Skip to main content
New! October 18 GCN Classic Outage and Schema v4.2.0. 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').

17989 results found.

  1. GRB 241030B: Montarrenti Observatory optical upper limit
  2. EP241026b: Liverpool Telescope optical follow-up
  3. GRB 241030A: SAO RAS optical observations
  4. EP241021a: AMI-LA radio detection
  5. GRB 241030B : GIT optical upper limits
  6. GRB 241030B: LCOGT Optical Upper Limits
  7. GRB 241030A: Swift-BAT refined analysis
  8. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  9. GRB 241030B: Swift/UVOT Detection
  10. GRB 241029A: LCO optical detection
  11. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  12. GRB 241030B : MITSuME Akeno optical upper limits
  13. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  14. GRB 241030B: SVOM/VT optical afterglow observations
  15. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  16. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  17. GRB 241030B: BTA observations
  18. GRB 241029A: SVOM/VT optical afterglow observations
  19. GRB 241030B: Enhanced Swift-XRT position
  20. GRB241030B: GRANDMA/TAROT Upper Limit
  21. GRB 241030B: SAO RAS optical observations
  22. GRB 241030B: AKO Optical Afterglow Detection
  23. GRB 241030B: Nanshan/HMT optical afterglow detection
  24. Konus-Wind detection of GRB 241030A
  25. GRB 241030B: Swift detection of a burst
  26. GRB 240912A: radio detection with the VLA
  27. GRB 241030A: AKO Optical Afterglow Detection
  28. GRB 241030A: Swift/UVOT Detection
  29. GRB 241030A: SVOM/C-GFT optical observations
  30. GRB 241026A: LBT optical observations
  31. EP241021a: Optical rebrightening observations with Mephisto
  32. GRB 241030A: Multiband optical detection with Mephisto
  33. GRB 241030A: SVOM/VT optical afterglow observations
  34. GRB 241030A : MITSuME Akeno optical afterglow detection
  35. GRB 241030A: Enhanced Swift-XRT position
  36. GRB 241029A: GROWTH-India Telescope optical follow up
  37. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  38. GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
  39. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  40. GRB 241029A: SAO RAS optical observations
  41. GRB 241026A: SAO RAS optical observations
  42. EP241021a: SAO RAS observations of rebrightening
  43. GRB 241029A: GTC/OSIRIS+ spectroscopic redshift z=1.072
  44. MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
  45. GRB 241026A: Swift/UVOT Upper Limits
  46. GRB 241029A: AKO Optical Afterglow Detection
  47. EP241021a: continued SOAR observations confirm optical rebrightening
  48. GRB 241029A: Xinglong-2.16m optical afterglow confirmation
  49. GRB 241029A: Mephisto observations
  50. EP 241026b: LBT possible optical counterpart (brightening source)
  51. GRB 241029A: TRT optical afterglow candidate detection
  52. GRB 241026A: the 100th GRB detected by GRBAlpha
  53. GRB 241026A: TNOT optical counterpart detection
  54. Konus-Wind detection of GRB 241025A
  55. GRB 241025A (EP241025a): Optical afterglow observations with the Tsinghua-Nanshan Optical Telescope
  56. GRB 241025A: further SAO RAS optical observations
  57. GRB 241026A: BTA and Zeiss-1000 optical observations
  58. GRB 241026A: SVOM/GRM observation
  59. EP241026B: GROWTH-India Telescope optical upper limit
  60. GRB 241025A: Swift/UVOT Detection
  61. GRB 241026A: GROWTH-India Telescope optical observations
  62. GRB 241026A: J-band observations with WINTER
  63. GRB 241025A: SAO RAS optical observations
  64. GRB 241026A: Las Cumbres optical detection
  65. GRB 241025A: Mondy optical observations
  66. EP241021a: SOAR observations of the optical counterpart
  67. EP241021a: further SAO RAS optical observations
  68. EP 241026b: LBT optical observations
  69. EP241021a: e-MERLIN radio observation
  70. GRB 241026A: Enhanced Swift-XRT position
  71. EP241026b: EP detection of a fast X-ray transient
  72. GRB 241026A: COLIBRÍ Detection of the Optical Counterpart
  73. GRB 241026A: SAO RAS observations of possible optical afterglow
  74. GRB 241026A: Swift detection of a burst
  75. GRB241025A: 1.3m DFOT optical afterglow detection
  76. EP241021a: optical follow-up observations with Xinglong Observatory
  77. GRB 241025A: GROWTH-India Telescope optical observations
  78. GRB 241025A: COLIBRÍ Detection of the Afterglow
  79. GRB 241025C: Fermi GBM Detection
  80. IPN triangulation of GRB 241022A (short/hard)
  81. LIGO/Virgo/KAGRA S241009l: Upper limits from Swift/BAT-GUANO
  82. GRB 241025A: GRANDMA and Kilonova-Catcher optical afterglow detections and upperlimits
  83. GRB 241025A : SVOM/VT optical afterglow observations
  84. EP241021a: Liverpool Telescope optical follow-up observations
  85. GRB 241025A: Enhanced Swift-XRT position
  86. GRB 241025A: DDOTI Afterglow detection
  87. GRB 241025A: TRT optical afterglow observation
  88. GRB 241025A: Swift detection of a burst with an optical counterpart
  89. EP241021a: GTC OSIRIS+ spectroscopy of the optical counterpart
  90. GRB 241001A: ATCA radio observations
  91. GRB 241010A: VIRT Optical Upper Limit
  92. EP241021a: SAO RAS optical observations
  93. EP241021a: KAIT optical observations
  94. EP241021a: EP-FXT follow-up observation update
  95. EP241021a: 1.3m DFOT Optical observations
  96. EP241021a: Optical upper limits with Kinder observations
  97. EP241021a: TRT optical observations
  98. GRB 241018A: SVOM/C-GFT optical observations
  99. EP241021a: NOT likely optical counterpart
  100. GRB241017A: 1.3m DFOT optical upper limit

Advanced

Download all Circulars as a .tar.gz archive:
Looking for U.S. government information and services? Visit USA.gov