Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. 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"

37329 results found.

  1. GRB 241115B: Fermi GBM Final Real-time Localization
  2. EP241113a: No Detection in Fermi-GBM Observations
  3. Swift GRB 241115A: Global MASTER-Net observations report
  4. Fermi GRB 241115A: Global MASTER-Net observations report
  5. GRB 241115A: Swift detection of a burst
  6. GRB 241115A: Fermi GBM Final Real-time Localization
  7. GRB 241113B: KAIT Optical Afterglow Candidate
  8. LIGO/Virgo/KAGRA S241114bi: Upper limits from Fermi-GBM Observations
  9. LIGO/Virgo/KAGRA S241114bi: Coverage and upper limits from MAXI/GSC observations
  10. GRB 241113A: Swift-BAT refined analysis
  11. GRB 241113A: PRIME near-infrared upper limits
  12. Fermi GRB 241114A: Global MASTER-Net observations report
  13. GRB 241114A: Fermi GBM Final Real-time Localization
  14. GRB 241113B: J-band upper limit from WINTER
  15. GRB 241113A: J-band observations with WINTER
  16. GRB 241030A: LCO optical observation
  17. GRB 241113B: Swift-XRT observations
  18. GRB 241113A: 1.6m Mephisto and 50cm array optical upper limits
  19. GRB 241113A: KAIT optical observations
  20. EP241113b/GRB 241113B: EP detection of GRB 241113B
  21. GRB 241113B: SVOM/GRM observation
  22. GRB 241113A: Swift-XRT refined Analysis
  23. GRB 241113A: Swift/UVOT Detection
  24. GRB 241113A: REM detection of the optical/NIR afterglow
  25. Konus-Wind detection of GRB 241107A (short/hard)
  26. Fermi Gamma-ray Burst Monitor trigger 753166198/241113201 is not a GRB
  27. GRB 241113B: Swift ToO observations
  28. GRB 241113A: LCO optical observations
  29. GRB 241112B: GMG Optical Upper Limit
  30. GRB 241113A: Enhanced Swift-XRT position
  31. GRB241113A: LCOGT (40-cm) optical counterpart detection
  32. GRB 241113B : detection of a long GRB by SVOM/ECLAIRs
  33. GRB 241113A: MASTER010615.66-224018.2 optical counterpart detection
  34. GRB 241113A: Swift detection of a burst with an optical counterpart
  35. GRB 241105A: ATCA Radio Upper Limits
  36. GRB 241112B: AbAO optical upper limit
  37. GRB 241107A: GROWTH-India telescope optical upper limit
  38. Fermi GRB 241112A: Global MASTER-Net observations report
  39. Fermi-GBM Sub-Threshold Detection of GRB 241112B
  40. GRB 241112B: Optical afterglow detection confirmation in revisiting the Mephisto data
  41. GRB 241112B: Swift-XRT afterglow detection
  42. GRB 241112B: LCO optical detection of the SVOM/VT candidate
  43. GRB 241112B: SVOM/GRM observation
  44. GRB 241112B: SVOM/VT afterglow detection
  45. Fermi Gamma-ray Burst Monitor trigger 752995908/241111230 (GRB 241111A) is not a GRB
  46. GRB 241107A: Swift/BAT candidate arcminute localization of a short burst
  47. GRB 241112B: Mephisto optical upper limits
  48. GRB 241112B: GOTO optical upper limits
  49. GRB 241112B: Swift ToO observations
  50. GRB 241112B : detection of a long GRB by SVOM/ECLAIRs
  51. GRB 241107A: INTEGRAL IBIS localization
  52. GRB 241112A: Fermi GBM Final Real-time Localization
  53. GRB 241105A: VLT/FORS2 refined spectroscopic redshift z = 2.681
  54. IPN triangulation of GRB 241107A (short/hard)
  55. GRB 241107A: INTEGRAL/IBIS/PICsIT detection of a short burst
  56. GRB 241025C: VZLUSAT-2 detection
  57. GRB 241025A: VZLUSAT-2 detection
  58. GRB 241018A: cubesat Avion detection
  59. GRB 241111A: Fermi GBM Final Real-time Localization
  60. GRB 241030B: TESS detection of optical counterpart
  61. LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations
  62. EP241109a: KAIT photometry and 3 m Shane spectroscopy from Lick observatory
  63. EP241107a: AbAO optical upper limit
  64. LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations
  65. GRB 241108A: Further COLIBRÍ Upper Limits on the Optical Counterpart
  66. GRB 241108A: Swift-XRT observations
  67. EP241107A: MASTER optical observations of xray transient
  68. EP241107a: KAIT optical observations
  69. GRB 241108A: Swift ToO observations
  70. GRB 241030A: TESS observations
  71. GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
  72. GRB 241108A : a likely weak long GRB detected by SVOM/ECLAIRs
  73. EP241107a: Kinder optical follow-up observations
  74. GRB 241025A: radio detection with the VLA
  75. GRB 241104A: CALET Gamma-Ray Burst Monitor detection
  76. EP241107a: AKO Optical Afterglow Follow-Up Observations
  77. GRB 241107A: SVOM/GRM detection of a short burst
  78. GRB 241105A: EP-FXT follow-up observations
  79. GRB 241105A: SVOM/GRM observation
  80. EP241107a: OHP/T193 photometric and spectroscopic observations
  81. GRB 241105a: PRIME near-infrared upper limits
  82. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  83. GRB 241025A: LBT optical observations
  84. GRB241105A: Gemini-South Optical Afterglow Detection
  85. GRB 241105A: VLT/FORS2 optical afterglow rapid fading
  86. GRB 241105A: Swift/UVOT Detection
  87. EP241101a: CrAO ZTSH optical observations
  88. GRB 241105A: Swift/BAT-GUANO refined analysis of short burst with extended emission
  89. GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
  90. GRB 241105A: BOOTES-7 optical detection
  91. GRB 241030A: Mondy optical observations
  92. GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  93. Konus-Wind detection of GRB 241105A (short with extended emission)
  94. Konus-Wind detection of GRB 241021A
  95. GRB 241105A: SVOM/VT optical afterglow observations
  96. GRB 241105A: Swift-XRT afterglow detection
  97. GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.681
  98. GRB 241104A: Swift-XRT observations
  99. GRB 240511A: LCO upper limits
  100. GRB 241104A: Fermi GBM 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