Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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').
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"

112 results found.

  1. Fermi GRB 250916A: Global MASTER-Net observations report
  2. GRB 240315B: AstroSat CZTI detection
  3. GRB 231129C: AGILE detection
  4. LIGO/Virgo S230525a: Global MASTER-Net observations report
  5. GRB230414B: VIRT Optical Upper Limit
  6. Fermi GRB 210615A: Global MASTER-Net observations report
  7. Fermi GBM observation of a bright burst from magneta
  8. LIGO/Virgo S200208q: Upper limits from Fermi-GBM Observations
  9. LIGO/Virgo S200208q: Identification of a GW compact binary merger candidate
  10. Fermi trigger No 588838851 Global MASTER-Net observations report
  11. GRB180523B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 548793993)
  12. Swift triggered on SAX J1806.5-221
  13. GRB 161214B: Swift detection of a burst
  14. GRB 160409A found in Swift BAT ground analysis
  15. Trigger 659734: Swift detection of SAX J1750.8-2900 or other source near Galactic center
  16. Konus-Wind observation of GRB 151006A
  17. Swift detection of SAX J1808.4-3658
  18. Swift detection of SAX J1712.6-3739
  19. Swift-BAT trigger 536502 is not astrophysical
  20. Swift Trigger 536502 is likely a noise fluctuation in coincidence with SAX J1818.6-1703
  21. Swift-BAT trigger 535733 is not astrophysical
  22. Trigger 535733: Swift possible detection of SAX J1828.5-1037
  23. SAX J1818.6-1703: Swift detection (trigger 306379)
  24. UVOT observations of SAXJ1810.8-2609
  25. Swift detection of a outburst from SAX J1810.8-2609
  26. GRB060604: Swift/UVOT detections
  27. GRB 060206: RAPTOR observations of afterglow candidate variability.
  28. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  29. IPN triangulation of GRB030717 (annulus)
  30. BeppoSAX GRB : GRB020409
  31. GRB020322: Candidate Optical Afterglow
  32. Bepposax GRB020322 The second springtime BSAX GRB
  33. GRB 011211 Optical Observations: Likely Afterglow
  34. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  35. GRB011121: BeppoSAX-WFC refined positions
  36. BEPPOSAX GRB011121
  37. The X-ray Flash 011030 ('GRB 011030')
  38. IPN triangulation of GRB010629
  39. Support extension to the BeppoSAX mission
  40. GRB010222: possible optical counterpart
  41. GRB010222
  42. GRB 010214, Optical Observations
  43. GRB000528, Radio Observations
  44. IPN triangulation of GRB000516
  45. BeppoSAX GRB000424
  46. GRB000419 [IPN Position]
  47. 1SAXJ1715.0-7134 refined position
  48. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  49. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  50. Budget cuts in BeppoSAX operations: impact on GRB observations
  51. GRB000226 [IPN Position]
  52. GRB 000210: BATSE Observations
  53. GRB000210, Radio Observations
  54. SAX_WFC_GRB_NOTICE
  55. SAX_WFC_GRB_NOTICE
  56. GCN resumes full operations
  57. IPN error box for GRB991216
  58. GRB 991217 (SAX J2303.2+0015) Optical observations
  59. GRB991217/SAX J2303.2+0015, optical observations
  60. SAX J2303.2+0015 Optical observations
  61. GRB 991217 (SAX J2303.2+0015) Optical observations
  62. GRB 991217
  63. SAX J2303.2+0015: an x-ray/GRB?
  64. BeppoSAX NFI Observation of GRB991106
  65. GRB 991105: BATSE Observations
  66. BeppoSAX refined position for GRB991106
  67. GRB991105: SAX-GRBM/-WFC detection
  68. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  69. GRB ALERT: GRB991105
  70. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  71. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  72. GRB990806 BeppoSAX follow up
  73. GRB 990712
  74. Infrared and Optical Observations of GRB990705
  75. GRB990704: SAX-NFI results summary
  76. GRB 990704 X-ray Observations
  77. GRB990705: Intriguing Positional Coincidences
  78. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  79. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  80. Optical report on X-ray/GRB transient
  81. BeppoSAX: A new fast X-ray transient
  82. GRB990123, Probability of gravitational lensing
  83. GRB990123 IPN annulus
  84. GRB990123, refined SAX-WFC position
  85. GRB 981226 Optical Observations
  86. GRB981226 BeppoSAX follow up
  87. GRB980425: X-ray revised positions
  88. GRB980519, Optical Observations
  89. GRB980703, Host galaxy multicolor photometry
  90. GRB 980703 (NFI observations)
  91. BeppoSAX NFI observations of GRB 980703
  92. GRB980703
  93. GRB980613, optical observations
  94. GRB 980613 Optical Observations
  95. GRB980613 BeppoSAX-NFI follow up
  96. GRB980613, BeppoSAX WFC positions
  97. GRB980519 IPN POSITION
  98. GRB980515: SAX-WFC updated position
  99. BSAX Observations of GRB980425 field
  100. GRB980425 BATSE observations

Advanced

Download all Circulars as a .tar.gz archive:
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