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"

32766 results found.

  1. GRB 240414A : OHP/T193 second epoch of optical follow-up and afterglow detection
  2. GRB 240414A: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  3. LIGO/Virgo/KAGRA S240413p: No Counterparts in DDOTI/OAN Optical Observations
  4. EP240413A: GOTO optical upper limits
  5. GRB 240414A: Skynet Optical Afterglow Observations
  6. Swift GRB 240414A: Global MASTER-Net observations report
  7. EP240414a: Kinder optical counterpart candidate possibly associated with the galaxy SDSS J124601.99-094309.3
  8. IPN triangulation of GRB 240410A
  9. EP240413a: possible detection of the X-ray emission with EP-FXT after 14 hours
  10. IPN triangulation of GRB 240411A
  11. Fermi-LAT gamma-ray observations of IceCube-240412A
  12. GRB 240414A : MITSuME Akeno optical upper limits
  13. GRB 240414A: Redshift confirmation from GTC/OSIRIS+
  14. GRB 240414A : OHP/T193 redshift determination
  15. GRB 240414A : OHP/T193 optical counterpart detection
  16. LIGO/Virgo/KAGRA S240413p: Updated Sky localization
  17. LIGO/Virgo/KAGRA S240413p: Zwicky Transient Facility observations
  18. EP240408a: GSP optical upper limit
  19. GRB 240411B: CrAO/ZTSh optical observations
  20. GRB 240411B: Kinder observations with Lulin observatory
  21. LIGO/Virgo/Kagra S240413p: NED Galaxies in the Localization Volume
  22. LIGO/Virgo/KAGRA S240413p: Identification of a GW compact binary merger candidate
  23. GRB 240411B: HiPERCAM/GTC observation
  24. GRB 240411B: Swift-BAT refined analysis
  25. GRB 240411B: 1.3m DFOT Optical observations
  26. GRB 240411A: GRBAlpha detection
  27. GRB 240411B: OHP/T193 optical observations
  28. GRB 240405A: Glowbug gamma-ray detection
  29. GRB 240411B: LCO optical afterglow detection
  30. GRB 240408B: GRBAlpha detection
  31. EP240408A: MASTER optical observations
  32. EP240408a: GROND detection of a candidate counterpart
  33. EP240408a: Swift follow-up observation
  34. X-ray transient EP240315a: second epoch e-MERLIN radio observations
  35. GRB 240405A: GRBAlpha detection
  36. IceCube-240327B: GRANDMA/Kilonova-Catcher observations of 4FGL J0555.9+0030 and optical upper limits
  37. Fermi GRB 240408A: Global MASTER-Net observations report
  38. GRB 240402C: CALET Gamma-Ray Burst Monitor detection
  39. Fermi GRB 240407A: Global MASTER-Net observations report
  40. Fermi-LAT gamma-ray observations of IceCube-240327B
  41. Fermi-LAT gamma-ray observations of IceCube-240327A
  42. LXT 240402A/GRB 240402B: rest-frame energetics from Konus-Wind observation
  43. Fermi GRB 240405B: Global MASTER-Net observations report
  44. GRB 240402C: Glowbug gamma-ray detection
  45. GRB 240331A: GRBAlpha detection
  46. LXT 240402A/GRB 240402B: GECAM-C refined analysis
  47. Swift satellite resumes pointed science observations
  48. GRB 240403A: Glowbug gamma-ray detection
  49. LXT 240402A/GRB 240402B: Glowbug gamma-ray detection
  50. X-ray transient LXT 240402A: WFST optical upper limits​
  51. Konus-Wind detection of LXT 240402A/GRB 240402B
  52. GRB/FXT 240402B: Kinder optical counterpart candidate
  53. IceCube-240327B: GRANDMA observations of 4FGL J0555.9+0030
  54. GRB/FXT 240402B: VLT/FORS2 optical afterglow candidate
  55. X-ray transient LXT240402A: AST3-3 optical upper limits
  56. LXT 240402A: EP-FXT detection of the X-ray afterglow
  57. Fermi GRB 240404A: Global MASTER-Net observations report
  58. LXT 240402A: MASTER optical observations with AGN in error-box
  59. GRB 240402B: GWAC-F50A optical upper limit
  60. GRB 240402B: GECAM-C detection
  61. Fermi GRB 240402A: Global MASTER-Net observations report
  62. X-ray transient EP240331a: Kinder optical upper limits
  63. X-ray transient EP240331A: GRANDMA-Kilonova catcher optical upper limit
  64. EP240331A: MASTER optical observations
  65. Transient EP240315a: J-band observations of AT2024eju with WIRC
  66. IceCube-240327B: Upper limits from a search for additional neutrino events in IceCube
  67. IceCube-240327A: Upper limits from a search for additional neutrino events in IceCube
  68. GRB 240329A: Glowbug gamma-ray detection
  69. GRB 240331A: AstroSat CZTI detection
  70. GRB 240329A: AstroSat CZTI detection
  71. GRB 240329A: GRBAlpha detection
  72. Fermi GRB 240329A: Global MASTER-Net observations report
  73. Fermi GRB 240328B: Global MASTER-Net observations report
  74. Fermi GRB 240328A: Global MASTER-Net observations report
  75. X-ray transient EP240315a: continued ATCA monitoring
  76. IceCube-240327B: No candidates from the Zwicky Transient Facility
  77. X-ray transient EP 240315a: Second epoch Chandra observations
  78. X-ray transient EP240315a: e-MERLIN radio observations
  79. X-ray transient EP240315a: Ondrejov D50 optical limit
  80. Transient EPW20240219aa: REM optical/NIR further observations
  81. GRB 240320A: Glowbug gamma-ray detection
  82. GRB 240318A: Fermi GBM Observation
  83. Fermi GRB 240320A: Global MASTER-Net observations report
  84. Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
  85. GRB 240315C / X-ray transient EP240315a: Swift/BAT detection
  86. IPN triangulation of GRB 240315C (consistent with a fast X-ray transient EP240315a)
  87. GRB 240317B: Swift/BAT-GUANO Angular Error Correction
  88. X-ray transient EP 240315a: Chandra observations
  89. X-ray transient EP240315a: GTC/HiPERCAM photometry
  90. X-ray transient EP240315a: MeerKAT radio detection
  91. X-ray transient EP240315a: GTC/OSIRIS spectroscopic redshift confirmation
  92. GRB 240318A: Glowbug gamma-ray detection
  93. X-ray transient EP240315a: PRIME near infrared detection
  94. GRB 240317B: Fermi GBM Observation
  95. X-ray transient EP240315a: 3.6 m TNG NIR detection
  96. Swift satellite in safe mode
  97. X-ray transient EP240315a/AT2024eju: TShAO (Zeiss-1000) observatory optical upper limit
  98. X-ray transient EP240315a: EP-FXT detection of the X-ray afterglow
  99. Fermi GRB 240318A: Global MASTER-Net observations report
  100. GRB 240317A: AstroSat CZTI detection

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