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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"

45729 results found.

  1. EP241103a: Gemini optical limits
  2. EP241103a: EP observation update
  3. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  4. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  5. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  6. EP241103a: GSP optical upper limit
  7. EP241103A: LCO optical observations
  8. EP241103a: Global MASTER-Net observations report
  9. EP241103a: an X-ray transient detected by Einstein Probe
  10. GRB 241030A: Rapid release of TESS data.
  11. EP241101a: Global MASTER-Net observations report
  12. GRB 241029A: GRBAlpha detection
  13. EP241101a: BOOTES-7 optical upper limit
  14. LIGO/Virgo/KAGRA S241101ee: Updated Sky localization
  15. S241102cy: Identification of a GW compact binary merger candidate
  16. LIGO/Virgo/KAGRA S241102br: NED Galaxies in the Localization Volume
  17. LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate
  18. Kinder optical follow-up observations of EP241021a, EP241026b, and EP241030a/GRB241030A
  19. GRB241030A: OHP/T193 optical observations
  20. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  21. EP241101a: EP-WXT detection of a fast X-ray transient
  22. Swift GRB 241101A: Global MASTER-Net observations report
  23. GRB 241101A: FRAM-ORM optical limit
  24. LIGO/Virgo/KAGRA S241101ee: Identification of a GW compact binary merger candidate
  25. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  26. EP241021a: Upper limit from Konus-Wind observations
  27. GRB 241101A: Swift-BAT refined analysis
  28. GRB 241030A: further SAO RAS optical observations
  29. GRB 241030A: Optical Observations via Virtual Telescope Project
  30. EP241021a: Liverpool Telescope optical follow-up observations
  31. GRB 241030B: Swift-XRT refined Analysis
  32. GRB 241026A: SAO RAS optical observations
  33. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  34. EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow
  35. GRB 241101A: Swift detection of a burst
  36. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits (duplicate submission of 38023)
  37. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  38. EP241021a: OHP/T193 optical observations
  39. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  40. GRB 241030B: Montarrenti Observatory optical upper limit
  41. GRB 241030A / EP241030a: FTW Optical and NIR observations of the optical counterpart
  42. EP241026b: Liverpool Telescope optical follow-up
  43. Fermi trigger No 752083996: Global MASTER-Net observations report
  44. GRB 241030A: SAO RAS optical observations
  45. GRB 241030A: Fermi GBM Observation
  46. EP241021a: AMI-LA radio detection
  47. GRB 241030B : GIT optical upper limits
  48. GRB 241030B: LCOGT Optical Upper Limits
  49. GRB 241030B: Swift-BAT refined analysis
  50. GRB 241030A: Swift-BAT refined analysis
  51. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  52. GRB 241030B: Swift/UVOT Detection
  53. EP EP241030a: Global MASTER-Net observations report
  54. GRB 241029A: LCO optical detection
  55. Fermi trigger No 752006065: Global MASTER-Net observations report
  56. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  57. Swift GRB241030.77: Global MASTER-Net observations report
  58. GRB 241030B: SVOM/GRM observation
  59. GRB 241030B : MITSuME Akeno optical upper limits
  60. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  61. GRB 241030B: SVOM/VT optical afterglow observations
  62. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  63. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  64. GRB241030B: Fermi GBM Observation
  65. GRB 241030B: BTA observations
  66. GRB 241029A: SVOM/VT optical afterglow observations
  67. GRB 241030A: detection of the bright optical counterpart in ATLAS forced photometry
  68. GRB 241030B: Enhanced Swift-XRT position
  69. GRB 241030B: optical observations from the INAF Asiago Observatory
  70. EP241021a: Swift-UVOT detection
  71. GRB241030B: GRANDMA/TAROT Upper Limit
  72. GRB 241030A: Swift-XRT refined Analysis
  73. GRB 241030B: SAO RAS optical observations
  74. GRB 241030B: AKO Optical Afterglow Detection
  75. GRB 241030B: Nanshan/HMT optical afterglow detection
  76. GRB 241030B: SVOM/ECLAIRs detection of a burst
  77. GRB 241030B: Prompt enhanced Swift-XRT position
  78. Konus-Wind detection of GRB 241030A
  79. GRB 241030B: Swift detection of a burst
  80. GRB 241030B: Fermi GBM Final Real-time Localization
  81. GRB 241030A: Fermi-LAT detection
  82. GRB 240912A: radio detection with the VLA
  83. Fermi GRB 241030A: Global MASTER-Net observations report
  84. GRB 241030A: AKO Optical Afterglow Detection
  85. Swift GRB 241030A: Global MASTER-Net observations report
  86. GRB 241030A: Swift/UVOT Detection
  87. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  88. GRB 241030A: SVOM/GRM observation
  89. GRB 241026A: Swift-BAT refined analysis
  90. GRB 241030A: SVOM/C-GFT optical observations
  91. GRB 241026A: LBT optical observations
  92. EP241021a: Optical rebrightening observations with Mephisto
  93. EP241026b: EP-FXT follow-up observation
  94. GRB 241030A: Multiband optical detection with Mephisto
  95. GRB 241030A: SVOM/VT optical afterglow observations
  96. GRB 241025A: The discovery of a BdHN I from data of Swift, Fermi, SVOM and Einstein Probe telescopes
  97. GRB 241030A : MITSuME Akeno optical afterglow detection
  98. GRB 241030A: Enhanced Swift-XRT position
  99. GRB 241029A: GROWTH-India Telescope optical follow up
  100. GRB 241030A: TRT optical observations

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