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"

12394 results found.

  1. EP241101a: Optical upper limits with Kinder observations
  2. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  3. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  4. EP241103a: GSP optical upper limit
  5. EP241103a: Global MASTER-Net observations report
  6. EP241101a: Global MASTER-Net observations report
  7. EP241101a: BOOTES-7 optical upper limit
  8. EP241101a: EP-WXT detection of a fast X-ray transient
  9. Swift GRB 241101A: Global MASTER-Net observations report
  10. EP241021a: Upper limit from Konus-Wind observations
  11. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  12. GRB 241030B: Montarrenti Observatory optical upper limit
  13. EP241026b: Liverpool Telescope optical follow-up
  14. Fermi trigger No 752083996: Global MASTER-Net observations report
  15. GRB 241030B : GIT optical upper limits
  16. GRB 241030B: LCOGT Optical Upper Limits
  17. GRB 241030B: Swift/UVOT Detection
  18. EP EP241030a: Global MASTER-Net observations report
  19. Fermi trigger No 752006065: Global MASTER-Net observations report
  20. Swift GRB241030.77: Global MASTER-Net observations report
  21. GRB 241030B : MITSuME Akeno optical upper limits
  22. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  23. GRB 241030B: optical observations from the INAF Asiago Observatory
  24. GRB241030B: GRANDMA/TAROT Upper Limit
  25. Konus-Wind detection of GRB 241030A
  26. GRB 241030B: Swift detection of a burst
  27. Fermi GRB 241030A: Global MASTER-Net observations report
  28. Swift GRB 241030A: Global MASTER-Net observations report
  29. MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
  30. GRB 241026A: Swift/UVOT Upper Limits
  31. GRB 241029A: Swift-XRT observations
  32. Fermi trigger No 751861204: Global MASTER-Net observations report
  33. EP241026B: GROWTH-India Telescope optical upper limit
  34. GRB 241025A: Swift/UVOT Detection
  35. GRB 241026A: J-band observations with WINTER
  36. EP241021a: e-MERLIN radio observation
  37. EP EP241026b: Global MASTER-Net observations report
  38. Fermi trigger No 751616906: Global MASTER-Net observations report
  39. Fermi GRB 241026A: Global MASTER-Net observations report
  40. Swift GRB241026.95: Global MASTER-Net observations report
  41. LIGO/Virgo/KAGRA S241009l: Upper limits from Swift/BAT-GUANO
  42. Fermi trigger No 751563375: Global MASTER-Net observations report
  43. Fermi trigger No 751554401: Global MASTER-Net observations report
  44. EP 241021a: Swift-XRT observations
  45. Fermi GRB 241025A: Global MASTER-Net observations report
  46. Swift GRB 241025A: Global MASTER-Net observations report
  47. Fermi GRB 241024B: Global MASTER-Net observations report
  48. GRB 241010A: VIRT Optical Upper Limit
  49. Fermi trigger No 751449953: Global MASTER-Net observations report
  50. EP241021a: Optical upper limits with Kinder observations
  51. EP EP241021a: Global MASTER-Net observations report
  52. GRB241017A: 1.3m DFOT optical upper limit
  53. GRB 241018A: 1.3m DFOT Optical upper limit
  54. EP241021a: GOTO optical upper limits
  55. IceCube-Cascade 241019A: Upper limits from a search for additional neutrino events in IceCube
  56. GRB 241018A/sb24101802: Mephisto optical upper limit
  57. GRB 241017A/sb24101702: Mephisto optical upper limit
  58. GRB 241018A: BOOTES-4/MET optical upper limit
  59. GRB 241018A: Mondy optical upper limit
  60. GRB 241018A: GROWTH-India telescope optical upper limit
  61. GRB241018A: XingLong Optical Upper Limit
  62. GRB 241018A: Swift-XRT observations
  63. GRB 241018A: REM optical/NIR upper limits
  64. GRB 241017A: SVOM/VT follow-up and optical upper limit
  65. GRB 241018A: LCO/0.4m optical upper limits
  66. GRB 241006A: VIRT Optical Upper Limit
  67. GRB 240727A: VIRT Optical Upper Limit
  68. GRB 241017A: Swift-XRT observations
  69. GRB 241017A: GROWTH-India Telescope optical upper limit
  70. GRB 241017A: J-band upper limit from WINTER
  71. Fermi trigger No 750788395: Global MASTER-Net observations report
  72. Fermi GRB 241016B: Global MASTER-Net observations report
  73. Fermi GRB 241016A: Global MASTER-Net observations report
  74. IceCube Alert 241016.04: Global MASTER-Net observations report
  75. GRB 241009A: LCO optical upper limits
  76. Fermi GRB 241013B: Global MASTER-Net observations report
  77. Integral GRB241013.04: Global MASTER-Net observations report
  78. GRB 241009A: GRANDMA optical upper limits
  79. GRB 241009A: Swift-XRT afterglow detection
  80. GRB 241006A: ATCA Radio Upper Limits
  81. Fermi trigger No 750211959: Global MASTER-Net observations report
  82. Swift GRB 241010A: Global MASTER-Net observations report
  83. Fermi trigger No 750291012: Global MASTER-Net observations report
  84. GRB 241010A: J-band observations with WINTER
  85. Fermi GRB 241010B: Global MASTER-Net observations report
  86. IceCube-241006A: Upper limits from a search for additional neutrino events in IceCube
  87. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  88. GRB 241002A: NOT optical upper limits
  89. Fermi GRB 241008A: Global MASTER-Net observations report
  90. GRB 241006A: GRANDMA optical upper limits
  91. EP240930a / GRB 240930B: CrAO ZTSH optical upper limit
  92. Fermi-LAT Gamma-ray Observations of NuEm-240926A
  93. GRB 241006A: PRIME near-infrared upper limits
  94. GRB 241006A: Swift/UVOT Upper Limits
  95. GRB 241006A: SVOM/VT follow-up and optical upper limit
  96. IceCube Alert 241006.94: Global MASTER-Net observations report
  97. Swift GRB241006.91: Global MASTER-Net observations report
  98. GRB 240930B: SVOM/C-GFT optical upper limit
  99. Fermi trigger No 749721670: Global MASTER-Net observations report
  100. Fermi trigger No 749735279: Global MASTER-Net observations report

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