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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"

31730 results found.

  1. GRB 240809A: GIT afterglow observations
  2. GRB 240809A: Swift/UVOT Detection
  3. GRB 240809A: Tentative redshift from NOT
  4. IPN triangulation of GRB 240807A / EP 240807a
  5. LIGO/Virgo/KAGRA S240807h: Updated Sky localization and EM Bright Classification
  6. X-ray Transient EP240807a: PRIME near-infrared upper limits
  7. Swift GRB 240809A: Global MASTER-Net observations report
  8. GRB 240809A: JinShan optical observations
  9. GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
  10. GRB 240809A: SVOM/GRM observation
  11. GRB 240807A: SVOM/GRM observation
  12. EP-WXT trigger 01709018832: SVOM/C-GFT observations of the star flare
  13. EP240807a: STEP/T80S optical limits
  14. GRB 240807B: AstroSat CZTI detection of a short burst
  15. EP EP240807a: Global MASTER-Net observations report
  16. EP EP240806a: Global MASTER-Net observations report
  17. GRB 240801A: GRBAlpha detection
  18. GRB 240710B: VZLUSAT-2 detection
  19. GRB 240805A: ATCA Radio Upper Limits
  20. EP240807a/GRB 240807A: EP-FXT detection of the X-ray emission
  21. S240807h: Identification of a GW compact binary merger candidate
  22. EP240802a/GRB240802A: KAIT optical upper limit
  23. GRB 240720B: VZLUSAT-2 detection
  24. GRB 240710A: VZLUSAT-2 detection
  25. EP240806A: Liverpool Telescope optical follow-up observations
  26. EP240806a: Gemini North-GMOS spectroscopic redshift of z = 2.818
  27. GRB 240805B: GIT optical upper limit
  28. EP240806a: KAIT optical observations
  29. GRB 240805B: Swift-BAT refined analysis
  30. GRB 240805A: Swift-BAT refined analysis
  31. EP240804a (GRB 240804B): NOT optical observations
  32. EP240806a: LCOGT optical counterpart detection
  33. Konus-Wind detection of GRB 240802A (EP240802a)
  34. Improved IPN triangulation of GRB 240802A / EP 240802a
  35. Konus-Wind detection of GRB 240805A
  36. GRB 240805B Bassano Bresciano Observatory upper limit
  37. GRB240805A: Fermi GBM Observation
  38. GRB 240805B: JinShan optical afterglow detection
  39. GRB 240804B/EP240804a: Correction to the GRB name in GCN 37071
  40. GRB 240805B: AbAO, CrAO, and Terskol optical upper limits
  41. Konus-Wind detection of GRB 240804B (a counterpart of EP240804a)
  42. EP240806a: EP-FXT detection of the X-ray emission
  43. GRB 240624B: VZLUSAT-2 detection
  44. GRB 240619C: VZLUSAT-2 detection
  45. EP 240806A: LCO optical observations
  46. GRB 240805B: Optical detection with 1.6m Mephisto
  47. GRB 240805B: NUTTelA-TAO / BSTI Optical Limits
  48. GRB 240805B: Swift/UVOT Upper Limits
  49. GRB 240805A: Swift/UVOT Upper Limits
  50. GRB 240805B: BTA optical afterglow candidate
  51. GRB 240805A: SVOM/GRM observation
  52. GRB 240805B: LCOGT Optical Upper Limits
  53. Swift GRB 240805B: Global MASTER-Net observations report
  54. GRB 240805B: JinShan optical upper limits
  55. EP240801a: BTA BVRI photometry
  56. Fermi GRB 240805A: Global MASTER-Net observations report
  57. Swift GRB 240805A: Global MASTER-Net observations report
  58. GRB 240805A: Fermi-LAT detection
  59. GRB 240805A: INTEGRAL spectral analysis
  60. EP240801a: Continued optical observations at ZTSh (CraO)
  61. EP240804a: VLT/X-shooter spectroscopic redshift
  62. EP240804a: LCOGT optical counterpart detection
  63. GRB 240805A: A long GRB detected by INTEGRAL
  64. EP240804a: NOT optical counterpart detection
  65. EP240802a: correction of EP-WXT trigger time in GCN 37019
  66. Fermi GRB 240804A: Global MASTER-Net observations report
  67. EP240802a: Montarrenti Observatory optical upper limit
  68. IPN triangulation of GRB 240802A / EP 240802a
  69. EP240801a: Osservatorio Astronomico Nastro Verde upper limit
  70. EP240802A: Bassano Bresciano Observatory upper limit
  71. GRB 240802A: SVOM/GRM observation
  72. EP240802a: Time coincidence with GRB 240802A and optical upper limits with Kinder observations
  73. EP240801a: further SAO RAS optical observations
  74. EP240801a: optical observations at CrAO and AbAO
  75. EP240801a: GRANDMA and Kilonova-Catcher optical observations
  76. EP240801a: Leavitt Observatory optical observations
  77. EP240801a: GTC spectroscopy and absorption redshift
  78. EP240801a: SAO RAS optical observations
  79. GRB 240801B: AstroSat CZTI Updated classification - likely a solar flare
  80. EP240801a: JinShan optical observations
  81. GRB 240727C: SVOM/GRM observation
  82. EP240801a: NOT optical observations
  83. EP240801a: follow-up observation with LCOGT
  84. Fermi GBM trigger 744179961 / 240801194 can not be confirmed as a GRB
  85. GRB 240730A: Swift-BAT refined analysis
  86. EP240801a: GSP follow-up observations of the candidate counterpart
  87. EP240801a: Kinder follow-up observations of the candidate counterpart
  88. EP240708a: Kinder follow-up observations of the candidate counterpart (duplicate submission of GCN 37002)
  89. EP240801a: KAIT optical counterpart observations
  90. EP240801a: GMG observation
  91. EP240801a: TRT optical counterpart detection
  92. Fermi GRB 240801A: Global MASTER-Net observations report
  93. GRB 240731A: Fermi GBM Final Localization
  94. GRB 240730A: Osservatorio Astronomico Nastro Verde upper limit
  95. Fermi GRB 240730B: Global MASTER-Net observations report
  96. Swift GRB 240730A: Global MASTER-Net observations report
  97. GRB 240715A: Swift-XRT afterglow detection
  98. GRB 240730A: KAIT Optical Upper Limit
  99. GRB 240727C: GRBAlpha detection
  100. GRB 240730A: Swift/UVOT Upper Limits

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