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"

5184 results found.

  1. GRB 190604B: VLT Afterglow Detection
  2. GRB 190604B: Swift-XRT refined Analysis
  3. S190602aq: MASTER OT detection
  4. GRB 190531B: Swift-XRT afterglow detection
  5. GRB 190530A: Swift-XRT afterglow detection
  6. LIGO/Virgo S190425z: No counterpart candidate in Zadko-GRANDMA observations.
  7. LIGO/Virgo S190521r: CNEOST follow-up observations
  8. LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC-F30 observations.
  9. LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC observations.
  10. LIGO/Virgo S190524q Global MASTER-Net observations report
  11. LIGO/Virgo S190517h : No counterpart candidate in TAROT-GRANDMA observations.
  12. LIGO/Virgo S190512at: SVOM/GWAC-F60A observations
  13. GRB 190519A: CALET Gamma-Ray Burst Monitor detection
  14. GRB 190519A: Swift-XRT refined Analysis
  15. LIGO/Virgo S190519bj Global MASTER-Net observations report
  16. GRB 190519A: Fermi GBM observation
  17. GRB 190519A: Fermi GBM Final Real-time Localization
  18. Fermi GRB190517.81 Global MASTER-Net observations report
  19. LIGO/Virgo S190517h: HAWC follow-up
  20. LIGO/Virgo S190517h Global MASTER-Net observations report
  21. GRB 190515B: Swift-XRT refined Analysis
  22. LIGO/Virgo S190513bm : TAROT-Calern and TAROT-Chile (TCA/TCH)/GRANDMA observation report.
  23. LIGO/Virgo S190513bm: Lick/KAIT Follow-Up Observations
  24. LIGO/Virgo S190510g: Further KMTNet observation of DECam-GROWTH and DESGW candidates
  25. LIGO/Virgo S190513bm Global MASTER-Net observations report
  26. LIGO/Virgo S190510g: Pan-STARRS and ATLAS observations and candidates
  27. LIGO/Virgo S190512at Global MASTER-Net observations report
  28. GRB 190512A: Fermi GBM observation
  29. Fermi GRB190512.61 Global MASTER-Net observations report
  30. GRB 190511A: Swift-XRT refined Analysis
  31. LIGO/Virgo S190510g: KMTNet observation of DECam-GROWTH and DESGW candidates
  32. LIGO/Virgo S190510g: Update on candidate significance
  33. GRB 190511A: Fermi-LAT detection
  34. LIGO/Virgo S190510g: Dabancheng/HMT Follow-Up Observations
  35. LIGO/Virgo S190510g: Xinglong/Schmidt Follow-Up Observations
  36. GRB 190511A: Fermi GBM Final Real-time Localization
  37. LIGO/Virgo S190510g: CNEOST Follow-Up Observations
  38. LIGO/Virgo S190510g: Lick/KAIT Follow-Up Observations
  39. LIGO/Virgo S190510g: Lulin Optical Follow-up Observations
  40. Konus-Wind observation of GRB 190501A
  41. LIGO/Virgo S190510g: HSC Y-band follow-up observation
  42. GRB 190508B: Fermi GBM Final Real-time Localization
  43. Fermi GRB190507.97 Global MASTER-Net observations report
  44. Fermi GRB190507.27 Global MASTER-Net observations report
  45. IceCube-190504A: MASTER optical monitoring analysis
  46. Fermi GRB190505.05 Global MASTER-Net observations report
  47. Fermi GRB190504.68 Global MASTER-Net observations report
  48. LIGO/Virgo S190503bf Global MASTER-Net observations report
  49. IceCube-190503A: Lick/KAIT Follow-Up Observations
  50. IPN Triangulation of GRB 190501A (long/bright)
  51. LIGO/Virgo S190425z: Konkoly imaging of target galaxies
  52. Fermi GRB190501.79 Global MASTER-Net observations report
  53. GRB 190501A: AGILE/MCAL and scientific ratemeters detection of a burst
  54. LIGO/Virgo S190425z: Gaia Photometric Alerts transient candidates
  55. LIGO/Virgo S190426c: PS1 historical detections and ZTF photometry of Gaia19boq AT2019egk
  56. LIGO/Virgo S190426c: YAHPT Optical Observation
  57. LIGO/Virgo S190426c: Fermi-LAT search for a high-energy gamma-ray counterpart
  58. LIGO/Virgo S190426c: OAJ-GRANDMA observation report
  59. LIGO/Virgo S190425z: MASTER explanation of the nature of an optical flash detected by a Swift as a short flare on a fast-moving WISE brown
  60. LIGO/Virgo S190426c: ASAS-SN observations
  61. LIGO/Virgo S190425z: KPED Follow-Up of ZTF transients
  62. LIGO/Virgo S190425z: Additional Candidates from the Zwicky Transient Facility
  63. LIGO/Virgo S190426c: DDOTI/OAN Optical Observations
  64. LIGO/Virgo S190425z: ASAS-SN observations
  65. LIGO/Virgo S190426c: RATIR Optical and NIR Observations of Galaxies
  66. LIGO/Virgo S190426c: COATLI Optical Observations of Galaxies
  67. LIGO/Virgo S190426c: Lick/KAIT Follow-Up Observations
  68. LIGO/Virgo S190426c: CNEOST Optical Observations
  69. LIGO/Virgo S190425z: CNEOST Optical Observations
  70. LIGO/Virgo S190425z: BOOTES-5/JGT observations of galaxies
  71. LIGO/Virgo S190425z: Lijiang 2.4-m Telescope Follow-up Observations
  72. LIGO/Virgo S190425z: Fermi-LAT search for a high-energy gamma-ray counterpart
  73. LIGO/Virgo S190425z: Additional Pan-STARRS transients in the skymap
  74. LIGO/Virgo S190425z: GRANDMA follow-up observations with Les Makes-T60, AZT-8 and Abastumani-T70
  75. LIGO/Virgo S190426c: Tentative Red Transient Candidate from Las Cumbres Observatory
  76. LIGO/Virgo S190426c: SAO optical observation
  77. LIGO/Virgo S190425z: Further MMT Follow-Up Observations
  78. LIGO/Virgo S190425z: COATLI Observations of Galaxies
  79. LIGO/Virgo S190425z: RATIR Observations of Galaxies
  80. LIGO/Virgo S190426c: Identification of a GW compact binary merger candidate
  81. LIGO/Virgo S190425z: KMTNet Observation
  82. LIGO/Virgo S190425z: Swope follow-up observations
  83. LIGO/Virgo S190425z: Las Cumbres Observatory Galaxy Targeted Counterpart Search
  84. Problem with GCN Circular and status of the fix
  85. LIGO/Virgo S190425z: KPED Follow-Up Observations
  86. LIGO/Virgo S190425z: Lulin Follow-Up Observations
  87. LIGO/Virgo S190425z: J-GEM optical follow-up observations with Subaru/FOCAS
  88. LIGO/Virgo S190425z: Xinglong/Schmidt follow-up observations
  89. LIGO/Virgo S190425z: Lick/KAIT Follow-Up Observations
  90. LIGO/Virgo S190425z: further analysis of INTEGRAL data
  91. LIGO/Virgo S190421ar: Fermi-LAT search for a high-energy gamma-ray counterpart
  92. Fermi GRB190425.09 Global MASTER-Net observations report
  93. LIGO/Virgo S190421ar: Lick/KAIT Follow-Up Observations
  94. GRB 190422A: Swift-XRT refined Analysis
  95. Fermi GRB190422.96 Global MASTER-Net observations report
  96. Fermi GRB190422.67 Global MASTER-Net observations report
  97. LIGO/Virgo S190421ar Global MASTER-Net observations report
  98. Fermi GRB190419.41 Global MASTER-Net observations report
  99. LIGO/Virgo S190412m: TAROT-GRANDMA observation report.
  100. GRB 190404C: MITSuME Akeno and Okayama optical upper limits

Advanced

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