRB 060121: Confirmation of NIR Afterglow
  87. GRB 060123: Swift refined analysis of an unusual GRB
  88. GRB060124, BVRcIc field calibration
  89. GRB060105: refined analysis of the Suzaku observation
  90. GRB 060121: Probable Detection of NIR Afterglow
  91. GRB 060116 HST observations
  92. Konus-Wind observation of GRB 060124
  93. GRB 060124: ART optical limits during the burst
  94. GRB060123: Optical and IR Imaging
  95. GRB 060123: P200 Observations
  96. GRB 060124: R band Observations
  97. GRB 060124 : Optical observation at Xinglong and Kiso
  98. GRB060123: SDSS pre-burst observations
  99. GRB 060123: Swift detection of a very long, faint burst
  100. GRB 060121: OHP optical limits

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