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"
  1. LIGO/Virgo S190517h: HAWC follow-up
  2. LIGO/Virgo S190517h: MAXI/GSC Observations
  3. LIGO/Virgo S190517h Global MASTER-Net observations report
  4. GRB 190515A: CALET Gamma-Ray Burst Monitor detection
  5. LIGO-Virgo S190517h: AGILE GRID observations
  6. LIGO/Virgo S190517h: IceCube Neutrino Search
  7. LIGO/Virgo S190517h: AGILE MCAL observations
  8. LIGO/Virgo S190517h: INTEGRAL/SPI-ACS prompt observation
  9. LIGO/Virgo S190517h: Identification of a GW compact binary merger candidate
  10. Fermi GRB190517.1 Global MASTER-Net observations report
  11. GRB 190515B: Swift/UVOT Upper Limits
  12. GRB 190515B: BOOTES-4/MET and 2.2m CAHA optical limits
  13. LIGO/Virgo S190513bm: Swope follow-up observations
  14. Fermi GRB190515.49 Global MASTER-Net observations report
  15. GRB 190515B: Swift-BAT refined analysis
  16. GRB 190515A: Insight-HXMT/HE detection
  17. GRB 190515A: Fermi GBM detection
  18. GRB 190515B: Swift-XRT refined Analysis
  19. GRB 190515A: Fermi-LAT detection
  20. Fermi GRB190515.43 Global MASTER-Net observations report
  21. GRB 190515B: Optical observations from OSN
  22. GRB 190515B: Enhanced Swift-XRT position
  23. GRB 190515B: Kitab Observatory optical upper limit
  24. Correction to GRB name for Swift trigger 903845
  25. GRB 190515B: Prompt enhanced Swift-XRT position
  26. GRB 190515B: Swift detection of a burst
  27. GRB 190510A: CALET Gamma-Ray Burst Monitor detection
  28. LIGO/Virgo S190426c: AMI-LA radio observations of ZTF19aassfws
  29. GRB 190515A: Fermi GBM Final Real-time Localization
  30. LIGO/Virgo S190513bm : TAROT-Calern and TAROT-Chile (TCA/TCH)/GRANDMA observation report.
  31. LIGO/Virgo S190513bm: CALET Observations
  32. Fermi GRB190514.67 Global MASTER-Net observations report
  33. LIGO/Virgo S190513bm: Lick/KAIT Follow-Up Observations
  34. LIGO/Virgo S190503bf: Gaia Photometric Alerts transient candidate
  35. LIGO/Virgo S190510g: Gaia Photometric Alerts transient candidate
  36. LIGO/Virgo S190513bm: Swift/BAT Counterpart Search
  37. LIGO/Virgo S190513bm: Insight-HXMT/HE observation
  38. LIGO/Virgo S190510g: Swift-XRT observations and results
  39. LIGO/Virgo S190510g: DECam-GROWTH optical counterpart candidate DG19qcso
  40. LIGO/Virgo S190513bm: ANTARES neutrino search
  41. GRB 190510B: AstroSat CZTI detection
  42. LIGO/Virgo S190513bm: Fermi GBM Observations
  43. GRB 180416D: AstroSat CZTI detection
  44. LIGO/Virgo S190510g: AT2019ezb and AT2019far 10.4m GTC spectroscopy
  45. Konus-Wind observation of GRB 190511A
  46. Konus-Wind observation of GRB 190510A
  47. LIGO/Virgo S190513bm: Fermi-LAT search for a high-energy gamma-ray counterpart
  48. LIGO/Virgo S190512at: CALET Observations
  49. LIGO/Virgo S190513bm: MAXI/GSC Observations
  50. LIGO/Virgo S190510g: Further KMTNet observation of DECam-GROWTH and DESGW candidates
  51. LIGO/Virgo S190513bm: AGILE GRID observations
  52. LIGO/Virgo S190513bm: INTEGRAL prompt observation
  53. LIGO/Virgo S190513bm: AGILE MCAL observation
  54. LIGO/Virgo S190513bm Global MASTER-Net observations report
  55. LIGO/Virgo S190513bm: IceCube Neutrino Search
  56. LIGO/Virgo S190513bm: HAWC follow-up
  57. LIGO/Virgo S190513bm: Identification of a GW compact binary merger candidate
  58. LIGO/Virgo S190512at: Insight-HXMT/HE observation
  59. GRB 190512A: Swift-BAT refined analysis
  60. LIGO-Virgo S190512at: AGILE GRID observations
  61. LIGO/Virgo S190512at: Swift/BAT Counterpart Search
  62. LIGO/Virgo S190510g: Pan-STARRS and ATLAS observations and candidates
  63. LIGO/Virgo S190512at: ANTARES neutrino search
  64. LIGO/Virgo S190512at: Fermi-LAT search for a high-energy gamma-ray counterpart
  65. LIGO/Virgo S190512at: MAXI/GSC Observations
  66. LIGO/Virgo S190512at: Fermi GBM Observations
  67. LIGO/Virgo S190512at Global MASTER-Net observations report
  68. LIGO/Virgo S190510g: Spectroscopic Classification of DECam-GROWTH and DES-GW Candidate DG19fqqk/desgw-190510c with Magellan
  69. GRB 190512A: Fermi GBM observation
  70. LIGO/Virgo S190510g: MASTER OT detection inside PGC087378 galaxy
  71. LIGO/Virgo S190512at: INTEGRAL inactive at the time of the event
  72. LIGO-Virgo S190512at: AGILE MCAL observations
  73. Fermi GRB190512.62 Global MASTER-Net observations report
  74. Fermi GRB190512.61 Global MASTER-Net observations report
  75. LIGO/Virgo S190512at: IceCube Neutrino Search
  76. LIGO/Virgo S190512at: Identification of a GW compact binary merger candidate
  77. GRB 190511A: Swift-BAT refined analysis
  78. GRB 190512A: Swift detection of a burst
  79. GRB 190512A: Fermi GBM Final Real-time Localization
  80. GRB 190511A: Swift-XRT refined Analysis
  81. IPN triangulation of GRB 190510A (short)
  82. LIGO/Virgo S190510g: DOAO Observation
  83. LIGO/Virgo S190510g: CALET Observations
  84. GRB 190511A: Swift/UVOT Detection
  85. LIGO/Virgo S190510g: KMTNet observation of DECam-GROWTH and DESGW candidates
  86. GRB 190511A: NOT optical afterglow
  87. LIGO/Virgo S190510g: OT MASTER142812.05-013615.2 retraction as the kilonova candidate in GCN 24490
  88. LIGO/Virgo S190510g: MASTER OT detection inside low surface brightness galaxy
  89. LIGO/Virgo S190510g: Update on candidate significance
  90. LIGO/Virgo S190510g: Las Cumbres Observatory Galaxy Targeted Counterpart Search
  91. LIGO/Virgo S190510g: Non-detection of the OT in PGC 094244
  92. LIGO/Virgo S190426c: VLA Follow-Up Observations of ZTF19aassfws
  93. LIGO/Virgo S190510g: GRAWITA REM and Loiano optical observations
  94. LIGO/Virgo S190510g: GRAWITA VST-ESO PARANAL optical observations
  95. GRB 190511A: Fermi-LAT detection
  96. GRB 190511A: Fermi GBM observation
  97. GRB 190511A: Enhanced Swift-XRT position
  98. LIGO/Virgo S190510g: DESGW counterpart candidates over 80% of the GW localization area
  99. LIGO/Virgo S190510g : Xinglong-60cm upper limit of the GRAWITA REM's OT
  100. LIGO/Virgo S190510g: MASTER OT independ detection in WISE J060606.26-353233.9 galaxy at desgw-190510a position.

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