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"

16197 results found.

  1. GRB 130215A: P60 Observations
  2. GRB 130215A: Redshift estimate
  3. GRB 130215: ROTSE-III Detection of Optical Counterpart
  4. GRB 130131B: CTIO 0.9-m optical upper-limits
  5. GRB 121128A: optical observations
  6. GRB 121123A: optical observations
  7. GRB 130211A: Swift/UVOT Upper Limits
  8. GRB 130131A: MITSuME Akeno Optical upper limits
  9. GRB 130131B: MITSuME Akeno Optical upper limits
  10. GRB 130122A: PTF P48 optical upper limits
  11. GRB 130206A: XRT and UVOT follow-up observations.
  12. GRB 130131B: optical upper limit in Mondy observatory
  13. GRB 130206A: Zadko observatory - Gingin optical observations
  14. GRB 130131A: optical observation in Mondy observatory
  15. GRB 130131A: Swift/UVOT Upper Limits
  16. GRB 130131A: RATIR optical and infrared upper limits
  17. GRB 130131A: RAPTOR Limits During Gamma-Ray Emitting Interval
  18. GRB 130131B: VLT/X-shooter acquisition camera limits
  19. GRB 130131B: Swift/UVOT Upper Limits
  20. GRB 130131B: MITSuME Okayama optical upper limits
  21. GRB 130131A: MITSuME Okayama optical upper limits
  22. GRB 130131B: TAROT Calern observatory optical observations
  23. GRB 130131B: Zadko observatory - Gingin optical observations
  24. GRB 130131A - Faulkes Telescope North Observations
  25. GRB 130122A: RTT150 optical observations
  26. GRB 130122A: optical observations
  27. GRB 130122A: RATIR Detection
  28. GRB 130122A: Xinglong optical upper limit
  29. GRB 130122A: MASTER-Net early marginal detection of the OT
  30. GRB 130122A: Swift detection of a burst with an optical counterpart
  31. Short GRB 121226A: TNG observation of the host galaxy
  32. GRB 130102B: MASTER synchronous observations
  33. GRB 130102A: Swift/UVOT Upper Limits
  34. GRB 130102A: MASTER-Net optical observations
  35. GRB 130102A: IAC80 I-band observations
  36. GRB 121226A: 5.8 GHz VLA observations
  37. GRB 121229A: Swift/UVOT Upper Limits
  38. Skynet/PROMPT observations of GRB121229a
  39. GRB 121226A: 10.4m GTC optical observations
  40. GRB 121226A: Swift/UVOT Upper Limits
  41. GRB 121226A: NOT optical upper limit
  42. GRB 121226A: Optical Observations
  43. GRB 121226A: MITSuME Okayama Optical upper limits
  44. GRB 121226A: Zadko observatory - Gingin optical observations
  45. GRB 121226A: BOOTES-4/MET optical observations
  46. GRB 121217A: ATCA 44GHz upper limit
  47. GRB 121217A: Swift/UVOT Detection
  48. GRB 121209A: LOAO Observation
  49. GRB 121209A: Swift/UVOT Upper Limits
  50. GRB 121212A: PdBI mm observations
  51. GRB121212A: NOT optical imaging
  52. GRB 121211A: Continued RATIR Optical and NIR Observations, Fading
  53. GRB 121212A: Maidanak optical observations
  54. GRB 121211A: RATIR Optical and NIR Observations
  55. GRB 121212A: RAPTOR Limits During Gamma-Ray Emitting Interval
  56. GRB 121211A: RAPTOR Limits During Gamma-Ray Emitting Interval
  57. GRB 121212A: optical observations in ISON-NM observatory
  58. GRB 121211A: MITSuME Okayama Optical Observation
  59. GRB 121211A: Keck/LRIS redshift
  60. GRB 121211A - Faulkes Telescope North afterglow confirmation
  61. GRB 121211A: Swift detection of a burst with an optical counterpart
  62. GRB 121209A: Keck observations
  63. GRB 121209A: CARMA 3mm Observations
  64. GRB 121209A: EVLA Observations
  65. GRB121209A: RATIR Optical and NIR Upper Limits
  66. GRB 121209A: GROND optical afterglow candidate
  67. GRB 121209A: Gemini-South imaging
  68. GRB 121128A: Optical Observations
  69. GRB 121202A: Swift/UVOT Upper Limits
  70. GRB 121202A: TAROT Calern observatory optical observations
  71. GRB 121201A: GROND afterglow observations and photometric redshift
  72. GRB 121201A: BOOTES-4 optical observations
  73. GRB 121201A: a GRB with an optical counterpart
  74. GRB 121128A: optical observation in Mondy observatory
  75. GRB 121128A: MITSuME Akeno Optical upper limits
  76. GRB 121125A: optical upper limit
  77. GRB 121128A: optical observation in Mondy observatory
  78. GRB 121128A: WSRT radio observation
  79. GRB 121128A: RAPTOR Detection During Gamma-Ray Emitting Interval
  80. GRB 121128A, Swift-BAT refined analysis
  81. GRB 121128A: FTN optical afterglow confirmation
  82. GRB 121128A: Swift detection of a burst with an optical counterpart
  83. GRB 121123A: Swift/UVOT Observations
  84. GRB 121125A: LOAO Observation
  85. GRB 121125A: MASTER-NET optical observations
  86. GRB 121125A: Swift detection of a burst with optical counterpart
  87. GRB 121123A: GROND observations
  88. GRB 121123A: optical observations
  89. GRB 121123A: BOOTES-4 and IAC80 optical observations
  90. GRB 121123A: NOT optical observations
  91. GRB 121123A: MASTER-NET optical limit
  92. GRB 121123A: GMG optical observation
  93. GRB 121123A: Swift detection of a burst with optical counterpart
  94. GRB 121108A: optical upper limit
  95. GRB 121117A: Optical observations
  96. GRB 121117A: optical upper limit
  97. GRB 121117A: Swift/UVOT Observations
  98. GRB 121117A: MASTER prompt optical limit
  99. GRB 121117A: ROTSE-III Optical Limits
  100. GRB 121117A: BOOTES-3 early 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