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"

20994 results found.

  1. GRB241030A: OHP/T193 optical observations
  2. EP241101a: EP-WXT detection of a fast X-ray transient
  3. Swift GRB 241101A: Global MASTER-Net observations report
  4. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  5. EP241021a: Upper limit from Konus-Wind observations
  6. GRB 241030A: further SAO RAS optical observations
  7. GRB 241030A: Optical Observations via Virtual Telescope Project
  8. EP241021a: Liverpool Telescope optical follow-up observations
  9. GRB 241026A: SAO RAS optical observations
  10. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  11. EP241021a: OHP/T193 optical observations
  12. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  13. GRB 241030B: Montarrenti Observatory optical upper limit
  14. GRB 241030A / EP241030a: FTW Optical and NIR observations of the optical counterpart
  15. Fermi trigger No 752083996: Global MASTER-Net observations report
  16. GRB 241030A: SAO RAS optical observations
  17. EP241021a: AMI-LA radio detection
  18. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  19. GRB 241030B: Swift/UVOT Detection
  20. EP EP241030a: Global MASTER-Net observations report
  21. GRB 241029A: LCO optical detection
  22. Fermi trigger No 752006065: Global MASTER-Net observations report
  23. Swift GRB241030.77: Global MASTER-Net observations report
  24. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  25. GRB 241030B: SVOM/VT optical afterglow observations
  26. GRB 241030B: BTA observations
  27. GRB 241029A: SVOM/VT optical afterglow observations
  28. GRB 241030B: optical observations from the INAF Asiago Observatory
  29. GRB241030B: GRANDMA/TAROT Upper Limit
  30. GRB 241030B: SAO RAS optical observations
  31. GRB 241030B: Nanshan/HMT optical afterglow detection
  32. GRB 240912A: radio detection with the VLA
  33. Fermi GRB 241030A: Global MASTER-Net observations report
  34. Swift GRB 241030A: Global MASTER-Net observations report
  35. GRB 241030A: Swift/UVOT Detection
  36. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  37. GRB 241030A: SVOM/C-GFT optical observations
  38. GRB 241026A: LBT optical observations
  39. EP241021a: Optical rebrightening observations with Mephisto
  40. GRB 241030A: Multiband optical detection with Mephisto
  41. GRB 241030A: SVOM/VT optical afterglow observations
  42. GRB 241025A: The discovery of a BdHN I from data of Swift, Fermi, SVOM and Einstein Probe telescopes
  43. GRB 241030A: TRT optical observations
  44. GRB 241030A: Keck/LRIS spectroscopic redshift z = 1.411
  45. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  46. GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
  47. GRB 241029A: SAO RAS optical observations
  48. GRB 241026A: SAO RAS optical observations
  49. EP240919a / GRB 240919A: ATCA Detection of Radio Counterpart
  50. EP241021a: SAO RAS observations of rebrightening
  51. EP241021a: ATCA radio observations
  52. MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
  53. GRB 241026A: Swift/UVOT Upper Limits
  54. GRB 241029A: Swift-XRT observations
  55. GRB 241029A: GOTO optical afterglow detection
  56. EP241021a: continued SOAR observations confirm optical rebrightening
  57. GRB 241029A: MASTER early optical counterpart detection
  58. GRB 241029A: Xinglong-2.16m optical afterglow confirmation
  59. GRB 241029A: Mephisto observations
  60. EP 241026b: LBT possible optical counterpart (brightening source)
  61. GRB 241029A: TRT optical afterglow candidate detection
  62. GRB 241029A: Swift ToO observations
  63. Fermi trigger No 751861204: Global MASTER-Net observations report
  64. GRB 240821A: Keck/LRIS spectroscopic observations
  65. GRB 241025A (EP241025a): Optical afterglow observations with the Tsinghua-Nanshan Optical Telescope
  66. GRB 241026A: LBT redshift confirmation
  67. GRB 241025A: further SAO RAS optical observations
  68. GRB 241026A: BTA and Zeiss-1000 optical observations
  69. EP241026B: GROWTH-India Telescope optical upper limit
  70. GRB 241025A: Swift/UVOT Detection
  71. GRB 241026A: GROWTH-India Telescope optical observations
  72. GRB 241026A: J-band observations with WINTER
  73. GRB 241025A: SAO RAS optical observations
  74. GRB 241025A: Mondy optical observations
  75. EP241021a: SOAR observations of the optical counterpart
  76. EP241021a: further SAO RAS optical observations
  77. EP 241026b: LBT optical observations
  78. EP241021a: e-MERLIN radio observation
  79. EP EP241026b: Global MASTER-Net observations report
  80. GRB 241026A: KAIT optical observations
  81. EP241026b: EP detection of a fast X-ray transient
  82. Fermi trigger No 751616906: Global MASTER-Net observations report
  83. GRB 241026A: COLIBRÍ Detection of the Optical Counterpart
  84. GRB 241026A: SAO RAS observations of possible optical afterglow
  85. Fermi GRB 241026A: Global MASTER-Net observations report
  86. Swift GRB241026.95: Global MASTER-Net observations report
  87. GRB241025A: 1.3m DFOT optical afterglow detection
  88. EP241021a: optical follow-up observations with Xinglong Observatory
  89. ​GRB 241025A: optical photometry from Konkoly
  90. GRB 241025A: GROWTH-India Telescope optical observations
  91. GRB 241025A: COLIBRÍ Detection of the Afterglow
  92. GRB 241025A: GRANDMA and Kilonova-Catcher optical afterglow detections and upperlimits
  93. Fermi trigger No 751563375: Global MASTER-Net observations report
  94. Fermi trigger No 751554401: Global MASTER-Net observations report
  95. EP241021a: Optical and NIR observations of counterpart with the Fraunhofer Telescope at Wendelstein Observatory
  96. EP241021a: Optical and NIR observations of counterpart with the Fraunhofer Telescope at Wendelstein Observatory
  97. EP 241021a: Swift-XRT observations
  98. EP241021a: optical follow-up observations with the Liverpool Telescope
  99. Fermi GRB 241025A: Global MASTER-Net observations report
  100. Swift GRB 241025A: 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