Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

16168 results found.

  1. GRB 121024A: Swift detection of a burst with an optical counterpart
  2. GRB 121011A: early optical light curve
  3. GRB 121017A: Swift/UVOT Upper Limits
  4. GRB 121017A: GROND Observations
  5. GRB 121017A: 1.23m CAHA R-band observations
  6. GRB 121017A optical observations
  7. GRB 121017A: BOOTES-2/TELMA observations
  8. GRB 121011A: WSRT radio observation
  9. GRB 121011A: optical observations
  10. GRB 121011A: NOT optical observations
  11. GRB 121011A: optical observations
  12. GRB 121011A: TNG optical observations
  13. GRB 121011A: MASTER-Net early OT light curve
  14. GRB121011A : Xinglong TNT optical observation
  15. GRB 121011A: MITSuME Okayama Optical Observation
  16. GRB 121011A: Swift detection of a burst with optical afterglow
  17. GRB 120927A: optical upper limit
  18. GRB 121001A: GROND Afterglow Confirmation
  19. GRB 121001A: Swift/UVOT Upper Limits
  20. Swift Trigger 535026: Optical decay confirmation with IAC80 and BOOTES-2/TELMA.
  21. GRB 121001A: MASTER optical observations
  22. GRB 121001A: possible optical counterpart
  23. Swift Trigger 535026: ROTSE-III Optical Limits
  24. GRB 120927A: Swift/UVOT Upper Limits
  25. GRB 120923A: optical upper limit
  26. GRB 120923A: RAPTOR Early Afterglow Limits
  27. GRB 120923A: MITSuME Okayama Optical upper limits
  28. GRB 120923A: RAPTOR Limits During Gamma-Ray Emitting Interval
  29. GRB 120922A: GROND photometric redshift
  30. GRB 120922A: Swift/UVOT Detection
  31. GRB 120923A: Swift/UVOT Upper Limit
  32. GRB 120923A: Gemini afterglow detection, high-z candidate
  33. GRB 120922A: TAROT La Silla observatory optical observations
  34. GRB 120923A: TAROT La Silla observatory optical observations
  35. GRB 120923A: ROTSE-III Optical Limits
  36. GRB 120919B: MASTER prompt optical observations
  37. GRB 120919A: Swift/UVOT Upper Limits
  38. GRB 120913B: FRAM early follow up and detection
  39. GRB 120913B: REM NIR early time detection
  40. Continued Skynet/PROMPT observations of GRB120913B
  41. GRB 120913B: TAROT La Silla observatory optical photometry
  42. GRB 120913B: TAROT La Silla observatory optical detection
  43. GRB 120907A: optical observations of ISON-Kislovodsk
  44. GRB 120911A: optical upper limit CrAO
  45. GRB 120911A: optical upper limit ISON-NM
  46. GRB120911A: MITSuME Okayama Optical upper limits
  47. GRB 120911A: Swift/UVOT Upper Limits
  48. GRB 120911A: ROTSE-III Optical Limits
  49. GRB 120908A: Swift Observations
  50. GRB 120909A: TAROT La Silla observatory optical observations
  51. GRB 120909A: Swift/UVOT Detection
  52. GRB 120909A: X-Shooter redshift 3.93
  53. GRB 120907A: EVLA observations
  54. GRB 120907A: NOT optical observations
  55. GRB 120907A MASTER optical observations
  56. GRB 120907A: ROTSE-III Optical Limits
  57. GRB 120907A: Swift detection of a burst with optical counterpart
  58. GRB 120819A: optical upper limit
  59. GRB 120802A: optical observations in CrAO
  60. GRB 120830A: early MASTER optical limit
  61. Fermi trigger 368003226 : MASTER optical observations
  62. GRB 120819A: Swift/UVOT Upper Limits
  63. GRB 120817A: Swift/UVOT Upper Limits
  64. GRB 120817B: Deep limit on the optical afterglow from du Pont and Magellan observations
  65. GRB 120821A: Swift/UVOT Upper Limits
  66. GRB 120811C: optical observations
  67. GRB 120819A: Bassano Bresciano Observatory optical observations
  68. GRB 120819A: MITSuME Ishigakijima upper limits
  69. GRB 120819A: MITSuME Okayama Optical upper limits
  70. GRB 120819A: MASTER optical observations
  71. GRB 120811C: optical observations
  72. GRB 120816A: Swift/UVOT Detection of the Optical Afterglow
  73. GRB 120815A: MASTER-ICATE observations
  74. GRB 120817B: LCO Optical Observations
  75. GRB 120816A: optical upper limit
  76. GRB 120815A: Swift/UVOT Detection of the Optical Afterglow
  77. GRB 120816A: Bassano Bresciano Observatory optical observations
  78. GRB 120816A: BOOTES-2 observations
  79. GRB120816A: OPTIMA discovery of optical counterpart
  80. GRB 120816A: TAROT Calern observatory optical observations
  81. GRB 120816A: ROTSE-III Optical Limits
  82. GRB 120805A: Liverpool Telescope optical candidate detection
  83. GRB 120815A: TAROT La Silla observatory optical observations
  84. GRB 120811A: Swift/XRT-UVOT Obseravations
  85. GRB 120805A: optical afterglow confirmation from the NOT
  86. GRB 120805A: Enhanced Swift-XRT position
  87. GRB 120811C: EVLA Observations
  88. GRB 120811C: RTT150 optical observations
  89. GRB 120811C: MASTER-Tunka OT observations
  90. GRB 120811C: NOT redshift
  91. GRB 120811C: Bassano Bresciano Observatory optical observations
  92. GRB 120811C: RTT150 optical observations
  93. GRB 120811C: TAROT Calern observatory optical observations
  94. GRB 120811C: MASTER-Amur observations of fading OT
  95. GRB 120811C: Swift detection of a burst with an optical counterpart
  96. GRB 120803A: optical upper limit
  97. GRB 120807A: Swift/UVOT Upper Limits
  98. GRB 120714B: GROND/FORS2 detection of a supernova
  99. GRB 120802A: optical observations
  100. GRB 120804A: Gemini-North detection of an optical afterglow and putative host galaxy

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