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"

16286 results found.

  1. V404 Cyg activity (Swift, Fermi, INTGRAL, KONUS, MAXI detection): optical observations in TSHAO, Khureltogot, and AAO
  2. GRB 150627A: MASTER-SAAO OT Detection
  3. GRB 150627A: Swift/UVOT Detection
  4. GRB 150626B: Swift/UVOT Upper Limits
  5. GRB 150626B: NOT optical upper limits
  6. GRB 150626B: MASTER observations
  7. GRB 150626A: Swift/UVOT Upper Limits
  8. V404 Cyg: MASTER Swift, Integral alert observations
  9. GRB 150616A: Watcher optical upper limit
  10. GRB 150616A: Swift/UVOT Upper Limits
  11. V404 Cyg outburst (Swift trigger 643949 ): TSHAO optical observations
  12. Optical follow-up of Swift trigger on V404 Cyg
  13. GRB 150608A: MITSuME Akeno optical upper limits
  14. GRB150607A: AAO and CrAO optical observations
  15. GRB150607A: Discovery Channel Telescope Optical Observations
  16. GRB 150607A: NOT optical observations
  17. GRB 150607A: Swift detection of a burst with an optical counterpart
  18. GRB 150518A: possible SN observations
  19. GRB 150527A: Continued RATIR Observations
  20. GRB 150530A: RATIR Optical Observations
  21. GRB 150530A: Swift/UVOT Upper Limits
  22. GRB 150527A: MITSuME Okayama upper limits
  23. GRB 150527A: Swift/UVOT Upper Limits
  24. GRB150527A: REM - NIR afterglow
  25. GRB 150523A: Swift/UVOT Detection
  26. GRB 150523A: LCOGT FTS afterglow confirmation
  27. GRB 150523A: LCOGT Cerro-Tololo optical afterglow candidate
  28. GRB 150518A: Continued RATIR optical observations
  29. GRB 150518A: MITSuME Akeno Optical observation
  30. GRB 150518A: Mondy optical observations
  31. GRB 150518A: AMI 15 GHz detection of possible radio counterpart
  32. GRB 150518A: MASTER-net before, early and after optical stereoscopic observations with possible MP discovery inside MAXI error box
  33. GRB 150518A: SAO RAS optical observations
  34. GRB 150518A: VLT/X-shooter redshift of the likely host galaxy
  35. GRB 150518A: RATIR optical observations
  36. GRB 150518A: GMG observation
  37. GRB 150518A: Xinglong2.16m optical afterglow detection
  38. GRB 150514A: VLT/X-shooter redshift
  39. GRB 150512A: CrAO optical observations
  40. GRB 150512A: iPTF Optical Observations
  41. GRB 150424A: 9.8 GHz VLA detection
  42. GRB 150423A: GMG observation limit
  43. GRB 150423A: Chandra X-ray Observation
  44. GRB 150430A: Swift/UVOT Upper Limits
  45. GRB 150428B: Swift/UVOT Upper Limits
  46. GRB 150428A: Swift/UVOT Upper Limits
  47. GRB 150413A: CrAO optical observations
  48. GRB 150428C: MASTER-net automatic optical inspection
  49. GRB 150428B: MASTER-net prompt optical observation
  50. GRB 150428A: MASTER-net early optical observation
  51. GRB 150428A: Danish1.56m optical observations
  52. GRB 150428A: RATIR optical observations
  53. GRB 150423A: MITSuME Akeno Optical observation
  54. GRB 150424A: RATIR Observations
  55. GRB 150424A: 10.4m GTC spectroscopy
  56. GRB 150424A: GROND detects strong fading
  57. GRB 150424A: NOT optical observations
  58. GRB 150423A: VLT/X-shooter spectroscopy and tentative redshift
  59. GRB 150423A: Continued RATIR optical afterglow monitoring
  60. GRB 150424A: Swift/UVOT Observations
  61. GRB 150423A: TSHAO optical observations
  62. GRB 150424A: Keck detection of optical afterglow
  63. GRB 150423A: Keck redshift of neighboring galaxy
  64. GRB 150423A: MITSuME Okayama upper limits
  65. GRB 150423A: Swift/UVOT Upper Limits
  66. GRB 150423A: VLT detection
  67. GRB 150423A: RATIR optical afterglow monitoring
  68. GRB 150423A: Keck optical afterglow confirmation
  69. GRB 150423A: GROND afterglow candidate
  70. GRB 150423A: KAIT Optical Upper Limit
  71. GRB 150413A: Swift-XRT observations
  72. GRB 150413A: RTT150 optical observations
  73. GRB 150413A: ISON-Ussuriysk optical observations
  74. GRB 150413A: MITSuME Akeno Optical observation
  75. LOAO B, R Observations of GRB150413A
  76. GRB 150413A: GMG observation
  77. GRB 150413A: AMI 15 GHz detection of possible radio counterpart
  78. GRB 150413A: additional P60 observations
  79. GRB 150413A : Virtual Telescope optical observations
  80. GRB 150413A
  81. GRB 150413A: Bassano Bresciano Observatory optical observations
  82. GRB 150413A: T7 and T18 optical observations
  83. GRB150413A, optical observations
  84. GRB 150413A: optical observations
  85. GRB 150413A: redshift determination with the 2.2m CAHA
  86. GRB 150413A: P60 photometry
  87. GRB 150413A: Khureltogot optical observations
  88. GRB 150413A: Nanshan optical and radio follow-ups
  89. GRB 150413A: Khureltogot optical observations
  90. GRB 150407A: optical observations
  91. GRB 150403A: MASTER-net optical observation
  92. GRB 150404A: Fermi GBM detection
  93. Fermi trigger 449861706: MASTER-SAAO possible candidate to OT of Short GRB
  94. GRB 150403A: VLT/X-shooter redshift
  95. GRB 150323C: CrAO optical observations
  96. GRB 150323C: additional optical observations in Mondy
  97. GRB 150323C: Khureltogot optical observations
  98. GRB 150403A: Swift detection of a burst with an optical counterpart
  99. GRB 150402A: RATIR Optical Observations
  100. GRB 141121A: GMG observation

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