Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

25904 results found.

  1. GRB 230815A: Enhanced Swift-XRT position
  2. GRB 230812B: Iota Scorpii Observatory, La Spezia, Italy
  3. GRB 230815A: Swift detection of a burst
  4. GRB 230812B: AMI-LA radio detection of afterglow candidate
  5. GRB 230812B: continued AbAO optical afterglow observations
  6. GRB 230812B: Further Bassano Bresciano Observatory optical observations
  7. GRB 230812B: Upper limits from a neutrino search with IceCube
  8. GRB 230812B: GRANDMA further observations of ZTF23aaxeacr candidate afterglow
  9. GRB 230812B: CrAO ZTSh optical observations
  10. GRB 230812B: Koshka Zeiss-1000 optical observations
  11. GRB 230812B: GIT optical follow-up
  12. GRB 230812B: Leavitt Observatory optical observations
  13. GRB 230812B: Bassano Bresciano Observatory optical observations
  14. GRB 230812B: Faulkes Telescope North optical afterglow follow-up
  15. GRB 230812B: Osservatorio Astronomico "Nastro Verde" optical observation
  16. GRB 230812B: OASDG optical observations
  17. GRB 230812B: AbAO optical observations
  18. GRB 230812B: Spectroscopy from NOT
  19. GRB 230812B: Redshift from OSIRIS+/GTC
  20. GRB 230812B: Detected Optical Afterglow Candidate
  21. GRB 230812B: GMG - GRANDMA observations
  22. GRB230812B: AGILE/MCAL detection
  23. GRB 230812B: Swift-XRT afterglow detection
  24. GRB 230812: Swift/UVOT Detection
  25. GOTO confirmation and possible host galaxy of GRB230812B optical afterglow
  26. GRB 230812B: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi GRB (Trigger 713559497)
  27. Fermi GRB 230812B: MASTER optical counterpart
  28. GRB 230812B: KAIT Optical Afterglow Candidate
  29. GRB 230812B: Improved Swift/XRT localization
  30. GRB 230812B: Preliminary Swift/XRT localization
  31. GRB 230812B: Tiled Swift observations
  32. ZTF23aaoohpy/AT2023lcr: JWST spectroscopy confirmation of an associated type Ic-BL supernova
  33. GRB 230808A: Fermi GBM Detection
  34. GRB 230805B: Swift-BAT refined analysis
  35. GRB 230805B: Iota Scorpii Observatory, La Spezia, Italy upper limit
  36. GRB 230805B: AstroSat CZTI detection
  37. GRB 230808A: Swift/BAT-GUANO detection of a burst
  38. ZTF23aaoohpy/AT2023lcr: JWST observations consistent with the presence of a supernova
  39. GRB 230805B : MITSuME Akeno optical upper limits
  40. LIGO/Virgo/KAGRA S230805x: Upper limits from Swift/BAT-GUANO
  41. GRB 230805B: Fermi GBM observation
  42. GRB 230805B: Enhanced Swift-XRT position
  43. GRB 230805B: Swift/UVOT Upper Limits
  44. GRB 230805B: Bassano Bresciano observatory upper limit
  45. GRB 230805B: BOOTES-6/DPRT optical upper limit and 1.5m OSN detection
  46. GRB 230805B: NOT optical afterglow confirmation
  47. GRB 230805B: Swift-XRT refined Analysis
  48. GRB 230805B: SAO RAS optical observations
  49. Swift GRB 230805B: Global MASTER-Net observations report
  50. GRB 230805B: Swift detection of a burst
  51. GRB 230802A: Fermi GBM observation
  52. GRB 230802A: Swift-BAT refined analysis
  53. GRB 230802A: Swift/UVOT Upper Limits
  54. Swift GRB 230802A: Global MASTER-Net observations report
  55. GRB 230802A: BOOTES-5/JGT optical upper limit
  56. GRB 230802A: Swift-XRT refined Analysis
  57. GRB 230802A: Enhanced Swift-XRT position
  58. GRB 230802A: Swift detection of a burst
  59. LIGO/Virgo/KAGRA S230731an: Upper limits from Swift/BAT-GUANO
  60. GRB 230728A: Swift-BAT refined analysis
  61. GRB 230723B: Swift-BAT refined analysis
  62. GRB 230723B: MITSuME Ishigaki optical observation
  63. GRB 230728A: BOOTES-1 optical upper limit
  64. GRB 230728A: Fermi GBM Observation
  65. GRB 230728A: LCOGT Optical Upper Limit
  66. GRB 230728A: Swift/UVOT Upper Limits
  67. GRB 230728A: Swift-XRT refined Analysis
  68. GRB 230728A: Enhanced Swift-XRT position
  69. GRB 230728A: NOT optical observations and possible host galaxy
  70. GRB 230727A: AstroSat CZTI detection
  71. GRB 230728A: Swift detection of a burst
  72. Swift GRB230728.12: Global MASTER-Net observations report
  73. GRB 230727A: Swift/BAT-GUANO detection of a burst
  74. GRB 230723B: Further CAHA observations and host galaxy detection
  75. GRB 230723B: MITSuME Akeno optical afterglow candidate detection
  76. GRB 230723B: ATCA rapid radio follow-up
  77. IBAS trigger number 10337: not a real GRB
  78. GRB 230723B: GAD Observatory, La Spezia, Italy upper limit
  79. GRB 230723B: Leavitt Observatory upper limit
  80. GRB 230723B: Osservatorio Astronomico Nastro Verde upper limit
  81. GRB 230723B: Montarrenti Observatory upper limit
  82. GRB 230723B: Optical afterglow candidate from CAHA
  83. GRB 230723B: Bassano Bresciano Observatory upper limit
  84. GRB 230723B: Fermi GBM observation
  85. GRB 230723B: Swift-XRT refined Analysis
  86. GRB 230723B: non-detections from Observatoire de Haute-Provence
  87. GRB 230723B: Optical limit from CAHA
  88. GRB 230723B: Swift/UVOT Upper Limits
  89. Swift GRB 230723B: Global MASTER-Net observations report
  90. Swift-XRT position for GRB 230723B
  91. GRB 230723B: Swift-XRT observations
  92. GRB 230723B: Swift detection of a burst
  93. Swift GRB230720.30: Global MASTER-Net observations report
  94. IPN triangulation of GRB 230715D
  95. Swift Trigger 1180063 is not a GRB
  96. Swift Trigger 1180060 is not a GRB
  97. Swift Trigger 1180055 is not a GRB
  98. IPN triangulation of GRB 230712C (short)
  99. IPN triangulation of GRB 230712A (short)
  100. IceCube-230707A : MAXI upper limit and NICER follow-up observation of Swift J1753.5-0127

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